Organic Compounds

1
Organic Compounds

• Compounds that contain CARBON are called organic
• Macromolecules are large organic molecules.

2
Carbon (C)

• Carbon has 4 electrons in outer shell.
• Carbon can form covalent bonds with as many as 4
  other atoms (elements).
• Usually with
• C, H, O or N.

3
Macromolecules

• Large organic molecules.
• Also called POLYMERS.
• Made up of smaller
• building blocks
• MONOMERS.

4
Four Major Types of Biological Macromolecules
Type of Polymer Monomers making up Polymer Example
I. Carbohydrates (Polysaccharides) Monosaccharides Sugars, Starch, Cellulose
II. Lipids (not true polymers) Fats, steroids, cholesterol
III. Proteins Amino acids Enzymes, structural components
IV. Nucleic Acids Nucleotides DNA, RNA
5
I. Carbohydrates

• Made from monomers called monosaccharides (simple
  sugars)
• Short term energy
• Glucose most common, used directly in cellular
  respiration to make ATP (energy)

6
Figure 5.3 The structure and classification of
some monosaccharides
7
Disaccharides
8
PolysaccharidesComplex Carbohydrates

• 3 major types made from monomers of glucose
• Starch energy storage in plants
• Glycogen energy storage in animals
• Cellulose structural molecules in plants

9
Figure 5.6 Storage polysaccharides
10
Figure 5.7a Starch and cellulose structures 
11
Figure 5.7b,c Starch and cellulose structures 
12
Figure 5.8 The arrangement of cellulose in plant
cell walls
13
II. Lipids

• Not true polymers
• Composed of mostly glycerol and fatty acids
• Includes
• Fats energy storage
• Phospholipids membranes
• Steroids hormones, cholesterol

14
Fats are made of one glycerol and three fatty
acids
15
Double bonds between carbons cause kinks in
hydrocarbons.
H2C
CH2
H2C
CH2
H2C
CH
Kink
CH
H2C
CH2
H2C
Unsaturated fatty acid
Saturated fatty acid
CH2
Double bonds, fewer H atoms
H2C
No Double bonds, maximum H atoms
16
Figure 5.11 Examples of saturated and
unsaturated fats and fatty acids 
17
Phospholipids are made of one phosphate group and
2 fatty acids
Phospholipids are amphipathic
18
Figure 5.13 Two structures formed by
self-assembly of phospholipids in aqueous
environments   
19
Figure 5.14 Cholesterol, a steroid    
Steroids consist of a complex carbon ring
structure
20
Figure 4.8 A comparison of functional groups of
female (estradiol) and male (testosterone) sex
hormones
21
III. Proteins

• Made from monomers called amino acids
• Very different structures, very different
  functions

22
The R groups of an amino acid may be hydrophobic
or hydrophilic
23
Amino acids are joined together by a dehydration
reaction
24
Many amino acids joined together Polypeptide
chain
N-terminus
C-terminus
H
H
H
H
H
H
O
O
O
H
H
O
H
H
O
H
H
O
H
H
O
H
H
O
H
N
C
C
N
N
C
C
C
C
N
C
C
N
C
C
C
C
N
C
N
C
C
OH
N
C
CH2
CH2
H
CH2
CH2
CH
CH2
CH3
CH3
H3C
OH
C
OH
SH
O
OH
25
The sequence of amino acids in the polypeptide
chain the primary structure of a protein
26
Hydrogen bonds between amino acids leads to the
secondary structure of a protein
Two common secondary structures are the ?-helix
and ?-pleated sheet
27
Further folding of the polypeptide chain
contributes to the tertiary structure of a protein
28
The joining of more than one polypeptide chain
leads to the quaternary structure of proteins
29
Heat (energy) can break up the structure of a
protein
30
Table 5.1 An Overview of Protein Functions
31
IV. Nucleic Acids

• Nucleic acids (DNA and RNA) are made of monomers
  called nucleotides

Nitrogenous base
Nitrogenous base
Phosphate group
Phosphate group
Sugar
Sugar
32
Figure 5.29 The components of nucleic acids
33
Figure 3.17b
5
3
3
5
5
3
T
T
A
A
DNA is a double helix.
C
G
C
G
C
G
G
C
A
T
A
T
T
T
A
A
C
C
G
G
G
C
G
A
T
A
T
A
T
T
A
C
G
C
G
T
A
A
T
G
C
T
A
A
T
G
G
C
C
A
T
T
A
3
5
3
3
5
5
Cartoon of base pairing
Cartoon of double helix
Space-filling model of double helix
34
Nucleic acids store the information to make
proteins
35
Figure 5.30 The DNA double helix and its
replication