Download Chapter 3 - Biochemistry

Chapter 3 - Biochemistry
I. Carbon Compounds
A. Organic compounds
1. contain carbon covalently bonded to other carbons and other
elements
B. Carbon (backbone of organic comp.)
1. 4 bond sites
2. forms single, double, triple bonds
3. forms chains and rings
C. Functional groups (determine characteristics of a compound)
* OH (hydroxyl or alcohol group)
* NH2 (amino group)
* COOH (carboxyl group)
D. Large Carbon molecules
1. monomers - building blocks of organic compounds
2. polymer - a large molecule (monomers are linked and
repeated)
a. macromolecule - very large molecules (polymers joined)
3. condensation or dehydration synthesis - joining of 2
monomers by removing water (to form larger molecules)
Monomer +Monomer
Polymer + H2O (removing water)
4. hydrolysis - breaking apart a large molecule by adding water
Polymer + H2O (adding water)
Monomer +Monomer
II. Molecules of Life
A. Carbohydrates
1. composed of C, H, O
H to O ratio of 2 : 1
2. Functional group – OH
3. monosaccharides (monomers of carbohydrates)
a. single sugar molecule
b. glucose, fructose, galactose are most common
1) C6H12O6 molecular formula
2) isomers - same formula but different structure
c. structural formula - shows arrangement and bonding of
atoms
d. main energy source – glucose
e. Benedicts Test= Positive (orange)
f. Iodine Test= Negative (yellow)
4. disaccharides
a. double sugar (2 monosaccharides joined remove H2O)
b. sucrose, lactose, maltose
c. Benedicts Test= Negative (Blue)
d. Iodine Test = Negative (yellow)
5. polysaccharides
a. composed of many monosaccharides
b. starch - plant food storage (excess glucose)
* glycogen - animals store excess glucose in liver and
muscles
* cellulose - tough, fibrous for plant cell walls (rigid)
c. Benedicts Test= Negative (Blue)
d. Iodine Test= Positive (purple, Blue, Black)
B. Proteins
1. composed of C,H,O,N
2. Amino functional group, (NH2), and carboxyl functional
group (COOH)
3. amino acids (monomers)
Example-Tryptophan
a. 20 different kinds
1) all have central carbon bonded to hydrogen
2) R group (radical) - part that differs in each
4. dehyd. syn. joins 2 amino acids to form dipeptide
a. OH from acid(COOH) and H from NH2 forms H2O
b. C-N bond formed (peptide bond)
c. many amino acids form polypeptide
d. polypeptides form protein
5. proteins differ by number, kind, sequence of amino acids
6. each organism builds own kind of protein
C. Enzymes (type of protein)
1. act as catalysts (speed up chem. reactions)
2. characteristics
a. lower activation energy needed
b. allow reactions at body temp.
c. heat destroys (denaturing- usually occurs with heat or
pH; alters shape of enzyme)
d. work at certain temp. and pH
e. not used up in reaction
f. unchanged in reaction
g. specific in what they attack
3. Lock and Key hypothesis
a. substrate - substance enzyme attacks (key)
b. active site - place on enzyme with specific shape (lock)
c. enzyme-substrate complex - active site bound to
substrate
1) slight change in shape of enzyme
2) weakens substrate’s chem. bonds (reduces act.
energy)
4. Induced Fit hypothesis
a. substrate fit into an enzyme and enzyme forms around
the substrate
5. Coenzymes (made of vitamins) - help enzymes
Attaches to the substrate to help fit into the active site
6. Inhibitors - regulate enz. activity - can block active site
7. Types of Inhibitors
a. reversible
1) competitive inhibition
- competes with substrate for active site
- inhibitor chem. similar to substrate
- temporary attachment (doesn’t alter active site)
2) noncompetitive inhibition
- inhibitor binds with enz. at site other than active
site
- alters shape of active site
- metabolic regulators to regulate enz. activity
b. irreversible
- permanently inactivate enz.
- insecticides, poisons, Hg, Pb
- penecillin inhibits enz. transpeptidase in bacteria
cells
8.) What do we use enzymes for? (end in –ase) like Lactase
* Digestion
* Sending nerve impulses
* Muscle contractions
* Cell Energy
D. Lipids (nonpolar, insoluble in water)
1. fats, oils, waxes
2. composed of C,H,O H to O ratio much greater than 2 : 1
3. many C-H bonds store much energy
4. Functional groups: glycerol- hydroxyl
fatty acids- carboxyl
5. fatty acids and glycerol are monomers (remove H2O=Fat)
a. carboxyl end of fatty acid is polar (hydrophilic - water
loving)
b. hydrocarbon end is nonpolar (hydrophobic - water
fearing)
c. saturated f. acid (animal origin) (solid at room temp.)
1) single bonds between carbons - at least 2 H per
carbon
2) butter, lard, animal fat, palm and coconut oil
d. unsaturated f. acid (plant origin) (liquid at room temp.oils)
1) monounsaturated (one double bond)-b/t C:C
2) polyunsaturated (two or more double bonds)
3) soybean, canola, safflower, corn, olive, peanut,
sunflower
6. complex lipids
a. triglycerides - 3 fatty acids, 1 glycerol
b. phospholipids - 2 fatty acids, 1 glycerol (in cell
membranes)
c. wax - long fatty acid chain and long alcohol chain
(protective coating on plants, protective earwax)
7. Steroids
a. 4 fused carbon rings
b. testosterone, cholesterol (nerve cells
& others to function)
8. How the body uses fats?
a. energy storage
b. protect organs
c. insulation
d. store vitamins (A,D,E, K)
e. myelin sheath (nerves)
E. Nucleic Acids
1. DNA (contain hereditary instructions) and RNA (for protein
synthesis)
POLYMERS
2. polymer made of nucleotides (monomers)
Monomers= Sugar + Phosphate + Nitrogen base: A,T,C or G (DNA)
Nucleotide
A,U,C or G (RNA)