Willmott 3 3D structure of proteins Flashcards
1
Q
Primary Structure
Desc
Bonds
A
Sequence of amino acids in proteins
covalent (peptide)
2
Q
Secondary Structure
Desc
bonds
A
Structural motifs: Alpha helix & Beta-sheet
H-bonds
3
Q
Tertiary Structure
Desc
Bonds
A
Folding up of polypeptide chains
Covalent Ionic H-bonds Van der Waals Hydrophobic
4
Q
Diamers
e.g.
A
2 subunits
tubulin
5
Q
Trimers
e.g.
A
3 subunits
collagen
6
Q
Tetramers
e.g.
A
4 subunits
Haemoglobin
DNA gyrase
7
Q
Protien denaturation caused by:
A
- Extreme pH
- heat
- chaotrophic agents
8
Q
Chaotrophic agents
x3
A
Urea
Guanidine hydrochloride
Mercaptoethanol
9
Q
renaturation:
A
some spontaneously refold, others require chaperone proteins for assistance
10
Q
Ribonuclease
A
catalyses hydrolysis of RNA
-small protein = 124 amino a.s
8x cysteine residues, forms 4 disulphide bonds
fully denatured & renatured in vitro
11
Q
pH of proteins
Pepsin
Trypsin
Alkaline Phosphatase
A
low pH
Norm pH7
High pH
