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Mrs. Jackson’s Absolute Bare Minimum Module 1 Review
Quarterly Assessment 1 Review
– All need energy for metabolism.• Metabolism: All of the chemical processes in an organism that build up or break down materials.
• An organism is any individual living thing.
• Living things share some common characteristics:
– All are made of one or more cells.
– All respond to their environment.– Stimuli, or physical factors, include light, temperature,
and touch.– All have genetic material (DNA) that they pass on to
offspring.
OHH
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++
Life depends on hydrogen bonds in water.
• Water is a polar molecule.– Polar molecules have slightly charged regions.
– Nonpolar molecules do not have charged regions.
1. Hydrogen bonds
form between slightly positive hydrogen atoms and slightly negative atoms. (oxygen)
Atom: OxygenCharge: Slightly negative
Atom: HydrogenCharge: Slightly positive
• Hydrogen bonds are responsible for important properties of water.– High Specific Heat: water resists changes in temp.
– Provides stability of temperature for land masses surrounded by water & for the temperature of the human body, & makes it an effective cooling agent.
– Cohesion: water molecules stick to each other.– Adhesion: water molecules stick to other things.– Ice floats on water: one of the only solids to float
on its liquid form – due to arrangement of water molecules due to charged regions.
Many compounds dissolve in water.
• A solution is formed when one substance dissolves in another. A solution is a homogeneous mixture.– Solvents dissolve other substances.– Solutes dissolve in a solvent.
solution
• “Like dissolves like.”
–Polar solvents dissolve polar solutes.–Nonpolar solvents dissolve nonpolar
solutes.–Polar substances and nonpolar
substances generally remain separate.–Example: Oil (non-polar) and
water (polar)
Maintaining homeostasis*Buffer: Helps to maintain pH.
pH<7=Acid (more H+)7=Neutral>7=Base (less H+)
Speaking of homeostasis…
• Homeostasis refers to your body maintaining stable, constant internal conditions.
• This may include:– Regulation of temperature (thermoregulation)– Regulation of pH– Regulation of oxygen delivery (for cellular
respiration!)
Carbon atoms have unique bonding properties.
1. Carbon forms covalent bonds (strong bonds) with up to four other atoms, including other carbon atoms2. They can form large, complex molecules
3. Carbon can form single, double, or triple bonds4. Carbon forms isomers
– Isomers are compounds that have the same chemical formula, but different structural formulas
• Example: C4H10
• Only carbon has these 4 characteristics
Carbon atoms have unique bonding properties – Slide 2
Many carbon-based molecules are made of many small subunits bonded together.
• Monomers are the individual subunits.• Polymers are made of many monomers.
Carbohydrates
Monomer monosaccharide
Polymer disaccharide (dimer), polysaccharide
Examples Monosaccharide: glucose, fructoseDisaccharide: sucrose (table sugar)
Polysaccharide: starch & cellulose (cell wall in plants),
glycogen (in animals)
Unique - Provide a quick source of energy
Lipids
Monomer glycerol & fatty acids; polar heads & fatty acid tails
Polymer triglycerides; phospholipidsExamples Fats, oils, cholesterol, steroids, waxes,
phospholipidsUnique - Nonpolar
- Broken down to provide energy- Used to make steroid hormones (control
stress, estrogen, testosterone)- Phospholipids make up all cell
membranes - Fats and oils contain fatty acids bonded to
glycerol
LIPIDS
ProteinsMolecule Proteins
Monomer Amino acid
Polymer Polypeptide (protein)
Examples Enzymes, hemoglobin (in blood), muscle movement, collagen
Unique - 3D structure makes them active - Peptide bonds hold amino acids together- Have a side group (R) that makes each
amino acid (and therefore protein) different
- Sometimes may contain sulfur
Nucleic acidsMolecule Nucleic acids
Monomer Nucleotide (5-carbon sugar, phosphate group, & base)
Polymer Nucleic acid
Examples DNA & RNA
Unique - Order of the bases makes every living thing unique
- DNA stores genetic information- RNA builds proteins
Chemical reactions release or absorb energy.
