Unit I Glycolysis

Question 1

What does glycolysis mean?

Answer 1

carbohydrate breakdown

Question 2

Is glycolysis anerobic or aerobic?

Answer 2

anerobic

Question 3

How many pyruvates are produced from 1 glucose molecule?

Answer 3

2

Question 4

Besides pyruvate, what other key products are made from glycolysis?

Answer 4

ATP and NADH

Question 5

What is fast glycolysis?

Answer 5

pyruvate is converted to lactic acid and alanine

Question 6

What is slow glycolysis?

Answer 6

pyruvate is sent to mitochondria and used in aerobic metabolism instead

Question 7

Glycolysis yields precursors for which aerobic systems?

Answer 7

Krebs and ETS

Question 8

Where in the cell does glycolysis take place?

Answer 8

the cytosol

Question 9

To enter krebs, the product pyruvate from glycolysis, must first become what?

Answer 9

first it’s sent to the mitochondria and then converted to acetyl-CoA

Question 10

What is the fate of glucose in glycolysis?

Answer 10

to become ATP or a precursor for aerobic metabolism

Question 11

What is the prep step in glycolysis?

Answer 11

phophorylation glucose

Question 12

Phosphorylating glucose does what?

Answer 12

it traps it in the cell so it cant get out

Question 13

The product of phosphorylating glucose is what?

Answer 13

glucose-6-phosphate

Question 14

What is the enzyme that helps produce G-6-P?

Answer 14

hexokinase

Question 15

What is coupled with hexokinase in the making of G-6-P?

Answer 15

ATP

Question 16

Is the reaction of glucose to G-6-P endergonic or exergonic?

Answer 16

endergonic

Question 17

Is glucose to G-6-P reversible or irreversible?

Answer 17

irreversible

Question 18

G-6-P to fructose-6-phosphate is catalyzed by which enzyme?

Answer 18

phosphoglucose isomerase

Question 19

is G-6-P to F-6-P irreversible?

Answer 19

yes

Question 20

F-6-P to Fructose-1,6-bisphosphate is catalyzed by which enzyme?

Answer 20

phosphofructokinase “PFK”

Question 21

What is PFK coupled with in the phosphorylation of F-6-P?

Answer 21

ATP

Question 22

Is the phosphorylation of F-6-P a key rate limiting step?

Answer 22

yes

Question 23

What are the rate limiting steps of the first half of glycolysis?

Answer 23

glucose to G-6-P and F-6-P to F-1,6-BP

Question 24

What is the purpose of glycolysis?

Answer 24

to make ATP, pyruvate, and precursors for aerobic metabolism

Question 25

What are the two products of splitting F-1,6-BP?

Answer 25

Dihydroxyacetone phosphate and Glyceraldehyde-3-Phosphate

Question 26

What catalyzes the reaction of F-1,6-BP to DHAP and G-3-P?

Answer 26

aldolase

Question 27

Is F-1,6-BP to DHAP and G-3-P a reversible reaction?

Answer 27

yes

Question 28

DHAP gets converted to what in glycolysis?

Answer 28

G-3-P

Question 29

what reacts with DHAP to make G3P?

Answer 29

triose phosphate isomerase

Question 30

Is the isomerization of DHAP a reversible reaction?

Answer 30

yes

Question 31

How many pyruvates does glycolysis make again?

Answer 31

2

Question 32

In the redox reaction of G-3-P what is the product?

Answer 32

1,3-bisphosphoglycerate

Question 33

What is the enzyme in the redox reaction of G-3-P?

Answer 33

G3P-dehydrogenase

Question 34

What catalyzes the reaction of 1,3-BPG to 3-PG

Answer 34

phosphoglycerate kinase

Question 35

What is 3-PG converted to in glycolysis?

Answer 35

2-phosphoglycerate

Question 36

What catalyzes the reaction of 3-PG to 2-PG?

Answer 36

phosphoglycerate mutase

Question 37

2-PG is catalyzed to phosphoenolpyruvate by what enzyme?

Answer 37

enolase

Question 38

Is the dehydration of 2-PG a reversible reaction?

Answer 38

yes

Question 39

PPE is catalyzed to pyruvate by what enzyme?

Answer 39

pyruvate kinase

Question 40

What is the third and final irreversible reaction in glycolysis?

Answer 40

PPE to pyruvate

Question 41

How many ATP are yielded in glycolysis?

Answer 41

two

Question 42

List the key regulatory enzymes of glycolysis

Answer 42

hexokinase, PFK, and Pyruvate kinase

Question 43

Is hexokinase an isozyme?

Answer 43

yes

Question 44

What is an isozyme?

Answer 44

different version of the enzyme

Question 45

Hexokinase I-III is for

Answer 45

energy production

Question 46

Hexokinase IV is for

Answer 46

blood glucose homeostasis

Question 47

What is another name for hexokinase IV?

Answer 47

glucokinase

Question 48

Which type(s) of hexokinase have a high affinity for glucose? (low Km)

Answer 48

Hexokinase I-III

Question 49

Hexokinase I-III is inhibited by what?

Answer 49

by its product G-6-P

Question 50

Where is glucokinase located?

