Chapter 4

Question 13 out of 3 points

Which of the following "buds off" of the Golgi complex?Selected Answer:

vesicles

Question 23 out of 3 points

Which of the following does NOT possess a double membrane?Selected Answer:

ribosome

Question 33 out of 3 points

If a cell contains large amounts of rough ER, then:Selected Answer:

large amounts of protein hormones could be exported by the cell.

Question 43 out of 3 points

The formation of ATP in the mitochondria, which is an oxygen-dependent reaction, is called:Selected Answer:

aerobic metabolism.

Question 53 out of 3 points

Prokaryotes that are rod-shaped are called:Selected Answer:

bacilli.

Question 63 out of 3 points

Which of the following is the smallest?Selected Answer:

virus

Question 73 out of 3 points

Which of the following is a FALSE statement about prokaryotes?Selected Answer:

Prokaryotes are so small that they can be seen only with an electron microscope.

Question 83 out of 3 points

A particular cell has the following molecules and structures: enzymes, DNA, ribosomes, plasma membrane, and mitochondria. It could be a(n) ________ cell.

Selected Answer:

plant or animal

Question 93 out of 3 points

If all of the lysosomes within a cell suddenly ruptured, what could occur?Selected Answer:

The biological molecules in the cell would begin to degrade.

Question 103 out of 3 points

What is the difference between "free" and "attached" ribosomes?Selected Answer:

Free ribosomes occur in the cytoplasm, whereas attached ribosomes are found on the endoplasmic reticulum.

Question 113 out of 3 points

Cells that primarily produce steroid hormones, such as testosterone and estrogen, have large quantities of:Selected Answer:

smooth endoplasmic reticulum.

Question 123 out of 3 points

Which of the following is visible ONLY with an electron microscope?Selected Answer:

large protein

Question 133 out of 3 points

Which of the following statements does NOT agree with the cell theory?Selected Answer:

Minerals in the diet are important for good health.

Question 143 out of 3 points

Which of the following is the thinnest?Selected Answer:

a microfilament

Question 153 out of 3 points

Which type of microscope has the best resolution?Selected Answer:

an electron microscope

Question 163 out of 3 points

What is NOT a feature of a prokaryotic cell?Selected a nuclear membrane

Answer: Question 17

3 out of 3 pointsMembrane proteins are synthesized on ribosomes that are found:Selected Answer:

on the rough endoplasmic reticulum.

Question 183 out of 3 points

The cytoplasm of eukaryotic cells contains all of the following EXCEPT:Selected Answer:

chromosomes.

Question 193 out of 3 points

All the following are important functions of the cytoskeleton EXCEPT:Selected Answer:

storage of food molecules.

Question 203 out of 3 points

Which cellular organelle packages enzymes and forms lysosomes?Selected Answer:

Golgi apparatus

Question 213 out of 3 points

Mitochondria and chloroplasts share all of the following characteristics EXCEPT that they:Selected Answer:

capture the energy of sunlight to meet metabolic demands.

Question 223 out of 3 points

All of the following are components of the modern cell theory EXCEPT:Selected Answer:

Bacterial cells are eukaryotic.

Question 233 out of 3 points

Which of the following provides evidence that mitochondria and chloroplasts were once free-living prokaryotic organisms?Selected Answer:

They contain their own DNA.

Question 243 out of 3 points

Of the objects listed, which is the smallest that you can see with the unaided eye?

Selected Answer:

frog embryo

Question 250 out of 3 points

Phospholipids are:Selected Answer:

completely hydrophobic.

Question 263 out of 3 points

______________ (two words) is a stack of flattened membranous sacs.Selected Answer:

Golgi Apparatus

Question 273 out of 3 points

The DNA in a prokaryotic cell is in the ________ region of the cytoplasm.Selected Answer:

nucleoid

Question 283 out of 3 points

This cytoskeletal element allows muscle contraction? ____________.Selected Answer:

microfilament

Question 293 out of 3 points

This cytoskeletal element supports cilia? ____________ .Selected Answer:

microtubules

Question 303 out of 3 points

______________ are the “workbenches" of the cell.Selected Answer:

Ribosomes

Question 310 out of 3 points

The ________ in prokaryotic cells may help some pathogenic bacteria evade their host's immune system and attach to host cells.Selected Answer:

slime layer

Question 323 out of 3 points

The ________ is an organelle where some of the proteins synthesized on ribosomes and rough ER are processed.Selected Answer:

Golgi apparatus

Question 334 out of 4 points

Antibody proteins are synthesized on ribosomes associated with the _____[a]________ (three words). The antibody proteins are packaged into membranous sacs called _____[b]________ and are then transported to the ______[c]________ (two words).  Here, what type of molecule is added to the protein? _____[d]________.  After the antibody is completed, it is packaged into vesicles that fuse with the _____[e]_______ (two words).Specified Answer for: a

rough endoplasmic reticulum

Specified Answer for: b

vesicles

Specified Answer for: c

Golgi apparatus

Specified Answer for: d

carbohydrates

Specified Answer for: e

plasma membrane

Question 344 out of 4 points

The plasma membrane is composed of two major types of molecules, ____ [a] ____  and ____ [b] ____  .  Which type of molecule is responsible for each of the following functions?  Isolation from the surroundings: ____ [c] ____  ;· interactions with other cells: ____ [d] ____  .Specified Answer for: a

phospholipids

Specified Answer for: b

proteins

Specified Answer for: c

phospholipids

Specified Answer for: d

proteins

Question 352 out of 2 points

Cells that have a nucleus are referred to as ___[a]_____ cells; those that lack a true nucleus are called ___[b]_____ cells.Specified Answer for: a

eukaryotic

Specified Answer for: b

prokaryotic

Question 13 out of 3 points

If you removed the sex pili from a bacterial cell, then the:

Selected Answer:

bacterium could no longer exchange DNA with other cells.

Question 23 out of 3 points

A cell with a large number of lysosomes would most likely be very active in:

Selected Answer:

phagocytosis.

Question 33 out of 3 points

Which of the following is associated with rough ER?

Selected Answer:

ribosomes

Question 43 out of 3 points

Fibers of the cytoskeleton are composed of primarily:

Selected Answer:

proteins.

Question 53 out of 3 points

All of the following are dependent on cilia EXCEPT the:

Selected Answer:

sperm of animals.

Question 63 out of 3 points

Which type of microscope has the best resolution?

Selected Answer:

an electron microscope

Question 73 out of 3 points

Which of the following cell structures is not found in a bacterial cell?

Selected Answer:

endoplasmic reticulum

Question 83 out of 3 points

Which is a difference between prokaryotes and eukaryotes?

Selected Answer:

Prokaryotes have a nucleoid, whereas eukaryotes have a nucleus.

Question 93 out of 3 points

A cell from a wheat plant contains all of the following EXCEPT a:

Selected Answer:

contractile vacuole.

Question 103 out of 3 points

A particular cell has the following molecules and structures: enzymes, DNA, ribosomes, plasma membrane, and mitochondria. It could be a(n) ________ cell.