• Activation energy is the amount of energy that needs to be absorbed to start a chemical reaction
A catalyst lowers activation energy.• Catalysts are substances that speed up chemical
reactions– Decrease activation energy– Increase reaction rate
Enzymes allow chemical reactions to occur under tightly controlled conditions.
• Enzymes are catalysts in living things.–Enzymes are needed for
almost all processes.–Most enzymes are proteins.
Disruptions in homeostasis can prevent enzymes from functioning.
• Enzymes function best in a small range of conditions.–Changes in temperature or pH
can break hydrogen bonds.•An enzyme’s function depends on its structure.
An enzyme’s structure allows only certain reactants to bind to the enzyme.
• Substrates: reactants that bind to an enzyme• Active site: area on the enzyme where substrates bind
Exothermic reactions release more energy than they absorb.
• Excess energy is released by the reaction.– Energy “exits” the reaction. (Exo = exit)
Endothermic reactions absorb more energy than they release.
• Energy is absorbed by the reaction to make up the difference.– Energy goes into the reaction. (Endo = “into”)
• The Cell Theory:–All organisms are made of
cells.–All cells come from other
cells.–The cell is the basic unit of
structure & function in living things.
All cells share certain characteristics.
• Cells tend to be microscopic.• All cells are enclosed by a
membrane.• All cells are filled with cytoplasm.• All cells have ribosomes.
There are two cell types:
• Eukaryotic cells– Have a nucleus– Have membrane-
bound organelles
• Prokaryotic cells – Do not have a nucleus
(still have DNA)– Do not have membrane-
bound organelles
Review
Eukaryotes
• Have nucleus (DNA)• Have membrane-bound
organelles• Larger size because of
organelles• More complex• Unicellular or multicellular
Prokaryotes
• No nucleus (still have DNA)• No membrane-bound
organelles• Smaller size because of lack of
organelles• Less complex• Unicellular
Organelles and Functions
See attached list!!!How does the rough ER work with the Golgi?• Rough ER packages the
proteins its ribosomes synthesize (including membrane and secretory proteins) in vesicles to ship to the Golgi Apparatus/Body for further processing, sorting and packaging.
Cell membranes are composed of two phospholipid layers.
• The cell membrane has two major functions1. Forms a boundary between inside and
outside of the cell2. Controls passage of materials in & out of cell
Phospholipid Bilayer
• Forms a double layer surrounding a cell
• Head is polar (attracted to water) and forms hydrogen bonds with water
• Tails are nonpolar (repelled by water)
Passive transport does not require energy (ATP) input from a cell.
• Molecules can move across the cell membrane through passive transport.
• Two types of passive transport:– Diffusion: movement of molecules from high to
low concentration– Osmosis: diffusion of water
Diffusion and osmosis are types of passive transport (NO ENERGY)
• Molecules diffuse down a concentration gradient.– High to low concentration
Cell Membrane Dialysis Tubing – Diffusion Lab
WHY? Starch stays in bag – too big. Iodine goes through bag - small
How do different solutions affect cells?
• There are 3 types of solutions:1. Isotonic: solution has
the same concentration of solutes as the cell.
• Water moves in and out evenly
• Cell size stays constant
How do different solutions affect cells?
• There are 3 types of solutions:2. Hypertonic: solution
has more solutes than a cell
• More water exits the cell than enters
• Cell shrivels or dies
How do different solutions affect cells?
• There are 3 types of solutions:3. Hypotonic: solution
has fewer solutes than a cell
• More water enters the cell than exits
• Cell expands or bursts
Some molecules can only diffuse through transport proteins
• Some molecules cannot easily diffuse across the membrane– Ex: glucose (needed by cell to make energy)
• Facilitated diffusion is diffusion through transport proteins
• DOES NOT USE ENERGY
Video
3.5 Active Transport, Endocytosis, & Exocytosis
• Key Concept:– Cells use energy (ATP) to transport materials that
cannot diffuse across a membrane.