Answer 50

in the liver and beta cells of the pancreas

Question 51

Does glucokinase have a high or? low affinity for glucose?

Answer 51

low affinity but a high Km

Question 52

What is the purpose of glucokinase having a lower affinity?

Answer 52

so that the brain and muscle can capture glucose more easily

Question 53

Is glucokinase inhibited by its product?

Answer 53

no it is not

Question 54

What is glucokinase stimulated by in the liver?

Answer 54

insulin and fructose

Question 55

What is hexokinase stimulated by in the muscle?

Answer 55

glucose

Question 56

When an excess of glucose is present in the liver what does glucokinase do?

Answer 56

increases uptake and converts it to fat and glycogen

Question 57

Inhibition of PFK would also cause the inhibition of?

Answer 57

hexokinase

Question 58

What is the rate limiting step of glycolysis?

Answer 58

PFK (F6P to F-1,6-BP)

Question 59

When ATP binds to PFK, what does it do?

Answer 59

ATP will decrease PFK's activity

Question 60

Would a high energy charge inhibit or stimulate PFK?

Answer 60

It would inhibit

Question 61

What would have to happen to pH to inhibit PFK?

Answer 61

it would have to significantly decrease

Question 62

An intermediate of Krebs that also inhibits PFK

Answer 62

citrate

Question 63

What is an allosteric enzyme?

Answer 63

an enzyme with many active sites

Question 64

Would waste or end products inhibit or stimulate glycolysis?

Answer 64

inhibit

Question 65

What alternate pathways can G6P be used in?

Answer 65

glycogen synthesis or pentose phosphate pathway

Question 66

Describe PFK-1

Answer 66

catalyzes formation of F-1,6-BP and is used in glycolysis

Question 67

Describe PFK-2

Answer 67

catalyzes formation of F-2,6-BP in a different pathway

Question 68

What is the most potent activator of PFK-1?

Answer 68

F-2,6-BP

Question 69

What would yield F-2,6-BP?

Answer 69

the phosphorylation of F6P by PFK-2

Question 70

What stimulates PFK-2?

Answer 70

insulin

Question 71

What does PFK-2 stimulate?

Answer 71

glycolysis and PFK in the liver

Question 72

What does PFK-2 inhibit?

Answer 72

gluconeogenesis

Question 73

What decreases F-2,6-BP?

Answer 73

glucagon

Question 74

What is the enzyme of the third irreversible step in glycolysis?

Answer 74

pyruvate kinase

Question 75

what is pyruvate kinase inhibited by?

Answer 75

alanine or ATP

Question 76

What would stimulate pyruvate kinase (PK)?

Answer 76

F-1,6-BP

Question 77

In the liver, phosphorylation of PK would?

Answer 77

inactivate liver PK

Question 78

In the liver, what reactivates PK?

Answer 78

dephosphorylation

Question 79

PFK is linked to PK through a?

Answer 79

feedforward link

Question 80

What are the fates of pyruvate from glycolysis?

Answer 80

alanine, lactate,and aerobic metabolism

Question 81

What must happen to pyruvate to become alanine?

Answer 81

It must gain an amine group

Question 82

What converts pyruvate to lactate?

Answer 82

lactate dehydrogenase

Question 83

What is lactate dehydrogenase coupled with in the conversion of pyruvate to lactate?

Answer 83

NADH

Question 84

What happens when pyruvate accumulates in an exercising muscle?

Answer 84

it is converted to lactate

Question 85

What does the presence of lactate do to glycolysis?

Answer 85

It speeds it up

Question 86

The increase of NAD from the production of lactate would stimulate or inhibit G3P dehydrogenase?

Answer 86

stimulate

Question 87

A large amount of lactate would stimulate or inhibit glycolysis?

Answer 87

inhibit

Question 88

A significant drop in pH inhibits or stimulates PFK?

Answer 88

inhibits

Question 89

Where is fructose phosphorylated to be used in glycolysis?

Answer 89

in the muscle and kidney

Question 90

When fructose is phosphorylated in the muscle and kidney what is produced?

Answer 90

F6P

Question 91

What phosphorylates frucotse to F6P in the muscle and kidney?

Answer 91

hexokinase

Question 92

What is coupled with hexokinase to convert Fructose to F6P in the muscle and kidney?

Answer 92

ATP

Question 93

When would fructose be used in glycolysis over glucose when in the muscle and kidney?

Answer 93

when there is a large amount of frutcose

Question 94

Why is glucose used before fructose?

Answer 94

because of hexokinase's affinity for glucose

Question 95

In the liver, what converts fructose to F1P?

Answer 95

fructokinase

Question 96

What is coupled with fructokinase in the conversion of fructose to F1P?

Answer 96

ATP

Question 97

In the liver, what converts F1P to Glyceraldehyde and DHAP?

Answer 97

F-1P-aldolase

Question 98

In the liver, what converts glyceraldehyde to G3P?

Answer 98

triose kinase

Question 99

In the liver, what converts DHAP to G3P?

Answer 99

triose phosphate isomerase

Question 100

In the liver, what is the key entry point into glycolysis?

Answer 100

G3P

Question 101

For galactose entry into glycolysis, what is most important?

Answer 101

that it be converted into G6P