Biochemistry

Question 1

do enzymes affect the position of the equilibrium?

Answer 1

no, they speed up the rate at which a reaction reaches equilibrium

Question 2

what do enzymes do to the activation energy?

Answer 2

enzymes lower the activation energy

Question 3

enzymes with a cofactor are called

Answer 3

holoenzyme

Question 4

enzymes without a cofactor

Answer 4

apoenzyme

Question 5

protein kinases carry out which reaction

Answer 5

phosphorylation reactions

Question 6

Vmax

Answer 6

maximum rate of reaction at unlimited substrate concentration

Question 7

Km

Answer 7

50% Vmax

Question 8

competitive inhibitor

Answer 8

binds to active site, Vmax remains same, Km varies

Question 9

non-competitive inhibitor

Answer 9

binds to site other than active site, Km remains same, Vmax varies

Question 10

nucleoside

Answer 10

base and sugar

Question 11

nucleotide

Answer 11

nucleoside and phosphate group

Question 12

purines

Answer 12

adenine and guanine

Question 13

pyrimidines

Answer 13

uracil, cytosine, thymine

Question 14

eukaryotic cells have three types of polymerases

Answer 14

pol I, pol II, pol III

Question 15

pol II

Answer 15

synthesises all mRNA

Question 16

transcription stages

Answer 16

RNA polymerase binding
DNA chain separation
transcription initiation
elongation
termination

Question 17

translation stages

Answer 17

initiation, elongation, termination

Question 18

3 tRNA binding sites

Answer 18

exit, peptidyl, aminoacyl

Question 19

degenerate

Answer 19

many amino acids have more than one codon

Question 20

unambiguous

Answer 20

each codon codes only for one amino acid

Question 21

glycolysis

Answer 21

conversion of glucose to pyruvate

Question 22

what is the net gain of ATP per glucose

Answer 22

4 ATP

Question 23

which kinase phosphorylates glucose

Answer 23

hexokinase

Question 24

which kinase phosphorylates fructose-6-phosphate

Answer 24

phosphofructokinase

Question 25

what does pyruvate kinase do?

Answer 25

converts phosphoenolpyruvate to pyruvate

Question 26

phosphofructokinase

Answer 26

key enzyme in control of glycolysis

Question 27

negative modulators

Answer 27

ATP citrate H+

Question 28

positive modulators

Answer 28

AMP fructose-2 6-biphosphate

Question 29

NAD in glycolysis

Answer 29

NAD+ reduced to NADH + H+

Question 30

from each acetyl-coA, TCA cycle generates

Answer 30

3 NADH + H+ 1 FADH2 1 GTP 2 CO2

Question 31

standard redox potential

Answer 31

a measure of how readily a substance donates an electron negative= reduced form of x has lower affinity for electrons than hydrogen positive= reduced form of X has higher affinity for electrons than hydrogen

Question 32

inhibitors of oxidative phosphorylation

Answer 32

cyanide azide CO