Enzymes Flashcards

1
Q

Acid Sphingomyelinase

A

breaks down sphingomyelin into ceramide and phosphorylcholine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Na/K ATPase

A

Na moves out, K moves in

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Sodium Calcium Exchanger

A

Na moves in, Ca moves out. Coupled with Na/K pump

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

GLUT 1

A

ubiquitous, high expression in RBCs and brain, high affinity for glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

GLUT 2

A

found in liver and pancreas, low glucose affinity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

GLUT 3

A

main transporter in neurons, high affinity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

GLUT 4

A

skeletal muscle, heart, and adipose, insulin dependent, lower affinity for glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Hexokinase/Glucokinase

A

Hexo-found every where, Gluco-found in liver, pancreatic B cells
Regulatory protein that traps glucose inside cells
Inhibited by Glucose 6P, glucagon, fructose6p
Promoted by Glucose, Fructose1P and Insulin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Phosphoglucose Isomerase

A

Isomerization of G6P to F6P

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

PFK-1

A

Rate limiting step, inhibit by ATP and citrate, F6P to F1,6BP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Aldolase A

A

Cleaves F1,6BP into DHAP and G3P

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Triose phosphate isomerase

A

Interconverts DHAP and G3P

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Glyceraldehyde 3P Dehydrogenase

A

phosphorylate G3P, creates NADH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Phosphoglycerate kinase

A

Conversion of 1,3BPG to 3PG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Pyruvate kinase

A

Formation of 2pyruvate, releases 2 ATP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How is glucokinase regulated?

A

F6P promotes translocation of GK to the nucleus, High glucose promotes GK release from GK-RP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How is PFK-1 regulated?

A

RATE LIMITING, F6P to F-1,6-BP, it is inhibited by ATP and citrate, it is activated by AMP and F2,6BP (formed by PFK-2), dephosphorylated form is favored by insulin, phosphorylated form is favored by glucagon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How is pyruvate kinase regulated?

A

PK catalyzes the conversion of PEP into pyruvate. It is activated by F1,6BP and insulin. It is inhibited by ATP, Ala, and glucagon, active form is dephosphorylated.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the four enzymes in gluconeogenesis that bypass the regulated enzymes of glycolysis?

A

Pyruvate carboxylase, PEP carboxykinase, F1,6BPase, Glucose 6-phosphatase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How is pyruvate carboxylase regulated?

A

Catalyzes the first step of of gluconeogenesis (pyruvate to OAA), it requires a biotin cofactor and is activated by acetyl CoA and cortisol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Mitochondrial malate dehydrogenase

A

OAA reduced to malate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Phosphoenolpyruvate carboxykinase (PEPCK)

A

decarboxylate and phosphorylate OAA to PEP, activated by cortisol, glucagon, and thyroxine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Fructose 1,6 Bisphosphatase

A

RATE LIMITING, F1,6BP to F6P, activated by cortisol and citrate, inhibited by AMP and F2,6BP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Glucose 6-Phosphatase

A

dephosphorylation to form glucose, only in liver, kidneys, SI, and pancreas. Activated by cortisol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Aldose reductase

A

reduces sorbitol to glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Sorbitol dehydrogenase

A

oxidizes sucrose to fructose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Glucose 1P Uridyltransferase

A

able to convert galactose 1-P to glucose 1-P by transferring UDP from UDP-glucose to galactose.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Lactase

A

Latate to glucose and galactose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Galactokinase

A

Converts galactose to galactose 1-P

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

G6P dehydrogenase

A

RATE LIMITING, Reduced glutathione to oxidized glutathione, produces 2 NADPH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Transketolase

A

TPP required as coenzyme, catalyzed transfer of 2C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Transaldose

A

catalyzes transfer of 3C segments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Phosphoglucomutase

A

isomerizes G6P to G1P

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

UDP-glucose pyrophosphorylase

A

G1P to UDP-Glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Glycogen synthase

A

RATE LIMITING, UDP-glucose to non reducing end of glycogen chain, dephospho form active, phospho form inactive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

glucosyl (4:6) transferase

A

reattaches glycogen chain broken off (after 11 residues) via a-1,6 bond

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

glycogen phosphorylase

A

RATE LIMITING in chain shortening, cleaves glucose residues off non-reducing end as G1P, uses vitamin B6, dephospho form is inactive, phospho form is active

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Debranching enzyme

A

transfer block of 3 of remaining 4 remaining branch to the main chain, then cleaves a-1,6 bond

