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Flashcards in Proteins Deck (25):
1

What 2 functional groups does an amino acid have?

an amino group (NH2)
a carboxylic acid group (COOH)

2

What forms do proteins consist of only?

L forms (left)

3

Give an example of an amino acid with an acidc R group.

Aspartic acid

4

Give an example of a basic amino acid.

arginine

5

Give an example of an uncharged polar amino acid.

glutamine

6

Give an example of a polar amino acid.

glycine, alanine

7

How is a peptide bond formed?

condensation reaction

8

What is meant by the 'primary structure' of a protein?

the sequence of amino acids

9

How many different types of amino acid are there?

20

10

What is meant by the 'secondary structure' of an amino acid?

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

11

What are the 2 forms the secondary structure can take?

alpha helix
beta pleated sheets

12

How is the shape of the alpha helix maintained?

by hydrogen bonds between C=O group and N-H group

13

What is meant by the 'tertiary structure' of a protein?

the spatial arrangement of amino acid residues that are FAR APART in a linear sequence

14

What are the 5 ways that the tertiary structure is maintained? (Bonding)

-van der waals
-hydrogen bonding
-ionic interactions
-disulphide bridges (between cysteine residues)
-hydrophobic interactions

15

What is meant by the 'quaternary structure' of a protein?

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

16

What is an example of a complex with a quaternary structure?

haemoglobin

17

What structures of protein are affected by denaturation?

secondary and tertiary

18

Why is primary structure of protein not affected by denaturation?

the reactions aren't strong enough to break the peptide bonds

19

Give 2 examples of causes of denaturation of proteins.

acids
heat

20

What are some examples of the effects of denaturation? (4)

-decreased solubility
-altered water binding capacity
-loss of biological activity
-improved digestibility

21

What do peptidases do?

cleave peptide bonds

22

What do endopeptidases do?

cleave internal bonds of protein

23

What do exopeptidase do?

cleave away one amino acid at a time

24

What do carboxypeptidases do?

cleave at COOH terminal

25

What do amino peptidases do?

cleave at NH2 terminal