proteins Flashcards
•To learn the chemical nature of proteins and of their building blocks, the amino acids. •To understand the four different levels of protein structure, and the forces that regulate them. •To understand the close link between the structure and function of proteins.
1
Q
what types of proteins are there?
A
- enzymes, structural, signalling, regulatory, transport, sensory, motor, defence, hormonal, storage etc
2
Q
what is a protein ?
A
- polypeptide
3
Q
what is a histone?
A
- a protein which helps DNA pack down into chromosomes
- the DNA wraps around a histone and aids in gene expression
4
Q
what is an amino acid?
A
- monomer for protein/polypeptide chain
5
Q
what is a polypeptide?
A
- a polymer chain formed from many amino acids
6
Q
what is an oligopeptide?
A
- a polypeptide formed from a small number of amino acids
7
Q
what is a peptide bond?
A
- a chemical bond between the amino acids
8
Q
what is NH2
A
- amine group
9
Q
what does an amino acid look like in general?
A
NH2-HCR-COOH
10
Q
how does a peptide/protein form?
A
- 2 amino acids join via a condensation reaction and gives off water
- a peptide bond forms between carbon (-) and nitrogen (+)
11
Q
how many levels of protein structure are there and what are the names?
A
- 4 levels
- primary, secondary, tertiary and quaternary
12
Q
what is a primary protein?
A
- amino acids are joined forming polypeptide chains, stabilised by peptide bonds (is just a simple chain)
13
Q
what is a secondary protein?
A
- polypeptide chain may form alpha helices or beta pleated sheets, stabilised by hydrogen bonds.
14
Q
what is a tertiary protein?
A
- polypeptide folds forming a specific shape and is stabilised by hydrogen bonds, disulfide bridges and hydrophobic interactions
15
Q
what is a quaternary protein?
A
- two or more polypeptides assemble to form a large protein molecule
- stabilised by hydrogen bonds, disulfide bridges, hydrophobic interactions and ionic interactions .
