Proteins and Enzymes

Question 1

Bonds to stabilise a chains

Answer 1

Hydrogen

Question 2

Primary structure

Answer 2

Sequence of amino acids- held by peptide bonds

Question 3

Secondary structure

Answer 3

a helix or b sheet

Question 4

Tertiary structure

Answer 4

internal hydrophobic, external hydrophilic

Question 5

Quarternary

Answer 5

many polypeptide chains

Question 6

What forms in the brain of a person with Alzheimers?

Answer 6

insoluble amyloid fibrils

Question 7

Creutzfeldt Jacob disease

Answer 7

infectious prion protein -> insoluble aggregate

Question 8

Myoglobin

Answer 8

a helices, O2 store

Question 9

Haemoglobin

Answer 9

2 a and 2 b chains, O2 transporter, lower affinity to O2

Question 10

Haem

Answer 10

tightly bound; with protein will keep Fe in ionic form and inhibit CO binding

Question 11

T state

Answer 11

low affinity for O2- more salt bridges

Question 12

R state

Answer 12

high affinity for O2

Question 13

Bohr effect

Answer 13

increase in H+ decreases Hb O2 affinity -> more salt bridges -> T state

Question 14

Higher BPG at altidude…

Answer 14

low affinity for O2 -> more O2 release

Question 15

Collagen

Answer 15

Gly, Pro and Hyp alpha helix (gly in centre) Form staggered microfibrils (type I, II and III) with cross links

Question 16

Collagenases..

Answer 16

break down collagen

Question 17

Ehlers-Danlos

Answer 17

stretchy skin and loose joints

Question 18

Osteogenesis imperfecta

Answer 18

type 1 mutation = brittle bones

Question 19

Scurvy

Answer 19

vit C deficiency = defective collagen

Question 20

How do enzymes lower activation energy?

Answer 20

Provide groups and better orientation

Question 21

Active site

Answer 21

specific, 3D, multiple weak interactions

Question 22

Vmax

Answer 22

Theoretical max rate of reaction

Question 23

Km

Answer 23

Michaelis constant- affinity

= k2 + k3 / k1

Question 24

Factor affecting rate of reaction

Answer 24

substrate concentration
enzyme concentration
temperature
pH
inhibitors

Question 25

Irreversible covalent modification

Answer 25

eg. serine nerve agonists

Question 26

Reversible competition

Answer 26

increases Km

Question 27

Irreversible competition

Answer 27

Lowers Vmax

Question 28

Cofactors..

Answer 28

metal ions (active sites) and coenzymes (carry reaction components)