Active Transport
• Drives molecules across a membrane from lower to higher concentration– Goes against the concentration gradient
TYPES OF ACTIVE TRANSPORT
• Endocytosis: Brings materials into cell (Endo=into)
• Exocytosis: Releases materials out of cell (Exo=Exit)
Sodium-Potassium Pump
• Uses a membrane protein to pump three Na+ (sodium ions) across the membrane in exchange for two K+ (potassium ions)– ATP (energy) is needed to make the protein
change its shape so that Na+ and K+ can move through it and cross the membrane
• Helps the heart contract, helps regulate blood pressure, allows neurons to respond to stimuli and send signals
4.1 How do living things get ATP?
• ATP is the energy carrier in living things – it is usable energy for the cell.
• ATP stands for Adenosine triphosphate.• Living things get ATP from breaking down carbon
based molecules. (carbohydrates & lipids)
Starch molecule
Glucose molecule
This is how it works
phosphate removed
4.2 & 4.3 Photosynthesis
• The process of photosynthesis captures energy from sunlight and converts it into sugar (glucose).
• This process happens in organisms called autotrophs or producers. (Need to make their own food)
• This process takes place in and organelle called the chloroplast.
• The chloroplast has a green pigment in it called chlorophyll that is responsible for capturing the light energy.
So how does photosynthesis work?
The first stage of photosynthesis is called the Light Dependent Stage.• Light is captured by the chlorophyll in the
thylakoid.
So how does photosynthesis work?
The second stage of photosynthesis is called the Light Independent Stage/ Calvin Cycle/ Dark Cycle.• This process takes place in the stroma.
The chemical formula for photosynthesis
• 6CO2 + 6H2O + light C6H12O6 + 6O2
(reactants)
(products)
Carbon dioxide plus water plus light yields Glucose and oxygen
Purpose of Cellular Respiration
• To make ATP from the energy stored in glucose– Glucose comes from an organism doing
photosynthesis themselves or from eating foods containing glucose
–Remember: the purpose of photosynthesis was just to get glucose
Glycolysis• Takes place in cytoplasm (eukaryotes and prokaryotes do
this step since all cells have cytoplasm)• Splits one glucose molecule into two pyruvate molecules
–Costs the cell 2 ATP molecules to do this• 4 ATP molecules are produced (only gain 2 ATP)• This portion of CR does NOT require oxygen (anaerobic)
Kreb’s Cycle (Citric Acid Cycle)• Takes place in matrix of mitochondria (only
in eukaryotes)• 2 pyruvate (made during glycolysis) enter the mitochondrion• Each pyruvate is broken down to create 1 ATP• Total products of Kreb’s cycle (because of 2 pyruvates):
– 2 ATP
Electron Transport Chain (ETC)
• Takes place in inner membrane of mitochondria (cristae)– Folded to create more surface area for reactions to
produce more ATP in a small space• Oxygen and hydrogen ions combine to form water (released as
a waste product)• 32 ATP are made
ATP from Cellular Respiration
• 4 from Glycolysis (uses up 2, so really only gain 2 ATP)• 2 ATP from Kreb’s cycle• 32 ATP from ETC• GAIN 36 ATP from one glucose molecule
Equation for Cellular Respiration
C6H12O6 + 6O2 6CO2 + 6H2O + 36ATPLike the reverse of photosynthesis
Energy transfers:Photo: LightCPE CR: CPECPE
What happens when there’s no/not enough oxygen or there are no mitochondria?
• Answer: Fermentation–Two Kinds:
• Lactic Acid Fermentation• Alcoholic Fermentation
• Allows glycolysis to continue making ATP without oxygen