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Biochemistry
The study of life All organisms share certain properties.
Cellular organization
Homeostasis
Metabolism
Responsiveness
Reproduction
Heredity
Growth
All organisms do these things at some point during their life.
Cellular Organization A cell is a highly organized, tiny structure that is
enclosed in a thin covering called a membrane.
The cell is the basic structure of all living things.
Homeostasis The maintenance of stable internal conditions in
spite of changes in the external environment is
called homeostasis.
All living organisms must maintain a stable internal
environment.
Metabolism Metabolism is the sum of all of the chemical
reactions carried out in an organism.
What provides the energy for life on earth?
The sun
Responsiveness Plants and animals must be responsive to their
environment to cope with changes that occur.
The natural world is very difficult and dangerous.
Organisms must be willing to respond to changes
that occur.
Reproduction Because no organism lives forever, reproduction is
an essential part of life.
The goal of all organisms is to reproduce!
Those organisms that have the ability to survive and
reproduce avoid extinction.
Heredity When an organism reproduces, it passes on its own
traits to its offspring.
Heredity is the reason that children tend to look
similar to their parents.
Growth All living organisms grow.
Some grow for only a short period of time, but other
organisms grow for thousands of years.
Are viruses such as swine flu
and HIV living things? Cell theory:
All living things are made
up of cells.
Cells are the basic unit of
all life.
Each cell has a specific job.
All cells come from existing
cells!
Requirements to be
considered living:
Cellular organization
Homeostasis
Metabolism
Responsiveness
Reproduction
Heredity
Growth
So are viruses alive? So, are viruses alive: NO
A Virus is not made of cells, so they are not living
organisms!
Viruses require other cells (like YOURS) for survival.
Viruses At this point in time, viruses are still considered to be
non-living (different from dead – these things have
never been nor ever will be living). For the
purposes of this class, viruses are non-living.
This is up for change though, as the scientific
community re-defines what constitutes “living”
In the next 10 years, viruses could be considered a
living thing!!
After learning about viruses in Biology class, Sam decides to
have his cat vaccinated against feline leukemia virus.
According to cell theory, are viruses, such as feline
leukemia, considered living things?
Yes, because they can reproduce
Yes, because they are composed of cells
No, because they cannot adapt to their
environment
No, because they are not composed of cells
Ethan wants to determine whether temperature
affects the rate at which mold grows on bread. He
puts one piece of bread inside a covered petri dish
in the refrigerator. To determine whether
temperature affects the growth of mold, Ethan
should place another piece of bread into a petri
dish: Leave the dish uncovered, and place the dish in
the refrigerator
Cover the dish, and place the dish in the
refrigerator
Leave the dish uncovered, and place the dish in a
dark, room temperature cabinet
Cover the dish, and place the dish in a dark, room
temperature cabinet.
What is the best definition of a
scientific theory? An explanation of how and why a natural
phenomenon behaves the way it does
A description of an invariable relationship that
exists in nature
A speculation or guess about how nature works
An unproven fact
A little Chemistry! Matter: anything that has mass and takes up space.
To understand how living things work and interact,
you must first understand the structure of matter.
Matter is made of small particles called atoms.
Atom: the smallest unit of matter that cannot be
broken down any smaller.
Atomic Structure Atoms are made of THREE types of particles
Protons (+) positive charge
Electrons (-) negative charge
Neutrons have no charge
Protons and Neutrons make up the core (nucleus) of
the atom, while electrons move around the nucleus
in the electron cloud.
Atomic Structure and the
Periodic Table Atomic number = # of
protons
In a neutrally charged atom, the # protons = # electrons
In an ion (a charged particle), the # electrons will change More electrons than protons =
negative ion
Fewer electrons than protons = positive ion
Atomic mass number = # protons + # neutrons
Elements Elements: substance made up of atoms.
For example each atom of the element carbon has 6
protons (+).
To be balanced, how many electrons (-) should
carbon have?
The atomic mass of carbon is 12.
How many neutrons should carbon have?
If an element is made of atoms that have different
numbers of neutrons, then they are called isotopes.
Give it a try…fill in the table! Element Atomic # Atomic
Mass **
# Protons # Neutrons #Electrons
Carbon
Hydrogen
Oxygen
Phosphorus
Nitrogen
** Round the number for the atomic mass given in the periodic table to the
nearest WHOLE NUMBER.
There are no ions nor isotopes in this activity.
A quick word on bonding Covalent bond: a bond where two atoms share
valence electrons
Commonly seen in bonding between atoms in
biomolecules
Ionic bond: a bond where one atom completely
transfers its valence electrons to another atom
Hydrogen bond: a bond where a molecule has
slightly charged poles (making it a polar compound)
and can form slight electrostatic bonds with other
polar molecules
The Chemistry of Life! The parts of a cell are made up of large molecules
called biomolecules.
The basic units of most biomolecules contain atoms
of CARBON.
Carbon has 4 valence electrons so they can bond
covalently.
Carbon atoms in these chains and rings can connect
with other atoms of other elements to form the basic
unit of most biomolecules.
Carbohydrates Carbohydrates are molecules made of sugar.
A sugar contains Carbon (C), Hydrogen (H), and Oxygen (O) in a ratio of 1:2:1.
Examples of sugars (NOTE: all names end in –ose):
Glucose
Sucrose
Fructose
Two sugars can be linked together to form a disaccharide.
Cells use carbohydrates for sources of energy, structural material, and cellular identification.
Monosaccharide (simple sugar)
Disaccharide (this is table sugar)
Carbohydrates as an Energy
Supply Plants store the sun’s energy for future use by
making glucose and converting it to starch.
