exam 1 glycolysis

Question 1

where does glycolysis happen?

Answer 1

cytosol

Question 2

what are the products of glycolysis?

Answer 2

ATP, NADH, pyruvate

Question 3

in fast glycolysis, pyruvate is converted to?

Answer 3

lactic acid and alanine

Question 4

in slow glycolysis, pyruvate does what?

Answer 4

pyruvate -> mitochondria -> aerobic metabolism

Question 5

glycolysis yields precursors to?

Answer 5

the aerobic system- krebs and electron transport chain

Question 6

glycolysis is the only source of metabolic energy in which cells and tissues?

Answer 6

erythrocytes, renal medulla, sperm

Question 7

what is the preparatory phase of glycolysis?

Answer 7

phosphorylation of glucose- brings glucose in and traps it and then adds a phosphate to it

Question 8

bis-phosphate implies what?

Answer 8

2 separate phosphates

Question 9

diphosphate implies what?

Answer 9

2 joined phosphates

Question 10

1 glucose yields?

Answer 10

2 pyruvates

Question 11

DHAP converts into?

Answer 11

G3P

Question 12

what enzyme is needed for glucose - glucose-6-phosphate? (phosphorylation)

Answer 12

hexokinase/glucokinase, uses 1 ATP

Question 13

what enzyme is needed for isomerization; glucose-6-phosphate into fructose-6-phosphate?

Answer 13

phosphoglucose isomerase- rearranges

Question 14

what enzyme is needed for phosphorylation of fructose-6-phosphate into fructose-1,6-bisphosphate?

Answer 14

phosphofructokinase-PFK *key rate limiting enzyme

Question 15

what does the enzyme aldolase do?

Answer 15

splits fructose-1,6-bisphosphate into DHAP and G3P

Question 16

which enzyme converts DHAP into another G3P?

Answer 16

triose phosphate isomerase

Question 17

G3P dehydrogenase does what?

Answer 17

oxidizes G3P into 1,3-bisphosphoglycerate (this happens twice)

Question 18

1,3-bisphosphogylcerate loses a phosphate with what enzyme and what is left?

Answer 18

phosphoglycerate kinase and 3-phosphoglycerate is left *this happens twice creating 2 ATP

Question 19

which enzyme moves the phosphate from 3-phosphoglycerate to 2-phosphoglycerate?

Answer 19

phosphoglycerate mutase

Question 20

2-phosphoglycerate into PEP (phosphoenolpyruvate) happens by what type of reaction and with what enzyme?

Answer 20

dehydration reaction and the enzyme is enolase

Question 21

phosphoenolpyrvuate PEP is a high energy molecule and wants to transfer its phosphate group, what enzyme does this?

Answer 21

pyruvate kinase

Question 22

any reaction within the cycle that is irreversible uses which type of enzyme?

Answer 22

kinase

Question 23

what are the key regulatory enzymes of glycolysis?

Answer 23

hexo/glucokinase
PFK
pyruvate kinase

Question 24

what is an isozyme?

Answer 24

different proteins that catalyze a reaction

Question 25

hexokinase has how many isozymes?

Answer 25

4

Question 26

hexokinase 1-3 are used for?

Answer 26

energy production

Question 27

hexokinase 4 (glucokinase) is used for?

Answer 27

blood glucose homeostasis

Question 28

hexokinase has high affinity for?

Answer 28

glucose (low Km)

Question 29

hexokinase is ______ by its product

Answer 29

inhibited

Question 30

glucokinase is found where?

Answer 30

liver and B cells of pancreas

Question 31

glucokinase is _______ by its product

Answer 31

NOT inhibited

Question 32

what is glucokinase stimulated by?

Answer 32

fructose and insulin

Question 33

glucokinase has a high Km which means?

Answer 33

it takes more reactant to make it go faster

Question 34

hexokinase is found where?

Answer 34

muscle

Question 35

what is the rate limiting step of glycolysis?

Answer 35

PFK-phosphofructokinase

Question 36

what 4 things inhibit PFK?

Answer 36

high energy charge decreased pH citrate-krebs cycle end products or waste products

Question 37

what is an allosteric enzyme?

Answer 37

ATP binds to the enzyme and decreases its activity

Question 38

is PFK an allosteric enzyme?

Answer 38

yes

Question 39

PFK-2 catalyzes what?

Answer 39

formation of fructose-2,6-bisphosphate in a different reaction

Question 40

what is the most potent activator of PFK-1

Answer 40

fructose-2,6-bisphosphate

Question 41

phosphorylation of fructose-6-phosphate by PFK-2 yields

Answer 41

fructose-2,6-bisphosphate

Question 42

what does fructose-2,6-bisphosphate do?

Answer 42

inhibits gluconeogenesis, stimulates glycolysis and is stimulated by insulin

Question 43

what decreases fructose-2,6-bisphosphate?

Answer 43

glucagon

Question 44

what does pyruvate kinase do?

Answer 44

catalyzes the 3rd irreversible step in glycolysis

Question 45

what inhibits pyruvate kinase?

Answer 45

increased alanine, ATP or pyruvate

Question 46

what stimulates pyruvate kinase?

Answer 46

increased ADP or PEP, fructose-1,6-bisphosphate

Question 47

when blood glucose is low which hormone is secreted?

Answer 47

glucagon