Animation
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Biochemistry
Biochemistry = the chemistry of life
Elements - These are single substances which cannot be
broken down any more. there are 110 different
elements that are known to man.
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Biochemistry
The four most common elements in living things are:
1) Carbon
2) Hydrogen
3) Oxygen
4) Nitrogen
Black = Carbon; Yellow = Hydrogen; Red = Oxygen
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Biochemistry
Each element contains atoms. Each atom has a structure
which is called the atomic structure. The atomic structure
includes:
1) Protons - Positively
charged particles
2) Neutrons - Neutral
(uncharged) particles
3) Electrons - Negatively
charged particles
Electrons
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Biochemistry
Each element has a specific number of electrons
which are distinctly arranged in the shell
First shell - 2 electrons
Second shell - 8 electrons
A stable atom will have
8 electrons in the outer
shell (or, if there's only
one shell, a stable atom
would have 2 electrons)
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Biochemistry
Is this a stable atom? Why or why not?
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Biochemistry
Compounds - These are two or more elements combined.
These elements are bonded together. There are two types
of bonds which may be used to link elements together.
Molecular model
of water. It is
a compound because
there are three
elements bonded
together.
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Biochemistry
Ionic Bonding - The atoms transfer the electrons. The
atoms acquire a charge and then become ions.
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Biochemistry
Covalent Bonding - The elements share atoms to
form a molecule.
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Biochemistry
Formula - A formula shows the ratio of elements, or the
structure of the compounds. There are two types of
formulas:
1) Empirical Formula - This shows the symbols of the
elements, followed by a numerical subscript which
identifies the ratio of the atoms.
Ex: H2O means there are two hydrogen
atoms and one oxygen atom (if nothing is
written after the letter, it is understood that
there is only one there).
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Biochemistry
H2O2 = two hydrogen and two oxygen
How many of each is in a molecule of
sugar?
C6H12O6
6 Carbon
12 Hydrogen
6 Oxygen
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Biochemistry
Structural Formula - This formula shows how the atoms
are arranged (its structure!!). For example, sugar
C6H12O6 looks like this.
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Biochemistry
Glucose and fructose have the same molecular formula
C6 H12O6, but they have different structural formulas
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Biochemistry
Inorganic Compounds - These do not contain both
carbon and hydrogen. They may contain one or the other,
but they don't contain both. Examples of inorganic
compounds:
Water - H2O
Acids - HCl
Salts - NaCl
Bases - NaOH
CO2
*** Water is essential for life functions of cells.
It is a solvent for other substances to dissolve in.
Most chemical reactions occur only in water solutions
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Biochemistry
Organic compounds - These are formed in nature by
activities of living organisms. ***They always contain
both carbon and hydrogen.
Carbon is special because
it can form 4 covalent
bonds while most others
can only form 2 bonds.
Therefore, it can form
long chains and rings.
Count the number of bonds to carbon
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Biochemistry
There are 4 major kinds of organic compounds found in
living things:
1) Carbohydrates
2) Proteins
3) Lipids (Fats)
4) Nucleic Acids
Carbohydrates - These
are compounds that are
made up of C, H & O.
Ex: C6H12O6
12:6 = 2:1
The elements are usually
in a ratio of
2(H) : 1(O)
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Biochemistry
There are 3 types of carbohydrates:
A) Monosaccharides
Mono = 1
B) Disaccharides
Di = 2
C) Polysaccharides
Poly = 3 or more
A) Monosaccharides These are simple sugars. They
usually end in the letters "ose" - glucose, fructose,
galactose etc. These have the molecular formula of
C6H12O6
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Biochemistry
B) Disaccharides - These are carbohydrates made up of
2 simple sugars put together.
Ex: Maltose, Sucrose, Lactose
Sucrose
is two
glucose
molecules
put
together
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Biochemistry
If you put two glucose molecules
together (C6H12O6), how many C's
H's and O's should you have
Actually, the formula is
C12H22O11
Why?
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Biochemistry
2 hydrogen and 1 oxygen are missing - in order to put
these two molecules together, a water molecule must
be taken out. This process is called dehydration synthesis
(dehydration = lose water)
(synthesis = put together)
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Biochemistry
Animation of dehydration synthesis and hydrolysis
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+
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=
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Biochemistry
Hydrolysis - This is the opposite process of dehydration
synthesis. It is when you add water to a compound and
the compounds separate (break down) Hydro = water
Lysis = break up
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Biochemistry
Polysaccharaides: These are carbohydrates made
up of many sugar units synthesized into long chains called
polymers. The units may be the same, or they may
be different. Examples: starches, cellulose etc.
