Download Biochemistry Notes

Organic Chemistry
The Chemistry of Carbon
A. Carbons Versatility
1. Tetravalent - can form four bonds with other
elements
2. May form double bonds and triple bonds.
3. Bond with itself forming Chains of various
lengths
4. The chains may branch.
5. May form rings
B. Characteristics of Organic
Compound
1. Carbon backbones
2. Composed of single units called monomers
3. Monomers are joined in a condensation
reaction that usually occurs between the –OH
groups of two monomers. H2O is removed
linking the two monomers with an oxygen
bridge
4. Polymers- many joined monomers
5. Polymers are broken down in Hydrolysis
II. 4 Major Classes of Organic
Compounds
A. Carbohydrates
1. Functions of Carbohydrates
a) Quick energy- sugar,
glycogen and starch
b) Structure- cellulose,
chitin
2. Structure of Carbohydrate
a) Glucose(C6H12O6) and Fructose (C6H12O6)
are single sugars called monosaccharides
b) Isomers- compounds with the same molecular
formula but different structures
C) Disaccharide- two monosaccharides joined in a
condensation reaction. An example is sucrose.
D) Polysaccharides- long chains of sugars
1) Starch- storage form of carbohydrates in plants (1-4ά)
2) Glycogen- storage form of carbohydrate in animals (1-4ά)
3) Cellulose- structural polysaccharide in plants (1-4β)
B. Lipids
Animal Fat
Plant Oils
Waxes
1. Functions
a) Long term energy storage
b) Structure- form membranes
c) Insulation
2. Structure- 1 glycerol with
fatty acid chains
3. Types of Lipids
a) Saturated fat- each carbon is bonded with
two hydrogens in the fatty acid chain
1) Animal fats
2) Solid at room temperature
3) Bad for you. (Cause arteriosclerosis)
b) Unsaturated Fat- contains double
bond between some of the carbons
1. Plant oils
2. Liquid at room temperature
3. Better for you. More easily absorbed
c. Phospholipid- forms the
membrane around cells
C. Proteins
1 Functions:
a)
b)
c)
d)
e)
f)
Structure Example: collegen
Transport Example: hemoglobin
Fight Disease Example: antibodies
Communication Ex: Hormones
Movement Ex: actin and myosin
Control Chemical Reactions
Example: enzymes
2. Structure- Shaped to perform function
a) Proteins are made of monomers called amino
acids
b) Amino acid structure:
R group
Amino
group
Acid
group
c) All amino acids have the same amino and acid
groups but different r groups
d) Peptide bonds join amino acids in condensation
reactions forming a dipeptide
Amino Acids with Hydrophobic Side
Groups
Note the methyl groups at the bottom of the chains
Amino Acids with Hydrophilic Side
Groups
Note the charged or polar groups at the bottom of the chains
And Some Amino Acids are in
Between
Hydrophobic and Hydrophilic regions influence protein shape.
3. Levels of Protein Structure
a) 1st Level: Linear sequence of
amino acids
b) 2nd Level: Spiraling and pleating
c) 3rd Level: Bending and folding
d) 4th Level: Intertwining of multiple
polypeptides
4. Proteins are able to function because of their complex
shape
5. Enzymes Function (Enzymes control chemical
reactions)
E
Enzyme
+
S
Substrate

E/S
Enzymesubstrate
complex

E +
Enzyme
P
Product
a) Enzymes are specific to a substrate (like a lock and key)
b) Enzymes are named by adding “ase” to the name of the
substrate
The Catalytic Cycle of Enzymes
Enzyme with empty
active sites Hydrolysis
Substrate
occurs
(Sucrose)
Substrate is converted to
Substrate binds with the enzyme
forming an enzyme-substrateproduct
complexand the enzyme is not
used up. The enzyme’s active
sites are free to accept another
substrate molecule
The Catalytic Cycle of Enzymes
a) The enzyme binds with the substrate at the
active site. Induced fit stresses key bonds
b) The substrate is converted to product
Factors Affecting Enzyme
Activity
1. Substrate Concentration
Adding more substrate will
have no affect on the rate of
the reaction passed the
SATURATION POINT
R
A
T
E
Low
CONCENTRATION
High
2. Temperature
Human enzymes
have an optimal
temperature of
37º Celsius.
Higher
temperatures
cause the
enzymes to
denature.
37oC
R
A
T
E
0
10
20
30
40
50
50
70oC
3. pH
R
A
T
E
Most enzymes have
an optimal pH of 7.
Some enzymes
function more
effectively in acidic or
basic conditions.
1 2 3 4 5 6 7 8 9 10 11 12 13 14
Nucleic Acids
D. Nucleic Acids- large complex molecules
formed of smaller smaller units called nucleotides
1. Nucleic acid structure
A) Nucleotide consists of a sugar, a phosphate
group and a nitrogen base
B) Sugars:
1) Ribose in RNA
2) Deoxyribose in DNA
C) Bases:
1) Purines (2 rings) Adenine & Guanine
2) Pyrimidines (1 ring) cytosine & Thymine
Nucleic Acids
2. DNA structure is a double helix with the
base pairing of Thymine with Adenine
and Cytosine with Guanine.
3. RNA structure is a single spiral with
Uracil replacing Thymine. RNA Carries
the genetic code from the nucleus to the
ribosome.
4. Nucleic Acid Functions
a) DNA and RNA carry the genetic code. I.e. The
information for constructing proteins
b) Other related nucleotides like Adenosine
Triphosphate (ATP) supplies energy to the cell
c) Many other nucleotides and dinucleotides are
involved in electron transport.
– GTP, UTP, CTP
– dGTP, dATP, dCTP, dTTP
– AMP, NAD+, NADP, FAD