Selected Answer:

plant or animal

Question 113 out of 3 points

Ribosomes are the site of synthesis of:

Selected Answer:

proteins.

Question 120 out of 3 points

What primarily determines the shape of animal cells, which lack cell walls?

Selected Answer:

ribosomes

Answers: nucleus

cytoplasm

endoplasmic reticulum

cytoskeleton

ribosomes

Question 133 out of 3 points

The formation of ATP in the mitochondria, which is an oxygen-dependent reaction, is called:

Selected Answer:

aerobic metabolism.

Question 143 out of 3 points

What is the difference between "free" and "attached" ribosomes?

Selected Answer:

Free ribosomes occur in the cytoplasm, whereas attached ribosomes are found on the endoplasmic reticulum.

Question 153 out of 3 points

All the following are important functions of the cytoskeleton EXCEPT:

Selected Answer:

storage of food molecules.

Question 163 out of 3 points

All of the following are components of the modern cell theory EXCEPT:

Selected Answer:

Bacterial cells are eukaryotic.

Question 173 out of 3 points

What is NOT a feature of a prokaryotic cell?

Selected Answer:

a nuclear membrane

Question 183 out of 3 points

Which of the following is a FALSE statement about prokaryotes?

Selected Answer:

Prokaryotes are so small that they can be seen only with an electron microscope.

Question 193 out of 3 points

Which of the following is capable of converting light energy into chemical energy?

Selected Answer:

chloroplasts

Question 203 out of 3 points

All cells possess all of the following components EXCEPT:

Selected Answer:

a nuclear membrane.

Question 213 out of 3 points

The major histocompatibility complex (MHC), which is a major recognition protein express on our cells is an example of a(n):

Selected Answer:

glycoprotein.

Question 223 out of 3 points

Cells that primarily produce steroid hormones, such as testosterone and estrogen, have large quantities of:

Selected Answer:

smooth endoplasmic reticulum.

Question 233 out of 3 points

What is the function of a plant cell vacuole?

Selected Answer:

stores water

Question 243 out of 3 points

Aerobic metabolism occurs in the:

Selected Answer:

mitochondrion.

Question 253 out of 3 points

Both prokaryotic and eukaryotic cells possess:

Selected Answer:

ribosomes.

Question 260 out of 3 points

RNA carries information for protein synthesis from the DNA in the nucleus to the ribosomes in the cytoplasm. To get from the nucleus to the cytoplasm, RNA must pass through ________ (two words) in the nuclear membrane.

Selected Answer:

endoplasmic reticulum

Question 273 out of 3 points

The DNA in a prokaryotic cell is in the ________ region of the cytoplasm.

Selected Answer:

nucleoid

Question 283 out of 3 points

Most of the cell's metabolic activities occur in the ________.

Selected Answer:

cytoplasm

Question 290 out of 3 points

The ________ in prokaryotic cells may help some pathogenic bacteria evade their host's immune system and attach to host cells.Selected Answer:

slime layer

Question 303 out of 3 points

The ________ is an organelle where some of the proteins synthesized on ribosomes and rough ER are processed.

Selected Answer:

Golgi apparatus

Question 313 out of 3 points

______________ (two words) comes in rough and smooth forms.

Selected Answer:

Endoplasmic reticulum

Question 320 out of 3 points

______________ propel fluid past cells.

Selected Answer:

flagella

Question 334 out of 4 points

Antibody proteins are synthesized on ribosomes associated with the _____[a]________ (three words). The antibody proteins are packaged into membranous sacs called _____[b]________ and are then transported to the ______[c]________ (two words).  Here, what type of molecule is added to the protein? _____[d]________.  After

the antibody is completed, it is packaged into vesicles that fuse with the _____[e]_______ (two words).Specified Answer for: a

rough endoplasmic reticulum

Specified Answer for: b

vesicles

Specified Answer for: c

Golgi apparatus

Specified Answer for: d

carbohydrates

Specified Answer for: e

plasma membrane

Question 344 out of 4 points

The plasma membrane is composed of two major types of molecules, ____ [a] ____  and ____ [b] ____  .  Which type of molecule is responsible for each of the following functions?  Isolation from the surroundings: ____ [c] ____  ;· interactions with other cells: ____ [d] ____  .Specified Answer for: a

phospholipids

Specified Answer for: b

proteins

Specified Answer for: c

phospholipids

Specified Answer for: d

proteins

Question 352 out of 2 points

Cells that have a nucleus are referred to as ___[a]_____ cells; those that lack a true nucleus are called ___[b]_____ cells.Specified Answer for: a eukaryot

ic

Specified Answer for: b prokaryotic

CHAPTER 5

Question 13 out of 3 points

Suppose you have two glucose solutions separated by a selectively permeable membrane. If there is a concentration gradient of glucose across the membrane, then one of the solutions cannot be:

Selected Answer:

isotonic.

Answers: hypotonic.

isotonic.

hypertonic.

Question 23 out of 3 points

If a frog egg cell is placed into a hypotonic solution, it will:

Selected Answer:

swell via osmosis.

Answers: shrivel via osmosis.

swell via osmosis.

shrivel via facilitated diffusion.

swell via facilitated diffusion.

shrivel via active transport.

Question 30 out of 3 points

Plasma membranes are BEST described as a:

Selected Answer:

double layer of phospholipids with hydrophilic heads directed toward one another.

Answers: double layer of phospholipids with hydrophobic tails directed toward the cytoplasm of the cell.

single layer of phospholipids with water molecules attached along one side.

double layer of phospholipids with hydrophilic heads directed toward one another.

double layer of phospholipids with hydrophobic tails oriented toward one another.

single layer of phospholipids with tails pointed toward the inside of the cell.

Question 43 out of 3 points

The gases O 2 and CO 2 enter or leave a plant cell by:

Selected Answer:

simple diffusion.

Answers: osmosis.

simple diffusion.

facilitated diffusion.

active transport.

facilitated transport.

Question 53 out of 3 points

The ________ portion of the cell membrane is responsible for the isolating function of the membrane, while the ________ portion regulates exchange and communication with the environment.

Selected Answer:

lipid; protein

Answers: lipid; protein

cholesterol; lipid

protein; cholesterol

carbohydrate; lipid

nucleic acid; lipid

Question 63 out of 3 points

For diffusion to occur, there must be:

Selected Answer:

a gradient.

Answers: a membrane.

a gradient.

water.

ATP.

Question 70 out of 3 points

Which of the following types of membrane proteins are responsible for connecting cells to one another?

Selected Answer:

receptor proteins

Answers: transport proteins

recognition proteins

enzymes

receptor proteins

attachment proteins

Question 83 out of 3 points

What structure in the membrane causes plasma membranes to resist freezing?

Selected Answer:

unsaturated fatty acid tails

Answers: polar heads of the phospholipids

channel proteins

cholesterol

saturated fatty acid tails

unsaturated fatty acid tails

Question 93 out of 3 points

Which of the following occurs as an enzyme produced by a cell is secreted from the cell?

