3.1.4 Proteins Flashcards
1
Q
Monomers of proteins
A
Amino acid -> polypeptide -> protein
2
Q
How many amino acids are there?
A
100
3
Q
How many amino acids occur in living organisms?
A
20
4
Q
What does each amino acid differ by?
A
The R group
5
Q
Components of an amino acid
A
- R group
- Carboxyl group
- Amino group
6
Q
Amino acid: R group
A
- Side chain
- Variety of different chemical groups different for each amino acid
7
Q
Amino acid: Carboxyl (COOH) group
A
an acidic group which gives the amino acid the acid part of its name
8
Q
Amino acid: amino (NH2) group
A
basic group where the amino part of the name amino acid comes from
9
Q
Formation of proteins
A
- Condensation reaction between 2 amino acids forms a peptide bond (between the -OH of the carboxyl group and the -H of the amino group of another amino acid)
- NH2 joins to COOH
- There is a free NH2 at one end and a free COOH group at another end
10
Q
Dipeptide
A
Formed by the condensation of 2 amino acids
11
Q
Polypeptides
A
Formed by the condensation of many amino acids
12
Q
4 structure stages of proteins
A
- Primary
- Secondary
- Tertiary
- Quaternary
13
Q
Primary structure of proteins
A
- The order and number of amino acids in a protein
- Contains initial sequence of amino acids + so determines the protein’s function and 3d shape
- Specific for each protein (small alteration can affect protein function
14
Q
Secondary structure of proteins
A
- The shape of the amino acid chain
- Hydrogen bonds form between the H of the -NH (overall positive charge) and the O of the C=O (overall negative charge)
- This causes the polypeptide chain to be twisted into a 3D shape (either alpha helix or beta pleated)
15
Q
Tertiary structure of proteins
A
- Interactions between R groups
- 3D shape of the protein (makes each protein distinct and recognisable)
- Further twisting + folding
- Disulfide bridges, ionic bonds and hydrogen bonds form
