proteins Flashcards
1
Q
what is an amino acid?
A
a monomer which makes up proteins
2
Q
what does the shape/function of a protein depend on?
A
sequence, type and number of amino acids
3
Q
how many amino acids are there?
A
20
4
Q
what is the general structure of an amino acid?
A
- central carbon
- NH2 amine group on left
- COOH carboxylic acid group on right
- H on bottom
- R group on top
5
Q
how are proteins joined?
A
peptide bonds
6
Q
describe how a peptide bond forms
A
- hydroxyl of carboxylic acid and hydrogen of amine group are lost (1 water molecule)
- remaining carbon and double oxygen, bond to nitrogen of adjacent amino acid
- water is released
- condensation reaction
7
Q
describe the primary structure of a protein
A
- sequence of amino acids
- peptide bonds
8
Q
describe the secondary structure of a protein
A
- initial folding of polypeptide chain
- hydrogen bonding
- alpha helix or beta pleated sheets
9
Q
describe the tertiary structure of a protein
A
- overall 3D shape
- hydrogen & ionic bonds
10
Q
describe the quaternary structure of a protein
A
- 2+ polypeptide chains stacked to form a single protein molecule
- hydrogen bonding & disulfide bridges
11
Q
what is a globular protein?
A
- almost spherical
- soluble
- metabolic functions
12
Q
what is a fibrous protein?
A
- regular amino acid sequence
- insoluble
- structural functions
13
Q
describe the structure of elastin
A
- fibrous
- short sequences of 3-9 amino acids
- flexible
- recoils after being deformed
- insoluble
14
Q
describe the function of elastin
A
- allows tissues in the body to shrink out and back
e.g. bladder, lungs
15
Q
describe the structure of collagen
A
- fibrous
- triple helix
- flexible
- no stretch
- insoluble