Selected Answer:

exocytosis

Answers: endocytosis

phagocytosis

pinocytosis

receptor-mediated endocytosis

exocytosis

Question 103 out of 3 points

When a mouse cell and a human cell are fused, the membrane proteins of the two cells become uniformly distributed over the surface of the hybrid cell. This occurs because:

Selected Answer:

many proteins can move around within the bilayer.

Answers: many proteins can move around within the bilayer.

all proteins are anchored within the membrane.

proteins are asymmetrically distributed within the membrane.

all proteins in the plasma membrane are extrinsic.

different membranes contain different proteins.

Question 11

3 out of 3 pointsThe hydrophobic tails of a phospholipid bilayer are oriented toward the:

Selected Answer:

interior of the plasma membrane (i.e., toward one another).

Answers: interior of the plasma membrane (i.e., toward one another).

extracellular fluid surrounding the cell.

cytoplasm of the cell.

Question 123 out of 3 points

What prevents your immune system from attacking your own cells?

Selected Answer:

recognition proteins

Answers: inadequate enzymes

fever

cholesterol

recognition proteins

receptor proteins

Question 133 out of 3 points

The urinary bladder is protected from leaking due to cell-to-cell junctions called:

Selected Answer:

tight junctions.

Answers: desmosomes.

tight junctions.

gap junctions.

plasmodesmata.

Question 143 out of 3 points

Imagine that beaker A has a 10% sucrose solution, and beaker B has an 8% sucrose solution. This means that:

Selected Answer:

beaker A is hypertonic relative to beaker B.

Answers: beaker A is isotonic relative to beaker B.

beaker A is hypertonic relative to beaker B.

beaker A is hypotonic relative to beaker B.

Question 153 out of 3 points

Molecules that permeate a plasma membrane by facilitated diffusion:

Selected Answer:

require the aid of transport proteins.

Answers: require an expenditure of energy.

require the aid of transport proteins.

move from an area of low concentration to an area of high concentration.

do so much more quickly than those crossing by simple diffusion.

Question 163 out of 3 points

What is active transport?

Selected Answer:

movement of molecules into or out of a cell against a concentration gradient

Answers: diffusion of molecules within a cell

movement of molecules into or out of a cell against a concentration gradient

movement of molecules into or out of a cell down a concentration gradient

movement of molecules into or out of a cell using special proteins and not requiring an expenditure of energy

rapid movement of molecules in a solution

Question 170 out of 3 points

Some of the most important molecules that are embedded within the bilayer membrane of a cell, such as the molecules that allow for transport and cell recognition, are:

Selected Answer:

phospholipases.

Answers: steroids.

glycoproteins.

nucleic acids.

phospholipases.

Question 183 out of 3 points

In general, which of the following is largely responsible for moving substances across the plasma membrane, communicating with other cells, and identifying the cell?

Selected Answer:

proteins

Answers: phospholipids

carbohydrates

proteins

nucleic acids

cytoskeleton

Question 193 out of 3 points

The secretion of excess water via the contractive vacuole of a  Paramecium cell is an example of:

Selected Answer:

exocytosis.

Answers: facilitated diffusion.

active transport.

osmosis.

exocytosis.

simple diffusion.

Question 203 out of 3 points

The main lipids found in cell membranes are:

Selected Answer:

phospholipids.

Answers: steroids.

triglycerides.

phospholipids.

glycerol.

waxes.

Question 213 out of 3 points

Within the fluid mosaic of a plasma membrane, what is the role of transport and channel proteins?

Selected Answer:

They permit salts and sugars to move through the plasma membrane.

Answers: They prevent the passage of amino acids.

They permit salts and sugars to move through the plasma membrane.

They may set off cellular changes such as cell division or hormone secretion.

They are cell-surface attachment sites.

They identify the cell.

Question 223 out of 3 points

In reference to diffusion, "passive" really means:

Selected Answer:

no energy required.

Answers: without a membrane.

in the air.

no gradient.

very slowly.

no energy required.

Question 233 out of 3 points

Which of the following accounts for the fluid aspect of the fluid mosaic model of plasma membranes?

Selected Answer:

The individual phospholipid molecules are not bonded to one another, so the movement of certain proteins and lipids is possible within the bilayer.

Answers: The individual phospholipid molecules are not bonded to one another, so the movement of certain proteins and lipids is possible within the bilayer.

The plasma membrane is "fluid" because of the movement of substances across the membrane.

The bilayer permits diffusion of certain lipid-soluble

substances.

The membrane is water soluble.

One of the components of the membrane is water.

Question 243 out of 3 points

Which of the following types of membrane proteins are responsible for facilitated diffusion?

Selected Answer:

transport proteins

Answers: transport proteins

recognition proteins

enzymes

receptor proteins

attachment proteins

Question 253 out of 3 points

The slowest rate of diffusion of dye particles in water will occur at:

Selected Answer:

10°C.

Answers: 10°C.

20°C.

30°C.

60°C.

Question 263 out of 3 points

Two aqueous solutions are separated by a selectively permeable membrane that allows water to pass through but does not allow starch to pass through. Solution A is 10% starch and solution B is 5%

starch. What will occur?

Selected Answer:

Water will diffuse from solution B to solution A.

Answers: Water will diffuse from solution A to solution B.

Water will diffuse from solution B to solution A.

Starch will diffuse from solution A to solution B.

Starch will diffuse from solution B to solution A.

Both water and starch will diffuse from solution B to solution A.

Question 273 out of 3 points

What happens when diffusion moves molecules across the plasma membrane?

Selected Answer:

The process is relatively slow and is driven by concentration gradients.

Answers: The cell gains needed materials and gets rid of excess materials very quickly.

Most molecules are capable of crossing the phospholipid bilayer at any location and at basically the same rate.

Energy input is required to transport molecules.

The rate of diffusion cannot be influenced by the cell.

The process is relatively slow and is driven by concentration gradients.

Question 283 out of 3 points

Molecules assisted by carrier proteins may cross a selectively permeable membrane by:

Selected Answer:

facilitated diffusion.

Answers: facilitated diffusion.

active transport.

osmosis.

endocytosis.

simple diffusion.

Question 293 out of 3 points

Cells use exocytosis to:

Selected Answer:

release substances from the cell.

Answers: move away from danger.

release substances from the cell.

ingest nutrients.

pump hydrogen molecules across the membrane.

create new cells.

Question 303 out of 3 points

The cytoplasm of a certain cell, such as a neuron, already has a high concentration of K + ions. How can K + ions continue to enter the cell?

Selected Answer:

active transport

Answers: active transport

facilitated diffusion

osmosis

endocytosis

infusion

Question 310 out of 3 points

The movement of molecules across a cell membrane in which no energy is required (i.e., diffusion) is called ________ transport, and the movement of molecules across a cell membrane in which energy (i.e., ATP) is required is called ________ transport.

Selected Answer:

passive

Question 323 out of 3 points

The major lipids in biological membranes are called ________.