Animals break down glucose from food to produce
energy. Stored as glycogen.
Lipids Lipids are another class of biomolecules which
include fats, phospholipids.
Lipids also provide energy!
Glycerol backbone with fatty acid tails
Made of C, H, O, and P in phospholipids.
Proteins Proteins are made up of amino acids.
Proteins are twisted and folded into shapes that
determine what the protein does.
Elements Present: C,H,O,N
Proteins are extremely important!
DNA codes for proteins
Nucleic Acids A nucleic acid is a long chain of nucleotide units
Elements present: C,H,O,N, P
When we link NUCLEOTIDES together we form
nucleic acids.
DNA is made of Nucleic Acids
Biomolecule Review Name Monomer Elements
Present
Function Examples
Carbohydrate Monosaccharide C, H, O Quick energy
source
Glucose
Sucrose
Starch
Glycogen
Chitin
Lipid Glycerol
backbone, fatty
acid tails
C, H, O, P Stored energy Phospholipid
Fats
Oils
Proteins Amino Acid C, H, O, N Structure,
enzymes,
hormones
Keratin
Insulin
Lactase
Nucleic Acids Nucleotide C, H, O, N, P Genetic
information
DNA
mRNA
tRNA
Water and Solutions Water has many unique
properties
Most of the unique properties of
water result because water
molecules form hydrogen bonds
with each other.
Hydrogen Bond: A partial charge
within the water molecule causing
attraction to other water
molecules.
Ice Floats When water freezes, hydrogen bonds lock water
molecules into a crystal structure that has empty
space.
This structure makes water less dense as a solid
than as a liquid.
Water Absorbs and Retains
Heat Hydrogen bonds are constantly breaking and
reforming between molecules.
Because of this water can absorb a large amount of
heat without changing temperature.
This property of water can also help organisms
maintain a constant internal temperature.
What vocabulary word does this remind you of?
Water Molecules Stick to Each
Other Hydrogen bonds hold water molecules together.
Cohesion - the attraction of particles of the same
substance.
This is why water can move up a plant.
Water will stick to each other, so as one water
molecule is pulled up, the other water molecules it is
“stuck” to will also be pulled up. Those water
molecules will pull up the water they are “stuck” to,
and so on.
Water molecules stick to other
polar substances Adhesion - attraction between particles of different
substances.
This also helps explain why water moves up a plant.
As water moves up the tubes of the plant (called
xylem), the water will “stick” to the walls, helping it not
fall back down due to gravity.
Biological Reactions Living things carry out many chemical reactions that
help maintain a stable internal environment.
More energy is required to DRIVE these reaction
than the body can provide. The body is just too cold.
These reactions would not occur without ENZYMES!
Enzymes Enzymes ARE PROTEINS!
An enzyme is a molecule that increases that rate of
a biochemical reaction.
By assisting in necessary biochemical reactions,
enzymes help organisms maintain homeostasis.
Without enzymes you would DIE!
Enzymes Continued Enzymes FIT with reactants (called substrates) like a
lock fits a key.
This is why shape is so important.
Enzymes Continued Each enzyme has an active site where the substrate
binds.
The shape of the site determines which substrates
will bind to it.
Each enzyme acts only on specific substrates.
This is why SHAPE is so important.
When substrates bind to the enzyme, it changes
their structure and allows reactions to take place
using less energy.
Products
Products Substrate
Enzyme
Enzyme-Substrate Complex
Enzyme Enzyme
Active Site
Enzymes and Substrates
Competitive Inhibitors
Competitive Inhibitor (orange)
Inhibitors with Allosteric Site
Acids and Bases Acids: compounds that form extra hydronium ions (H+)
when dissolved in water. Your stomach uses a solution of hydrochloric acid, HCl, to
digest food.
Bases: compounds that form extra hydroxide ions (OH-) when dissolved in water. Example: Sodium Hydroxide (NaOH)
pH and buffers
pH is a measure of how acidic or basic a solution is.
pH of pure water is 7
Below 7 is acidic
Above 7 is basic
The pH of human blood must remain stable.
Which vocabulary term does this remind you of?
Buffers are substances that reacts to prevent pH changes in a solution.
Cosmetics often contain glycerol (C3H8O3) which
has three identical functional groups. Which type of
bond holds these functional groups together?
Ionic
Covalent
Hydrogen
Sulfuric
Which of the following is used by the
body as its main quick energy
source? Lipid
Carbohydrate
Protein
Nucleic Acid
Which ratio typically describes the
Carbon:Hydrogen:Oxygen in a
carbohydrate? 1:2:1
2:6:2
4:3:1
2:1:2
Elements present in lipids
include: C,H,O
C,H,O,N
C,H,O,P
C,H,O,N,P
Building blocks of carbohydrates
are: Polysaccharides
Disaccharides
Monosaccharides
Trisaccharides
Phospholipids are found in: Cell membranes
Cell Wall
Nucleus
Ribosomes
Has names ending in the suffix
-ose protein
carbohydrates
Nucleic acids
lipids
Which line indicates a reaction
where an enzyme is NOT present? A. Line A
B. Line B
Which point on the line indicates
the activation Energy? A. A
B. B
C. C
D. D
Substrate attachment occurs at
the site shape
protein
happy
active
Enzymes are which type of
biomolecule? Carbohydrate
Protein
Lipid
Nucleic Acid
True or False: Enzymes increase
the activation energy of a reaction. True
False
True or False: Enzymes are important
because they allow reaction to proceed
at lower energies.
True
False
Enzymes are specific. enzyme
substrate
protein
carbohydrate
What is the maximum number of
covalent bonds that Carbon can make
with hydrogen?
1
2
3
4