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Biochemistry
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Biochemistry
Proteins - Proteins contain C, H, O, and N. They may
also contain sulfur. They are used to make cell
structures such as the membrane as well as other things
*** All enzymes are proteins!!
*** Many hormones are proteins
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Biochemistry
The units which make up proteins are called amino
acids. You will learn this also as "the building
blocks of proteins" An amino acid has two distinct
parts: 1) an amino group 2) a carboxyl group
H
H
O
N
-C
OH
Amino Group
Carboxyl Group
COOH
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Biochemistry
Every amino acid has both of these groups (amino group
and carboxyl group). However, each amino acid is
different by what is between the two groups. The
different group in the middle vary, and are represented
by the letter "R"
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Biochemistry
A protein consists of many of these amino acid units
linked together. They are linked together (synthesized)
by the process of???????? __________________
Dehydration Synthesis
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Dehydration Synthesis of a protein
Dipeptide
(AKA: Protein)
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Biochemistry
Polypeptide (AKA: Protein)
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Biochemistry
A protein with many amino acids linked together
AKA: Polypeptide
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Biochemistry
A protein has 1 or more chains of amino acids. They may
be folded, twisted or coiled.
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Biochemistry
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Biochemistry
Lipids - These are fats and oils (ask me about a fat lip)
Lipids are made of C, H< O, but are in a different ratio
than carbohydrates.
The H:O ratio is greater than 2:1 lipids are used for:
H:O Ratio
Carbohydrate Lipid C12H24O2
2:1
>2:1
24:2
12:1
1) Stored Energy
3) Cushioning Organs
2) Cell Structures (cell membranes)
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Biochemistry
A lipid consists of 3 fatty acids and 1 glycerol
1
glycerol
3 fatty
acids
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Biochemistry
A lipid is made by the process of dehydration synthesis
of 3 fatty acids and 1 glycerol molecule.
FluidMosaic
Model
of
Cell
Membrane
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Biochemistry
Enzymes - ALL enzymes are proteins!!!
Enzymes control chemical reactions. They help the
reactions to occur, but they are not changed or used
up in the reaction!!!
Therefore, they can be used over and over again (although,
eventually, they do break down (disintegrate) over time).
***Enzymes are classified as catalysts.
Catalysts are substances that increase the rate of a
reaction, but are not changed.
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Biochemistry
Structure of Enzymes:
1) They are proteins - so they are made up of? ____
Amino acids!!
2) They may have a non-protein coat called a co-enzyme
The coenzyme helps the enzyme function properly and
without it, some enzymes may not be able to function at
all. Vitamins act as coenzymes.
3) Enzymes have an active site. This is where enzyme
action occurs. The enzymes are usually bigger than
the molecules that they act upon.
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Biochemistry
4) Enzyme-substrate complex The enzyme forms a temporary
association with the substances
whose reaction it controls.
Active
Site
The point where contact
is made is called the
active site
The substance acted
upon is called the
substrate
After the reaction is over, the
enzyme separates from the substrate
and may be used elsewhere.
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Biochemistry
Which is the enzyme and which is the substrate? How do you
know? What kind of reaction is this?
The enzyme does not get changed in
this reaction - therefore it is the green
one. Another clue is that it is bigger
than the substrate.
This is a hydrolysis reaction because the
substrate is being broken down
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Biochemistry
"Lock and Key" Model A lock has a specific shape. Only one specific key will
open that lock. This model is used to describe how
enzymes work - their shape has to fit the substrate,
otherwise, the enzyme will not work on the substrate.
Notice
how they
fit together,
like a lock
and a key
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Biochemistry
Hydrolysis with enzyme
action
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Biochemistry
Dehydration
synthesis of
product with
use of an
enzyme
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Biochemistry
Dehydration synthesis of a product with enzyme
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Biochemistry
6) Replacement of Enzymes
Enzymes are only around for a limited time because they
do decompose at some point. Therefore, organisms
must synthesize enzymes continuously. The DNA of the
cell has the "blueprint" for making enzymes.
7) Name of enzymes:
Enzymes end in the letters "ASE" (KNOW THIS!!!)
They are usually named after the substrate that it acts upon
Ex: Maltase works on maltose
Lipase works on lipids
This is not always true - salivary amylase works on
carbohydrates
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Biochemistry
Chemical Nature of Enzymes
1) Rate of enzyme action
The rate varies with conditions in the cellular environment:
There are 3 factors that affect the rate of enzyme actions
a) pH level (acidic or basic)
b) Temperature
c) How much (concentration) of enzyme OR
substrate is available.