Selected Answer:

phospholipids

Question 333.5 out of 3.5 points

The phospholipid contains two different parts: a ____[a]_____ head and a pair of ____[b]____ tails.Specified Answer for: a

hydrophilic

Specified Answer for: b

hydrophobic

Question 343.5 out of 3.5 points

Communication between cells occurs via ____[a]____ in plant cells and via ____[b]____ (two words) in animal cells.Specified Answer for: a

plasmodesmata

Specified Answer for: b

gap junctions

Question 353.5 out of 3.5 points

A membrane that is permeable to some substances but not to others is described as being _______[a]________ (two words).  The movement of a substance through a membrane down its concentration gradient

is called _______[b]________.  When applied to water, this process is called _______[c]________.  Channels that are specific for water are called ______[d]_________.  The process that moves substances through a membrane against their concentration gradient is called _______[e]________ (two words).Specified Answer for: a

selectively permeable

Specified Answer for: b

diffusion

Specified Answer for: c

osmosis

Specified Answer for: d

aquaporins

Specified Answer for: e

active transport

Question 13 out of 3 points

Adhesion of cells within animal tissues is accomplished by cell-to-cell junctions called:

Selected Answer:

desmosomes.

Answers: desmosomes.

tight junctions.

gap junctions.

plasmodesmata.

cell plates.

Question 23 out of 3 points

Active transport requires all of the following EXCEPT:

Selected Answer:

aquaporins.

Answers: transport proteins.

ATP.

a membrane.

a gradient.

aquaporins.

Question 33 out of 3 points

Some of the most important molecules that are embedded within the bilayer membrane of a cell, such as the molecules that allow for transport and cell recognition, are:

Selected Answer:

glycoproteins.

Answers: steroids.

glycoproteins.

nucleic acids.

phospholipases.

Question 43 out of 3 points

Plasma membranes are BEST described as a:

Selected Answer:

double layer of phospholipids with hydrophobic tails oriented toward one another.

Answers: double layer of phospholipids with hydrophobic tails directed toward the cytoplasm of the cell.

single layer of phospholipids with water molecules attached along one side.

double layer of phospholipids with hydrophilic heads directed toward one another.

double layer of phospholipids with hydrophobic tails

oriented toward one another.

single layer of phospholipids with tails pointed toward the inside of the cell.

Question 50 out of 3 points

The diffusion of water molecules across a selectively permeable membrane is called:

Selected Answer:

facilitated diffusion.

Answers: facilitated diffusion.

hydrolysis.

active transport.

exocytosis.

osmosis.

Question 63 out of 3 points

When a mouse cell and a human cell are fused, the membrane proteins of the two cells become uniformly distributed over the surface of the hybrid cell. This occurs because:

Selected Answer:

many proteins can move around within the bilayer.

Answers: many proteins can move around within the bilayer.

all proteins are anchored within the membrane.

proteins are asymmetrically distributed within the membrane.

all proteins in the plasma membrane are extrinsic.

different membranes contain different proteins.

Question 73 out of 3 points

Specialized cell junctions include all of the following EXCEPT:

Selected Answer:

phospholipases.

Answers: gap junctions.

tight junctions.

desmosomes.

phospholipases.

Question 83 out of 3 points

Imagine an artificial cell made with a selectively permeable membrane that allows water to pass through but does not allow sugar to pass. If you fill this cell with a 1% sugar solution and then you place the cell in a 2% sugar solution, what happens?

Selected Answer:

Water leaves the cell.

Answers: Water enters the cell.

Water leaves the cell.

Water does not leave or enter the cell.

Sugar diffuses in and water diffuses out until equilibrium is reached.

Question 93 out of 3 points

Which process accounts for the movement of solids into some animal cells?

Selected Answer:

phagocytosis

Answers: active transport

facilitated diffusion

simple diffusion

osmosis

phagocytosis

Question 103 out of 3 points

The urinary bladder is protected from leaking due to cell-to-cell junctions called:

Selected Answer:

tight junctions.

Answers: desmosomes.

tight junctions.

gap junctions.

plasmodesmata.

Question 113 out of 3 points

You observe a cell under a microscope and you can clearly see a cell wall, a vacuole, and cytoplasmic connections. These cytoplasmic connections must be:

Selected Answer:

plasmodesmata.

Answers: gap junctions.

desmosomes.

plasmodesmata.

tight junctions.

osmotic channels.

Question 123 out of 3 points

Solutions that cause water to enter cells by osmosis are called:

Selected Answer:

hypotonic.

Answers: hypertonic.

isotonic.

hypotonic.

permeable.

hydrophilic.

Question 130 out of 3 points

According to the fluid mosaic model of cell membranes, which of the following is a TRUE statement about membrane phospholipids?

Selected Answer:

They have hydrophilic tails in the interior of the membrane.

Answers: They form a viscous fluid through which proteins shift and flow.

They frequently flip-flop from one side of the membrane to the other.

They occur in an uninterrupted bilayer, with membrane proteins restricted to the surface of the membrane.

They are free to depart from the membrane and are dissolved in the surrounding solution.

They have hydrophilic tails in the interior of the membrane.

Question 143 out of 3 points

What happens when diffusion moves molecules across the plasma membrane?

Selected Answer:

The process is relatively slow and is driven by concentration gradients.

Answers: The cell gains needed materials and gets rid of excess materials very quickly.

Most molecules are capable of crossing the phospholipid bilayer at any location and at basically the same rate.

Energy input is required to transport molecules.

The rate of diffusion cannot be influenced by the cell.

The process is relatively slow and is driven by concentration gradients.

Question 153 out of 3 points

Phospholipids spontaneously form a bilayer in an aqueous solution. Why do the heads of the phospholipids point out and the tails point toward one another?

Selected Answer:

The tails are repelled by the aqueous environment.

Answers: The tails are nonpolar and form hydrogen bonds with one another.

The tails are repelled by the aqueous environment.

The heads are repelled by the water inside and outside the cell.

Question 163 out of 3 points

The slowest rate of diffusion of dye particles in water will occur at:

Selected Answer:

10°C.

Answers: 10°C.

20°C.

30°C.

60°C.

Question 173 out of 3 points

Which of the following accounts for the fluid aspect of the fluid mosaic model of plasma membranes?

Selected Answer:

The individual phospholipid molecules are not bonded to one another, so the movement of certain proteins and lipids is possible within the bilayer.

Answers: The individual phospholipid molecules are not bonded to one another, so the movement of certain proteins and lipids is possible within the bilayer.

The plasma membrane is "fluid" because of the movement of substances across the membrane.

The bilayer permits diffusion of certain lipid-soluble substances.

The membrane is water soluble.

One of the components of the membrane is water.

Question 183 out of 3 points

The main lipids found in cell membranes are:

Selected Answer:

phospholipids.

Answers: steroids.

triglycerides.

phospholipids.

glycerol.

waxes.

Question 193 out of 3 points

The secretion of excess water via the contractive vacuole of a  Paramecium cell is an example of:

Selected Answer:

exocytosis.

Answers: facilitated diffusion.

active transport.

osmosis.

exocytosis.

simple diffusion.

Question 203 out of 3 points

If you forget to water your favorite plant, all of the following will occur at a cellular level EXCEPT:

Selected Answer:

turgor pressure will build up in the cell.

Answers: water will move out of the cytosol by osmosis.

water will move out of the vacuole by osmosis.

turgor pressure will build up in the cell.

the plasma membrane will shrink away from the cell wall.

osmosis will occur.

