Proteins Flashcards
1
Q
What are proteins made up of?
A
- monomers called amino acids
2
Q
Draw + label the general structure of an AA.
A
- NH2 (amine group)
- COOH (carboxyl group)
- R (variable side group - 20 options)
- H
3
Q
What type of bond forms from a condensation reaction between 2 AAs?
A
- peptide bond
4
Q
Describe how dipeptides are formed.
A
- 2 AAs are joined together by a peptide bond, formed via a condensation reaction
- peptide bond forms between OH of carboxyl group + H of amine group
5
Q
Describe how polypeptides are formed.
A
- many AAs are joined together by peptide bonds, formed via condensation reactions
6
Q
What may functional proteins contain?
A
- 1 or more polypeptide chains
7
Q
Describe the primary structure of a protein.
A
- sequence of AAs in a polypeptide chain
8
Q
Describe the secondary structure of a protein.
A
- sequence of AAs cause H bonds to form in parts of polypeptide chain making it coil into an α-helix shape or fold into β-pleated sheets
- hydrogen bonds form between C=O of carboxyl group of 1 AA, + H in amine group of another AA, to hold secondary structure
9
Q
Describe the tertiary structure of a protein.
A
- further folding of secondary structure forms a unique 3D shape, which is held in place by ionic, H + disulphide bonds
- ionic + disulphide bonds form between R-groups of diff AAs
- disulphide bonds only occur when there’s sulfur in the R groups
10
Q
Describe the quaternary structure of a protein.
A
- 3D structure made up of more than 1 polypeptide chain
11
Q
Why is the primary structure of a protein important?
A
- bc if even 1 AA in sequence is diff, ionic, H + disulphide bonds will form in diff. locations, resulting in a diff 3D shape
- means enzymes will have a diff shaped active site + carrier proteins will have a diff shaped binding site
12
Q
Describe the biochemical test for proteins.
A
- add biuret
- if proteins are present, solution will turn from blue to purple