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Biochemistry
a) pH. pH is measured on a scale of 0-14. The low
end is acidic. The high end is basic. 7 is neutral (middle)
0-1
234
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strongly
acidic
moderately
acidic
slightly
acidic
(7)
neutral
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slightly
basic
10 11 12
13 14
moderately
basic
strongly
basic
How to remember if a pH is acidic or basic: go from left to right
when you read - low numbers on left, high numbers on right
Alphabet: "A" is left of "B" - low numbers are acidic, high
numbers are basic
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Biology
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Biochemistry
Each enzyme acts most effectively within a certain pH range
Ex: Pepsin (found in your stomach) works best in acidic
conditions. Your stomach is very acidic. Would pepsin
work in your mouth?
B) Temperature
The rate of the reaction is generally slow at low temperatures.
As the temperature increases, so does the rate of the reaction,
but only up to a point!! If the temperature gets too high,
then the shape of the enzyme changes and no longer functions.
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Biochemistry
When an
enzyme's
shape is
changed due
to high
temperatures,
it is said
to be
denatured.
They can't
fit into the
substrate
any more.
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Biochemistry
**** Human enzymes become denatured at temperatures
near 400 C which is a few degrees above body temperature
Human body temperature is 370 C
C) Relative amount (aka: concentration) of enzyme
or substrate
The rate of the enzyme activity will increase as the
amount of substrate increases, but only up to a point.
The rate levels off as more substrate is added (because
you only have so much enzyme available to work on the
substrate)
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Biochemistry
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Biochemistry
Cellular Respiration
Cellular respiration is the process where chemical bond
energy in food is converted to a form of useable energy.
** Chemical energy is always called ATP (which stands for
Adenosine Triphosphate). Tri = 3
(3 phosphates)
ATP is released by the process of hydrolysis
The reaction is controlled by the enzyme "ATP-ase"
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Biochemistry
H2 O +
ATP
ATP-ase
ADP + Energy
This formula may be reversed (that is why there are
two arrows in different directions)
The arrow pointing to the right is ?
The arrow pointing to the left is?
Hydrolysis
Dehydration synthesis
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Biochemistry
There are 2 types of cellular respiration:
1) Aerobic Respiration - Free oxygen is used
2) Anaerobic Respiration - Free oxygen is not used
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Aerobic Respiration
C6H12O6
+
6O2
Enzymes
6 H2O + 6 CO2 +
36 ATP
Glucose is broken down into CO2 and H2O
Bond energy is released gradually. Why?
Energy released too quickly
would be too much
for the cell to handle.
Usually 36 molecules of ATP is released for every molecule
of glucose used. 36 ATP is very important - remember it!!
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Aerobic Respiration
This equation is balanced because all of the numbers on the
left of the arrow equal the numbers on the right of the arrow
C6H12O6 + 6 O2 --------> 6 H2O + 6 CO2
C's on left = ____? 6
H's on left = ____? 12
O's on left = ____? 18
C's on right = _____?
H's on right = _____?
O's on right = _____?
6
12
18
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Aerobic Respiration
There are 2 phases of aerobic respiration:
1) The first phase is anaerobic (no oxygen is present)
It occurs in the cytoplasm just outside of the mitochondria.
When glucose is broken down, it's called glycolysis
is broken
Glucose -----------> Pyruvic acid + 2 ATP
down into
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Aerobic Respiration
2) The second phase is aerobic (oxygen present)
•
•
•
•
•
Pyruvic acid enters the mitochondria
Pyruvic acid is oxidized (loses H atoms)
34 Molecules of ATP are produced
CO2 and H2O are produced as waste products
There is a net gain of 36 molecules of ATP (2 from
phase 1 and 34 from phase 2).
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Aerobic Respiration
Glucose + 2 ATP -------> 2 Pyruvic acid + 2 ATP (Phase 1)
(Cytoplasm)
2 Pyruvic acid + O2 ---------> CO2 + H2O + 34 ATP (Phase 2)
(Mitochondria)
Net output : 36 molecules of ATP per molecule of glucose
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Anaerobic Respiration
Anaerobic Respiration (AKA: Fermentation) is done
without free oxygen present.
Organisms that carry out anaerobic respiration:
Yeast
Bacteria
Your muscle cells
(sometimes)
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Anaerobic Respiration
The end products of anaerobic respiration vary
depending on the type of organism that is carrying
out the anaerobic respiration!!!!
Yeast:
Glucose ----------> 2 Alcohol + 2 CO2 + 2 ATP
CO2 is what makes the dough rise!!!
Bacteria & Muscle Cells
Glucose --------> 2 Lactic Acid + 2 ATP
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Aerobic Vs. Anaerobic
Aerobic
36 ATP Produced
Anaerobic
2 ATP Produced
Oxygen on left of arrow No Oxygen anywhere!
Carbon Dioxide, Water
& 36 ATP are products
Carbon Dioxide, Lactic
Acid OR Alcohol are the
products. NO WATER
is produced
Plants & Animals
Yeast, Bacteria
or Muscle Cells
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Biochemistry
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