Question 213 out of 3 points

Two similar-sized animal cells are placed in a 0.5% sucrose solution. Cell A enlarges for a while and then stops; cell B continues to enlarge and finally ruptures. Which of the following must have been TRUE at the beginning of the experiment?

Selected Answer:

Cell B was hypertonic to cell A.

Answers: Cell A was hypotonic to the solution, and cell B was hypertonic.

Cell A was hypertonic to the solution, and cell B was hypotonic.

Cell A was hypertonic to cell B.

Cell B was hypertonic to cell A.

Cells A and B were isotonic to each other.

Question 223 out of 3 points

Osmosis moves water from a region of:

Selected Answer:

low concentration of dissolved material to a region of high concentration.

Answers: high concentration of dissolved material to a region of low concentration.

low concentration of dissolved material to a region of high concentration.

hypertonic solution to a region of hypotonic solution.

negative osmotic potential to a region of positive osmotic potential.

low concentration of water to a region of high concentration of water.

Question 233 out of 3 points

The rate of facilitated diffusion of a molecule across a membrane will increase as the concentration gradient of the molecule across the membrane increases to a certain point. Eventually, an increase in the concentration of the molecule will not cause any further increase in facilitated diffusion. This is because:

Selected Answer:

there are a limited number of carrier proteins in the membrane.

Answers: facilitated diffusion requires ATP energy.

as the concentration gradient increases, molecules interfere with one another.

there are a limited number of carrier proteins in the membrane.

the increased concentration gradient causes a situation far from equilibrium.

the diffusion constant depends on the concentration gradient.

Question 243 out of 3 points

For diffusion to occur, there must be:

Selected Answer:

a gradient.

Answers: a membrane.

a gradient.

water.

ATP.

Question 253 out of 3 points

The bacterium  Vibrio cholerae releases a toxin that blocks a channel protein in the membranes of cells that line the intestine. This toxin prevents the movement of positively charged sodium ions out of the intestine and into these cells. If the sodium ions could not move into the cells, how would this affect the movement of water?

Selected Answer:

Water would leave the cells and enter the intestines by osmosis.

Answers: Water would leave the intestines and enter the cells by diffusion.

Water would leave the intestines and enter the cells

by osmosis.

Water would leave the cells and enter the intestines by diffusion.

Water would leave the cells and enter the intestines by osmosis.

The movement of water would not be affected.

Question 263 out of 3 points

All of the following may influence the rate of simple diffusion across a selectively permeable membrane EXCEPT the:

Selected Answer:

size of the cell.

Answers: size of the molecule.

lipid solubility of the molecule.

concentration gradient.

ambient (air) temperature.

size of the cell.

Question 273 out of 3 points

Which of the following is an energy-requiring mode of transport that brings substances into a cell?

Selected Answer:

receptor-mediated endocytosis

Answers: facilitated diffusion

osmosis

receptor-mediated endocytosis

simple diffusion

Question 28

3 out of 3 pointsThe hydrophobic tails of a phospholipid bilayer are oriented toward the:

Selected Answer:

interior of the plasma membrane (i.e., toward one another).

Answers: interior of the plasma membrane (i.e., toward one another).

extracellular fluid surrounding the cell.

cytoplasm of the cell.

Question 293 out of 3 points

The blood plasma of a man who drinks saltwater will become ________ to his red blood cells, whereas the red blood cells will be ________ to the blood plasma.

Selected Answer:

hypertonic; hypotonic

Answers: isotonic; isotonic

hypertonic; isotonic

hypotonic; hypertonic

hypertonic; hypotonic

isotonic; hypertonic

Question 303 out of 3 points

In biological membranes, the phospholipids are arranged in a:

Selected Answer:

bilayer with the fatty acids pointing toward one another.

Answers: bilayer with the fatty acids pointing toward one another.

bilayer with the fatty acids facing outward.

single layer with the fatty acids facing the interior of the cell.

single layer with the phosphorus-containing region facing the interior of the cell.

bilayer with the phosphorus groups in the interior of the membrane.

Question 313 out of 3 points

________ is used by cells to consume large particles such as bacteria.

Selected Answer:

Phagocytosis

Question 320 out of 3 points

The movement of molecules across a cell membrane in which no energy is required (i.e., diffusion) is called ________ transport, and the movement of molecules across a cell membrane in which energy (i.e., ATP) is required is called ________ transport.

Selected Answer:

active

Question 333.5 out of 3.5 points

A membrane that is permeable to some substances but not to others is described as being _______[a]________ (two words).  The movement of a substance through a membrane down its concentration gradient is called _______[b]________.  When applied to water, this process is called _______[c]________.  Channels that are specific for water are called ______[d]_________.  The process that moves substances through a membrane against their concentration gradient is called _______[e]________ (two words).Specified Answer for: a

selectively permeable

Specified Answer for: b

diffusion

Specified Answer for: c

osmosis

Specified Answer for: d

aquaporins

Specified Answer for: e

active transport

Question 342.1 out of 3.5 points

The general process by which fluids or particles are transported into cells is called _______[a]________.   Does this process require energy? _______[b]________ The specific term for engulfing fluid is_______[c]________ , and the term for engulfing particles is _______[d]________.  The engulfed substances are taken into the cell in membrane enclosed sacs called _______[e]________.Specified Answer for: a

endocytosis

Specified Answer for: b

requires energy

Specified Answer for: c

Pinocytosis

Specified Answer for: d

Phagocytosis

Specified Answer for: e

Endocytosis

Question 353.5 out of 3.5 points

After each molecule, place the two-word term that most specifically describes the process by which it moves through a plasma membrane: Carbon dioxide:  _______[a]________ ; ethyl alcohol: ·______[b]_________ ; a sodium ion: _______[c]________ ;·glucose: _______[d]________.Specified Answer for: a

simple diffusion

Specified Answer for: b

simple diffusion

Specified Answer for: c

facilitated diffusion

Specified Answer for: d

facilitated diffusion

CHAPTER 6

Question 12.9 out of 2.9 points

Which of the following lowers the activation energy of a biochemical reaction?

Selected Answer:

catalysts

Answers: catalysts

high temperature

low concentration of reactants

altering pH to 7

high concentration of products

Question 22.9 out of 2.9 points

The BEST description of a coupled reaction is:

Selected Answer:

two reactions that involve one providing energy for the other.

Answers: two reactions that occur simultaneously.

a reaction that occurs right after another reaction.

two reactions that occur in the same organelle.

reactions that occur during sexual reproduction.

two reactions that involve one providing energy for the other.

Question 32.9 out of 2.9 points

Which statement BEST describes the relationship between an enzyme and a reactant?

Selected Answer:

The relationship is temporary.

Answers: The relationship is temporary.

Covalent chemical bonds stabilize the relationship.

The enzyme and the reactant molecule are both permanently changed.

The resultant product and the enzyme are permanently bonded together.

The reactant cannot function without the enzyme.

Question 42.9 out of 2.9 points

In the liver, the polysaccharide glycogen is broken down into glucose monomers. The glucose molecules are then released into the blood when blood sugar levels need to be raised. This process is an example of a(n) ________ reaction.

