CH.3 Biochemistry

Question 1

Chemistry of a carbon atom

Answer 1

4 valence electrons, can form four single covalent bonds and also able to form double or triple bonds

Question 2

define hydrocarbon chain

Answer 2

a chain of carbon atoms that form bonds with multiple hydrogen atoms as well as other carbon atoms, forming a chain of carbon surrounded by hydrogen

Question 3

define functional group

Answer 3

Group of atoms linked by strong covalent bonds that tends to behave as a distinct unit in chemical reactions with other atoms.
eg. hydroxyl, carboxyl, amino, methyl and phosphate

Question 4

describe structure and function of carbohydrates

Answer 4

• contain a 1:2:1 ratio of carbon, hydrogen, oxygen
• they are polar
• used for cellular respiration(ATP), structural components(DNA,RNA,ATP), glycolipids, glycoproteins
• found in grains, legumes, fruit

Question 5

types of carbs

Answer 5

Monosaccharides
- one monomer
- glucose, fructose, galactose
Disaccharides
- two monomers formed by dehydration
- sucrose, lactose, maltose
Polysaccharides
- many monomers
- starch, glycogen, cellulose

Question 6

specify major elements of lipids

Answer 6

carbon, hydrogen, oxygen
very little amounts of oxygen, mainly C and H

Question 7

most common form of lipid

Answer 7

fatty acid
Hydrocarbon chain with little oxygen
non-polar

Question 8

define hydrophilic

Answer 8

able to mix with water

Question 9

define hydrophobic

Answer 9

unable to mix with water

Question 10

three types of lipids

Answer 10

Triglycerides
phospholipids
steroids

Question 11

Triglycerides

Answer 11

3 fatty acid chains bound to glycerol by dehydration
function: protection, insulation, energy storage

Question 12

Phospholipids

Answer 12

2 fatty acids attached to glycerol and phosphate group
polar head and non-polar tail
major component of phospholipid bilayer in cell membrane

Question 13

Steroids

Answer 13

4 interlocking hydrocarbon rings, cholesterol is base for all steroids
functions: hormones, vitamin D, bile salts

Question 14

saturated vs unsaturated fats

Answer 14

Saturated: single carbon bonds and solid at room temp.
Unsaturated: double carbon bonds, liquid at room temp.

Question 15

Polyunsaturated vs monounsaturated fats

Answer 15

Polyunsaturated: 2+ carbon double bonds
Monounsaturated: 1 carbon double bond

Question 16

why are carbs generally hydrophilic

Answer 16

they have polar OH groups

Question 17

why are lipids generally hydrophobic

Answer 17

they have many non polar bonds

Question 18

elements in protein molecules

Answer 18

C,H,O,N,S,P
C,H,O,N always present
S,P, sometimes present

Question 19

structure of amino acids

Answer 19

carbon in middle surrounded by amino acid, side chain, carboxyl group, and H atom

Question 20

how many different amino acids are there

Answer 20

20

Question 21

what are the three types of amino acids based on number of them attached together

Answer 21

dipeptide - 2 amino acids
tripeptide - 3 amino acids
Polypeptide - 10+ amino acids

Question 22

4 levels of structure of a protein molecule

Answer 22

primary- amino acids form polypeptide chain
secondary- formation of helix or sheets
tertiary- alpha helix and/or beta sheets fold to form a
compact globular molecule held together by
intramolecular bonds
quaternary- 2 tertiary structures combine, making a
functioning protein

Question 23

major functions of protein and examples

Answer 23

1. structural, collegen/keratin
2. regulatory, pancreas(insulin and glucagon)
3. contractile, actin and myosin
4. Immunological, antibodies
5. transport, hemoglobin transports oxygen
6. catalytic, sucrase

Question 24

structure of nucleic acids

Answer 24

C,H,O,N,P
Nucleotides are building blocks for nucleic acids

Question 25

nucleotide structure

Answer 25

one or more phosphate groups, a pentose sugar, and a base (Adenine, Guanine, Thymine, Cytosine)
Nucleotides are building blocks for nucleic acids

Question 26

nucleotide function

Answer 26

Nucleotides can be assembled into nucleic acids (DNA or RNA) or the energy compound adenosine triphosphate.

Replication / Transcription / Translation

Question 27

what is ATP

Answer 27

high energy source
ribose sugar, adenine base, 3 phosphates
covalent bonds
help in muscle contractions, brining molecules into cells, and anabolic reactions