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Flashcards in Glycolysis Deck (77)
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1
Q

If glucose enters cells by facilitated diffusion, it will leave the same way, so how do you keep it there?

A

phosphorylation

2
Q

What term describes sets of enzymes that have different amino acid sequences but catalyze the same reaction?

A

isoenzymes

3
Q
Glucokinase
	A. has a Km lower than the normal blood glucose 	concentration.
	B. has glucose-6—phosphatase activity.
	C. is found in muscle.
	D. is inhibited by glucose-6-phosphate.
	E. none of the above.
A

E. none of the above.

4
Q

Red cells have lactate dehydrogenase primarily so that

A

they can regenerate NAD+ to keep glycolysis going

5
Q

when liver PFK 2 is targeted by insulin, it will

A

become a fructose- 2,6- BP synthetase

6
Q

Glucose is broken down via ______ for energy

A

glycolysis

7
Q

Glycolysis overview

A

breakdown of glucose to pyruvate under aerobic condition

8
Q

under anaerobic conditions, Glycolysis

A

produces lactate

9
Q

glucose enters the cell via

A

facilitated diffusion

10
Q

How is glucose kept in the cell?

A

phosphorylation

11
Q

addition of phosphate makes glucose

A

charged

12
Q

kinase that is specific for glucose

A

glucokinase

13
Q

kinase that can phosphorylate glucose and other hexes

A

hexokinase

14
Q

hexokinase is inhibited by

A

its product, G6P

15
Q

glucokinase is not inhibited by G6P products which allows

A

liver to act as a glucose dump

16
Q

glucokinase has a ___ km which means

A

high Km which means it has low affinity ofr glucose thus it is hard to get saturated and can bind to glucose of of the blood

17
Q

Hexokinase has a ____ km which means

A

low km, which means that it has high affinity for glucose

18
Q

not associated with obesity or high lipid levels; patients still make insulin

A

Type II Diabetes

19
Q

MODY is associated with

A

mutation in Glucokinase gene

20
Q

what happens to MODy in the liver

A

it cannot binds properly bind to glucose

21
Q

MODY is also associated with genes for transcription factors that

A

promote insulin release

22
Q

Because Mutant Glucokinase cannot take up glucose to metabolize leading to

A

reduced glycolysis leading to lower insulin release

23
Q

ATP causes closing of ______ channel leading to _________ via rush of ______ which leads to depolarization and _____ release

A

ATP causes closing of K+ channel leading to depolarization via rush of calcium which leads to depolarization and insulin release

24
Q

Glucose is brought into _________ via Glucokinase and undergoes _____ to create ATP

A

Glucose is brought into Beta-pancreatic cells via glucokinase and undergoes glycolysis to create ATP

25
Q

_____ is very important in RBCs

A

Glycolysis

26
Q

Why doe RBCs depend on glycolysis for ATP production

A

lack of mitochondria

27
Q

glycolysis provides muscle

A

energy for exercise

28
Q

initial exercise uses the ________ glycolysis

A

anaerobic

29
Q

as you continue to exercise, you switch to the _______ energy system as the tissue oxygenates, which still uses glycolysis but adds the ________

A

As you continue to exercise, you switch to the aerobic energy system as the tissue oxygenates, which still uses glycolysis but adds the TCA cycle

30
Q

_____ or _______, glycolysis produces energy in the form of ATP

A

Aerobically or anaerobically

31
Q

glycolysis occurs in the

A

cytoplasm

32
Q

Glucose is phosphorylated to ______ by ______ then converted to _________

A

Glucose is phosphorylated to G6P by hexokinase/glucokinase, then converted to F6P

33
Q

F6P is ________ to make ______ which is broken down to _____ and ______, which can be interconverted

A

F6P is phosphorylated to make F-1,6-bisP which is broken down to G3P and DHAP, which can be interconverted

34
Q

what happens in the first phases of glycolysis?

A

2 ATP are used to generate 2 phosphorylated 3 carbon intermediate

35
Q

what must be made to generate ATP?