Selected Answer:

exergonic

Answers: endergonic

exergonic

kinetic

potential

Question 52.9 out of 2.9 points

How is it possible for living organisms to comply with the second law of thermodynamics?

Selected Answer:

Sunlight functions as an ultimate source of energy for most forms of life on Earth.

Answers: Chemical reactions inside cells mostly cause an increase in high-level energy.

Living organisms are totally isolated systems that are not subject to the laws of physics.

Sunlight functions as an ultimate source of energy for most forms of life on Earth.

Living organisms are unique in that they do not require energy for survival.

Organisms are able to function efficiently on heat energy alone.

Question 60 out of 2.9 points

Which of the following will bind to the active site of an enzyme?

Selected Answer:

substrate only

Answers: substrate only

competitive inhibitor only

allosteric inhibitor only

noncompetitive inhibitor only

both substrate and competitive inhibitor

Question 72.9 out of 2.9 points

Certain vitamins, such as niacin, act as _______ in enzyme-catalyzed reactions.

Selected Answer:

coenzymes

Answers: substrates

allosteric activators

coenzymes

inhibitors

catalysts

Question 82.9 out of 2.9 points

When a high-energy bond of ATP is broken, primarily what happens to the released energy?

Selected Answer:

It drives endergonic reactions in the cell.

Answers: It is lost as light energy.

It functions as a second messenger.

It polarizes the cell.

It converts inorganic phosphates to energy carrier molecules.

It drives endergonic reactions in the cell.

Question 92.9 out of 2.9 points

The end product of a biosynthetic pathway often acts to block the initial step in that pathway. This phenomenon is called:

Selected Answer:

feedback inhibition.

Answers: allosteric activation.

denaturation.

irreversible inhibition.

feedback inhibition.

substrate activation.

Question 102.9 out of 2.9 points

Enzymes are important because they:

Selected Answer:

allow reactions to occur at body temperature.

Answers: are structural proteins that make up bodily tissues.

can enable organisms to evade the laws of thermodynamics.

bind irreversibly to substrates.

allow reactions to occur at body temperature.

increase the body temperature of organisms.

Question 112.9 out of 2.9 points

Which of the following does not have much potential energy?

Selected Answer:

a ball that has rolled downhill and stopped

Answers: a water droplet at the top of a waterfall

a glucose molecule

a diver on a springboard

a 9-V battery

a ball that has rolled downhill and stopped

Question 122.9 out of 2.9 points

FAD is an example of:

Selected Answer:

an electron carrier.

Answers: a protein.

an electron carrier.

an enzyme.

an enzymesubstrate complex.

an active site.

Question 132.9 out of 2.9 points

Most reactions in the body occur too slowly to sustain life. This is because:

Selected Answer:

many reactions require large inputs of activation energy.

Answers: all reactions in the body are endergonic.

many reactions require large inputs of activation energy.

no catalysts are present in body cells.

most biological catalysts are not active at body temperature (37°C).

there is not enough ATP in body cells.

Question 142.9 out of 2.9 points

Which of the following is the organic molecule that is sometimes required for certain enzyme activity?

Selected Answer:

a coenzyme

Answers: an accessory enzyme

an allosteric enzyme

a coenzyme

a functional group

an activator

Question 152.9 out of 2.9 points

Imagine you are conducting an experiment on a yeast enzyme known as sucrase. This enzyme is used by yeast cells to break down sucrose into glucose and fructose. What type of reaction is this?

Selected Answer:

exergonic

Answers: metergonic

exergonic

endergonic

spontaneous

Question 162.9 out of 2.9 points

All of the following statements are true of the first law of thermodynamics EXCEPT:

Selected Answer:

the amount of useful energy decreases.

Answers: the amount of useful energy decreases.

the first law of thermodynamics is often called the law of the conservation of energy.

the total amount of energy within an isolated system remains the same.

one form of energy may be converted to a different form of energy.

Question 172.9 out of 2.9 points

The most common energy carrier molecule in living organisms is:

Selected Answer:

ATP.

Answers: ATP.

inorganic phosphate.

DNA.

glucose.

NADPH.

Question 182.9 out of 2.9 points

Why is photosynthesis a coupled reaction?

Selected Answer:

An exergonic reaction occurs in the sun, and an endergonic reaction occurs in the plant.

Answers: The exergonic reaction occurs in the plant, and the endergonic reaction occurs in the soil.

The exergonic reaction occurs in the plant, and the endergonic reaction occurs in the sun.

Photosynthesis requires a couple of reactants: carbon dioxide and water.

An exergonic reaction occurs in the sun, and an endergonic reaction occurs in the plant.

Sunlight energy enters a plant and is ultimately lost as heat.

Question 192.9 out of 2.9 points

Sulfa antibiotics damage bacteria by affecting a certain bacterial enzyme. The sulfa antibiotic looks similar to a substrate normally required by the bacterial cells to live. The sulfa antibiotic occupies the active site of the required enzyme and blocks entry of its normal substrate. This prevents the bacteria from making nucleotides that are required for their reproduction and survival. Based on this

information, the action of sulfa antibiotics is an example of:

Selected Answer:

competitive inhibition.

Answers: electron carriers.

competitive inhibition.

denaturing of proteins.

activation energy.

Question 202.9 out of 2.9 points

During photosynthesis, plants convert light energy to chemical energy. This is an example of:

Selected Answer:

the first law of thermodynamics.

Answers: increasing entropy.

chemical equilibrium.

the first law of thermodynamics.

the second law of thermodynamics.

a spontaneous reaction.

Question 212.9 out of 2.9 points

How is your body able to counteract the effects of entropy?

Selected Answer:

eating a balanced diet

Answers: regular exercise

sunbathing

eating a balanced diet

bathing regularly

buffers

Question 222.9 out of 2.9 points

Competitive and noncompetitive enzyme inhibitors differ with respect to:

Selected Answer:

the precise location on the enzyme to which they bind.

Answers: the precise location on the enzyme to which they bind.

their pH.

their binding affinities.

their energies of activation.

Question 232.9 out of 2.9 points

Preservatives such as citric acid are added to foods to interfere with bacterial growth. This creates an acidic pH in the food. Why does this affect the bacteria that are present?

Selected Answer:

An acidic environment causes bacterial enzymes to fail or work less efficiently.

Answers: An acidic environment encourages endergonic reactions in the bacterial cells.

An acidic environment increases the activation energy more quickly in bacteria.

An acidic environment causes bacterial enzymes to fail or work less efficiently.

An acidic environment causes the bacteria to grow more rapidly.

Question 242.9 out of 2.9 points

What is the ultimate source of energy for almost all forms of life on Earth?

Selected Answer:

solar energy

Answers: heat energy

solar energy

thermal energy

chemical energy

nuclear energy

Question 250 out of 2.9 points

Which of the following is NOT a common energy carrier in the cell?

Selected Answer:

phosphate

Answers: ADP

phosphate

electron carriers

ATP

Question 262.9 out of 2.9 points

The addition of the competitive inhibitor slows down a particular reaction. How could you overcome the effects of the inhibitor and increase the rate of the reaction?

