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Flashcards in Proteins Deck (21):
1

what are the different classes of amino acids? (6)

-aliphatic
- aromatic
- sulphur containing
- basic (NH2 group)
- acidic (COOH)
- uncharged polar

2

give an example of an aliphatic amino acid?

glycine, alanine, valine

3

give an example of an aromatic amino acid?

phenylalanine

4

give an example of sulphur containing amino acids?

cysteine

5

give an example of a basic amino acid?

lysine

6

give an example of an acidic amino acid?

aspartate

7

give an example of an uncharged polar amino acid?

serine

8

what is the primary structure of a protein?

the sequence of amino acids in a polypeptide chain

9

what is the secondary structure?

the spatial arrangement of amino acid residues that are near each other in the linear sequence

10

give two types of secondary structure and the position of bonds?

ALPHA HELIX
- H bonds between every 4th N-H and C=O
BETA PLEATED SHEET
- H bonds between amide groups of linear chains

11

what is the tertiary structure?

the spatial arangement of amino acid residues that are far apart in a linear sequence

12

what bonds are present in tertiary structure? (5)

- ionic
- van der Waals
- hydrogen
- disulphide
- hydrophobic interactions

13

what are hydrophobic interactions?

intra-polypeptide interactions which occur in an environment within proteins, in which water is excluded

14

what are disulphide bridges?

strong covalent bonds between two cysteine residues

15

what is the quarternary structure?

the spatial arrangement of induvidual polypeptide chains in a multi-subunit protein

16

what causes protein denaturation? (6)

- acids
- heat
- solvents
- cross linking reagents
- chaotropic agents
- disulphidebond reducers

17

what do peptidases do?

cleavage of peptide bonds

18

what do endopeptidases do?

cleave internal peptide bonds

19

what do exopeptidases do?

cleave off one amino acid at a time

20

what do carboxypeptidases do?

cleave at -COOH terminal

21

what do aminopeptidases do?

cleave at -NH2 terminal