A

high energy phosphate

36
Q

which enzyme shows negative cooperativity?

A

Glyceraldehyde 3-Phosphate Dehydrogenase

37
Q

what do you need to keep glycolysis going?

A

NAD+

38
Q

enzyme resists the loss of ____ that occurs when glycolysis is proceeding at a _____ rate as in _______ muscle

A

Enzyme resists the loss of NAD+ that occurs when glycolysis is proceeding at a high rate as in anaerobic muscle

39
Q

reversibly accepts 2e- and 1H+ from the subtrate

A

NAD+

40
Q

Rxn of NAD+—>NADH is a

A

redox rxn, beucase NAD+ is reduced and the substrate is oxidized

41
Q

cells are set up to have a ____________ as it wants to have a ready supply of _______ for biological oxidation

A

cells is set up to have a high NAD+/NADH ratio as it wants to have a ready supply of NAD+ for biological oxidation

42
Q

Niacin is derived from

A

vitamin B3 and synthesized also from tryptohan

43
Q

deficient in niacin leads to

A

Pellagra

44
Q

Pellagra D3 involves

A

dermatitis, diarrhea and dementia

45
Q

D4 of pellagra?

A

die

46
Q

action of enolase and results in

A

creates double bond adjacent to phosphate making high energy phosphoenolpyruvate

47
Q

Pyruvate kinase generate

A

ATP and turns PEP into pyruvate

48
Q

1,3 BPG generates

A

2 molecules of ATP

49
Q

Net yield of ATP in glycolysis

A

2 ATP; 2 consumed and 4 made

50
Q

lactate DH regenerates

A

NAD+

51
Q

what happens if you run out of NAD+ during anaerobic conditions?

A

Cannot use ETC or TCA to regenerate NAD+

52
Q

creates some important metabolites for other pathways

A

glycolysis

53
Q

three regulated enzymes in glycolysis

A

hexokinase, pFK 1, pyruvate kinase

54
Q

Hexokinase is inhibited by

A

product

55
Q

what is the key regulated step in glycolysis

A

PFK1

56
Q

PFK 1 inhibitor

A

ATP

57
Q

PFK1 promoter

A

AMP

58
Q

Allosteric inhibitor of PFK1

A

citrate

59
Q

PFK1 is strongly affected by

A

positive regulator F-2,6-BP

60
Q

Pyruvate kinase has feedforward regulation by

A

F-1,6-BP

61
Q

Pyruvate kinase is inhibited by

A

phosphorylation and alanine

62
Q

enzyme that controls F-2,6-BP levels

A

PFK2

63
Q

PFK2 activates

A

PFK1 and glycolysis by making F-2,6-BP

64
Q

PFK2 is inhibited by and what happens?

A

inhibited by glucagon, leading to its phosphorylation and degrading F-2,6-BP which reduces activity of PFK2 and glycolysis

65
Q

Insulin activity to PFK2

A

drives the dephosphorylation of PFK2 and stimulates synthesis of F-2,6-BP which stimulates PFK1 and glycolysis

66
Q

insulin action towards rate of glycolysis

A

increases

67
Q

2-F-deoxyglucose targets

A

hexokinase

68
Q

2-F-deoxyglucose is a

A

competitive inhibitor of hexokinase rxn.

69
Q

2-F-deoxyglucose can be used

A

in PET imaging to find metastasis

70
Q

targets glyceraldehyde 3 Phosphate DH

A

arsenate

71
Q

targets enolase

A

fluoride

72
Q

glycogen storage disease

A

Tauri’s dx

73
Q

Pyruvate kinase has 4 isozymes

A

M1, M2, L and R

74
Q

R-Pyruvate kinase is found only in

A

red blood cells

75
Q

Tauris tx

A

high protein diet

76
Q

Glycolytic anemia

A

faulty R-pyruvate kinase

77
Q

muscle has _____ PFK isozyme while RBC’s have _____ isozyme

A

muscle has 1 and RBC’s has 3