Selected Answer:

add more substrate

Answers: add more inhibitor

add more substrate

lower the temperature of the reaction

add a coenzyme

allow the reaction to reach equilibrium

Question 272.9 out of 2.9 points

Which of the following functions as a biological catalyst?

Selected Answer:

enzyme

Answers: energy carrier molecule

amino acid

enzyme

substrate

steroid

Question 282.9 out of 2.9 points

Animals have enzymes that break apart starch molecules but not cellulose, despite the fact that both are made up of glucose subunits. Which enzyme characteristic BEST explains this?

Selected Answer:

Enzymes are highly specific.

Answers: Enzyme activity is regulated.

Enzymes usually speed up chemical reactions.

Enzymes are not permanently changed by the reactions they promote.

Enzymes are highly specific.

All enzymes are proteins.

Question 292.9 out of 2.9 points

The second law of thermodynamics states that the ________, or disorder, of the universe is constantly increasing.

Selected Answer:

ENTROPY

Question 302.9 out of 2.9 points

The molecule ________ is the major energy carrier in cells.

Selected Answer:

ATP

Question 312.9 out of 2.9 points

Sitting at the top of a slide, a child has ________ energy; sliding down, she is using ________ energy.

Selected Answer:

POTENTIAL; KINETIC

Question 320 out of 2.9 points

Special molecules such as NAD + and FAD transport ________ in cells, which can then be used as energy in the cell.

Selected Answer:

cellular respiration

Question 330 out of 4 points

The burning of sugars as fuels for runners is an example of an _____[a]_____ chemical reaction, whereas the production of sugars during photosynthesis is an example of an ____[b]______ chemical reaction.Specified Answer for: a

endergonic

Specified Answer for: b

exergonic

Question 345 out of 5 points

According to the first law of thermodynamics, energy can be neither _____[a]______ nor

_____[b]______.  Energy occurs in two major forms:  _____[c]______ the energy of movement, and _____[d]______ or stored energy.Specified Answer for: a

created

Specified Answer for: b

destroyed

Specified Answer for: c

Kinetic

Specified Answer for: d

Potential

Question 355 out of 5 points

The abbreviation ATP stands for _____[a]______ (two words).  This molecule is the principal _____[b]______ (two words) molecule in living cells. The molecule is synthesized by cells from _____[c]______ and _____[d]______. This synthesis requires an input of _____[e]______ which is temporarily stored in the ATP molecule.Specified Answer for: a

Adenosine triphosphate

Specified Answer for: b

energy carrier

Specified Answer for: c

adensoine diphosphate

Specified Answer for: d

phosphate

Specified Answer for: e

energy

Question 1

2.9 out of 2.9 pointsCompetitive and noncompetitive enzyme inhibitors differ with respect to:

Selected Answer:

the precise location on the enzyme to which they bind.

Answers: the precise location on the enzyme to which they bind.

their pH.

their binding affinities.

their energies of activation.

Question 22.9 out of 2.9 points

The optimum reaction rate of a particular enzyme occurs at pH 7.3 at 37°C. This reaction would probably proceed faster by:

Selected Answer:

increasing the temperature to 38°C and keeping the pH at 7.3.

Answers: decreasing the pH and increasing the temperature.

increasing the temperature to 38°C and keeping the pH at 7.3.

increasing the pH and maintaining the temperature at 37°C.

increasing both temperature and pH.

Question 32.9 out of 2.9 points

Which of the following will bind to the active site of an enzyme?

Selected Answer:

both substrate and competitive inhibitor

Answers: substrate only

competitive inhibitor only

allosteric inhibitor only

noncompetitive inhibitor only

both substrate and competitive inhibitor

Question 42.9 out of 2.9 points

When solid sodium hydroxide is added to water, the solution gets hot. This is an example of:

Selected Answer:

an exergonic process.

Answers: an endergonic process.

an exergonic process.

an enzyme-catalyzed process.

a release of activation energy.

a conversion of kinetic energy to potential energy.

Question 52.9 out of 2.9 points

Which of the following is the organic molecule that is sometimes required for certain enzyme activity?

Selected Answer:

a coenzyme

Answers: an accessory enzyme

an allosteric enzyme

a coenzyme

a functional group

an activator

Question 62.9 out of 2.9 points

Enzymes are important because they:

Selected Answer:

allow reactions to occur at body temperature.

Answers: are structural proteins that make up bodily tissues.

can enable organisms to evade the laws of thermodynamics.

bind irreversibly to substrates.

allow reactions to occur at body temperature.

increase the body temperature of organisms.

Question 72.9 out of 2.9 points

All of the following statements pertaining to catalysts are true EXCEPT:

Selected Answer:

catalysts increase activation energy requirements.

Answers: biological catalysts are specific enzymes.

catalysts increase activation energy requirements.

catalysts increase the reaction rate.

catalysts are not permanently altered during reaction.

catalysts can be used over and over again.

Question 82.9 out of 2.9 points

The hydrolysis of sucrose to glucose and fructose is a spontaneous reaction. However, if you dissolve sucrose in water and keep the solution overnight at room temperature, there is no detectable conversion to glucose and fructose. Why not?

Selected Answer:

The reaction requires a catalyst.

Answers: The reaction is at equilibrium.

The energy of the products is higher than the energy of the reactants.

The activation energy of the reaction decreases.

The reaction is endergonic.

The reaction requires a catalyst.

Question 92.9 out of 2.9 points

Place these steps of enzyme catalysis in the correct order:1. The substrate and enzyme change shape.2. The substrate enters the active site.3. The enzyme reverts to its original configuration.4. The product is expelled.

Selected Answer:

2, 1, 4, 3

Answers: 1, 2, 3, 4

1, 3, 4, 2

2, 1, 4, 3

2, 1, 3, 4

2, 3, 1, 4

Question 102.9 out of 2.9 points

Which of the following is part of the first law of thermodynamics?

Selected Answer:

Energy cannot be created or destroyed.

Answers: Energy cannot be created or destroyed.

Kinetic energy is stored energy.

Energy cannot be transferred or transformed.

Exergonic reactions are coupled with endergonic reactions.

Potential energy equals kinetic energy in a reaction.

Question 112.9 out of 2.9 points

Preservatives such as citric acid are added to foods to interfere with bacterial growth. This creates an acidic pH in the food. Why does this affect the bacteria that are present?

Selected Answer:

An acidic environment causes bacterial enzymes to fail or work less efficiently.

Answers: An acidic environment encourages endergonic reactions in the bacterial cells.

An acidic environment increases the activation energy more quickly in bacteria.

An acidic environment causes bacterial enzymes to fail or work less efficiently.

An acidic environment causes the bacteria to grow more rapidly.

Question 122.9 out of 2.9 points

When a high-energy bond of ATP is broken, primarily what happens to the released energy?

Selected Answer:

It drives endergonic reactions in the cell.

Answers: It is lost as light energy.

It functions as a second messenger.

It polarizes the cell.

It converts inorganic phosphates to energy carrier molecules.

