Proteins Flashcards
1
Q
what are proteins?
A
polymers made up of amino acids
2
Q
amino acid structure
A
amino group, variable group and a carboxyl group
3
Q
why are amino acids soluble in water?
A
because of NH2 and the carboxyl group
NH2 - positively charged
the carboxyl group - negatively charged
4
Q
how are polypeptides formed?
A
via a condensation reaction between amino acids and it forms peptide bonds between the chains
5
Q
what are the structural levels of a protein?
A
- primary
- secondary - alpha helix/beta pleated sheets
- tertiary structure
- Quaternary structure = different polypeptide chains/ prosthetic groups
6
Q
what are the two types of proteins?
A
globular and fibrous
7
Q
describe fibrous proteins
A
formed from parallel polypeptide chains bonded together by cross links
e.g keratin and collagen
8
Q
describe globular proteins
A
spherical shape caused by tightly folded polypeptide chains
e.g transport proteins - haemoglobin
9
Q
what are functions of proteins?
A
- transport proteins
- structural proteins
- catalytic - enzymes
- signalling - receptors/hormones
- immunological - antibodies