It drives endergonic reactions in the cell.

Question 132.9 out of 2.9 points

How is your body able to counteract the effects of entropy?

Selected Answer:

eating a balanced diet

Answers: regular exercise

sunbathing

eating a balanced diet

bathing regularly

buffers

Question 142.9 out of 2.9 points

Activation energy is necessary for all ________ reactions.

Selected Answer:

chemical

Answers: exergonic

endergonic

coupled

chemical

Question 152.9 out of 2.9 points

Each of the following requires 12 carbon atoms. Which of the arrangements of carbon atoms has the greatest entropy?

Selected Answer:

12 molecules of carbon dioxide, CO 2

Answers: 12 molecules of carbon dioxide, CO2

one molecule of the disaccharide maltose, C12H22O11

two molecules of the monosaccharide glucose, C6H12O6

four molecules of the monosaccharide pyruvate, C3H4O3

Question 162.9 out of 2.9 points

Imagine you are conducting an experiment on a yeast enzyme known as sucrase. This enzyme is used by yeast cells to break down sucrose into glucose and fructose. What type of reaction is this?

Selected Answer:

exergonic

Answers: metergonic

exergonic

endergonic

spontaneous

Question 172.9 out of 2.9 points

When-if ever-do molecules stop moving?

Selected Answer:

at absolute zero (-273.15°C)

Answers: at the freezing point (0°C)

at the boiling point (100°C)

at absolute zero (-273.15°C)

never

Question 182.9 out of 2.9 points

In an isolated system, all of the following are true of the second law of thermodynamics EXCEPT:

Selected all chemical reactions release more energy than they consume.

Answer:

Answers: the amount of useful energy decreases.

spontaneous changes result in a more uniform distribution of energy.

all chemical reactions release more energy than they consume.

there is a natural tendency toward greater disorder of the organization of matter.

Question 192.9 out of 2.9 points

Why is photosynthesis a coupled reaction?

Selected Answer:

An exergonic reaction occurs in the sun, and an endergonic reaction occurs in the plant.

Answers: The exergonic reaction occurs in the plant, and the endergonic reaction occurs in the soil.

The exergonic reaction occurs in the plant, and the endergonic reaction occurs in the sun.

Photosynthesis requires a couple of reactants: carbon dioxide and water.

An exergonic reaction occurs in the sun, and an endergonic reaction occurs in the plant.

Sunlight energy enters a plant and is ultimately lost as heat.

Question 202.9 out of 2.9 points

Similar to a car, a human body is about ________ efficient in converting chemical energy to movement.

Selected Answer:

25%

Answers: 1%

25%

75%

95%

Question 212.9 out of 2.9 points

Which molecule functions in the short-term storage of energy?

Selected Answer:

adenosine triphosphate

Answers: glycogen

fat

sucrose

adenosine triphosphate

protein

Question 222.9 out of 2.9 points

During photosynthesis, plants convert light energy to chemical energy. This is an example of:

Selected Answer:

the first law of thermodynamics.

Answers: increasing entropy.

chemical equilibrium.

the first law of thermodynamics.

the second law of thermodynamics.

a spontaneous reaction.

Question 232.9 out of 2.9 points

Sulfa antibiotics damage bacteria by affecting a certain bacterial enzyme. The sulfa antibiotic looks similar to a substrate normally required by the bacterial cells to live. The sulfa antibiotic occupies the active site of the required enzyme and blocks entry of its normal substrate. This prevents the bacteria from making nucleotides that are required for their reproduction and survival. Based on this information, the action of sulfa antibiotics is an example of:

Selected Answer:

competitive inhibition.

Answers: electron carriers.

competitive inhibition.

denaturing of proteins.

activation energy.

Question 242.9 out of 2.9 points

All of the following statements are true of the first law of thermodynamics EXCEPT:

Selected Answer:

the amount of useful energy decreases.

Answers: the amount of useful energy decreases.

the first law of thermodynamics is often called the law of the conservation of energy.

the total amount of energy within an isolated system remains the same.

one form of energy may be converted to a different form of energy.

Question 252.9 out of 2.9 points

The reactant in an enzyme-catalyzed reaction is the:

Selected Answer:

substrate.

Answers: substrate.

active site.

product.

inhibitor.

activation energy.

Question 262.9 out of 2.9 points

A "high-energy" bond in an ATP molecule is located between:

Selected Answer:

two phosphate groups.

Answers: adenine and ribose.

two phosphate groups.

ribose and the first phosphate group.

adenine and the first phosphate group.

Question 272.9 out of 2.9 points

Animals have enzymes that break apart starch molecules but not cellulose, despite the fact that both are made up of glucose subunits. Which enzyme characteristic BEST explains this?

Selected Answer:

Enzymes are highly specific.

Answers: Enzyme activity is regulated.

Enzymes usually speed up chemical reactions.

Enzymes are not permanently changed by the reactions they promote.

Enzymes are highly specific.

All enzymes are proteins.

Question 282.9 out of 2.9 points

Which of the following functions as a biological catalyst?

Selected Answer:

enzyme

Answers: energy carrier molecule

amino acid

enzyme

substrate

steroid

Question 292.9 out of 2.9 points

The enzyme phosphoglucoisomerase catalyzes the conversion of glucose-6-phosphate to fructose-6-phosphate. The region on phosphoglucoisomerase where glucose-6-phosphate binds is called the ________.

Selected Answer:

Active site

Question 300 out of 2.9 points

Special molecules such as NAD + and FAD transport ________ in cells, which can then be used as energy in the cell.

Selected Answer:

electron

Question 312.9 out of 2.9 points

Sitting at the top of a slide, a child has ________ energy; sliding down, she is using ________ energy.

Selected Answer:

POTENTIAL; KINETIC

Question 322.9 out of 2.9 points

The energy of movement is referred to as ________ energy, and stored energy is referred to as ________ energy.

Selected Answer:

KINETIC; POTENTIAL

Question 334 out of 4 points

ATP is considered a short-term form of energy for the cell, whereas ____[a]______ or _____[b]_____ represent more stable, long-term energy stores.Specified Answer for: a

carbohydrates

Specified Answer for: b

fats

Question 345 out of 5 points

According to the first law of thermodynamics, energy can be neither _____[a]______ nor _____[b]______.  Energy occurs in two major forms:  _____[c]______ the energy of movement, and _____[d]______ or stored energy.Specified Answer for: a

created

Specified Answer for: b

destroyed

Specified Answer for: c

Kinetic

Specified Answer for: d

Potential

Question 355 out of 5 points

Once started, some reactions release energy and are called _____[a]______ reactions. Others require a net input of energy and are called _____[b]______ reactions.

Which type of reaction will continue spontaneously once it starts? _____[c]______.  Which type of reaction allows the formation of complex biological molecules from simpler molecules (for example, proteins from amino acids)? _____[d]______.  When the energy released from one reaction provides the energy required by another, the two reactions are described as _____[e]______ reactions. Specified Answer for: a

exergonic

Specified Answer for: b

endergonic

Specified Answer for: c

exergonic

Specified Answer for: d

endergonic

Specified Answer for: e

Coupled reactions