39
Q

pyruvate kinase

A

dephosphorylates PEP, phosphorylates AdP

40
Q

phosphoglycerate kinase

A

dephosphorylate 1,3-BPG to 3-phosphoglycerate, phosphorylates ADP

41
Q

Creatine kinase

A

dephosphorylates phosphocreatine, phosphorylates ADP

42
Q

Pyruvate dehydrogenase complex

A

phosphorylated form is inactive, occurs in TPP, dephosphorylated is active

43
Q

Citrate synthase

A

OAA + Acetyl CoA = citrate

44
Q

aconitase

A

citrate to isocitrate, reversible

45
Q

isocitrate dehydrogenase

A

isocitrate to a-ketoglutarate, NADH released

46
Q

a-ketoglutarate dehydrogenase

A

a-ketoglutarate to succinyl coA, NADH released

47
Q

succinate thiokinase

A

Succinyl CoA to Succinate, GTP released

48
Q

Succinate dehydrogenase

A

succinate to fumarate, FADH2 released

49
Q

fumarase

A

fumarate to malate

50
Q

malate dehydrogenase

A

malate to OAA, releases NADH

51
Q

Complex 1

A

NADH dehydrogenase, inhibited by amytal, rotenone, myxothiazol, piercidin A; involves Fe-S, 4 protons pumped in

52
Q

Complex II

A

succinate dehydrogenase, inhibited by malate; involves Fe-S clusters, transfers 2 e-

53
Q

Complex III

A

cytochrome-c reductase, inhibited by antimycin; involves Fe-S clusters, 2 H into matrix

54
Q

Complex IV

A

cytochrome c oxidase, inhibited by Cyanide, CO, H2S; Cu clusters, 4H in, forms water

55
Q

Complex V

A

ATP synthase, inhibited by oligomycin, moves protons from one side of membrane to the other

56
Q

Citrate lyase

A

Citrate to acetyl coA and OAA

57
Q

Acetyl CoA Carboxylase

A

RATe LIMITING IN FA SYNTHESIS, adds CO2 to Acetyl CoA and creates malonyl coa, uses ATP and biotin , citrate upregulates, LCFAs inhibit, insulin activates, epi, glucagon, and AMP deactivate

58
Q

Fatty Acid Synthase compelx

A

composed of 2 identical dimers, 7 enzyme activities and an acyl carrier protein, each part participates in the condensation, reduction, dehydration, and reduction, production increased by insulin and glucocorticoid hormones, high carb/low fat diets increase, high fat diets lower, high PUFA suppresses

59
Q

Acyl CoA Desaturases

A

introduces double bonds in FA

60
Q

Hormone-sensitive lipase

A

TAG to DAG, inhibited by insulin, promoted by glucagon, epinephrine, and norepinephrine

61
Q

Lipoprotein lipase

A

DAG to MAG

62
Q

Monoacylglycerol lipase

A

MAG to glycerol

63
Q

Fatty acyl CoA synthetase

A

Fatty acid to Fatty acyl CoA

64
Q

CPT-1

A

Carnitine palmitoyltransferase I, fatty acyl CoA to Fatty acyl carnitine, malonyl CoA inhibits; RATE LIMITING

65
Q

CACT

A

Carnitine-acylcarnitine translocase, moves fatty acyl-carnitine into the cell and carnitine out of the cell

66
Q

CPT II

A

Carnitine palmitoyltransferase II, converts fatty acyl carnitine to Fatty acyl CoA

67
Q

Acyl CoA Dehydrogenase

A

oxidizes beta carbon to produce FADH2 and trans-enoyl-CoA in beta oxidation

68
Q

Enoyl CoA Hydratase

A

saturates alkene with water to form beta hydroxy acyl CoA

69
Q

B hydroxy acyl CoA dehydrogenase

A

beta hydroxy acyl CoA is oxidized to form ketoacyl CoA

70
Q

Acyl CoA acyl transferase

A

forms a ketone and shortens fatty acyl chain by 2C

71
Q

Propionyl CoA Carboxylase

A

carboxylates propionyl CoA to form methylmalonyl-CoA

72
Q

Methylmalonyl-CoA Mutase

A

genertes succinyl-CoA from methylmalonyl-CoA

73
Q

Exopeptidase

A

attacks at C- or N- terminus ends

74
Q

Endopeptidase

A

attacks within the protein at a specific site

75
Q

Enterokinase

A

activates trypsinogen

76
Q

Cystothionine B-synthase

A

with the use of PLP converts homocysteine to cystathionine

77
Q

Branched chain a-keto acid dehydrogenase complex

A

converts Leu to acetoacetate, deficiency results in MSUD

78
Q

Phenylalanine hydroxylase

A

Converts Phe to Tyr, deficiency results in PKU

79
Q

glutamate dehydrogenase

A

converts a-KG to Glu

80
Q

Glutamine synthetase

A

converts Glu to Gln

81
Q

Carbamoyl phosphate synthetase

A

Creates carbamoyl phosphate, Rate limiting step in urea cycle, up regulated by NAG

82
Q

PRPP Synthetase

A

used in purine de novo synthesis, utilizes ATP, activates ribose 5-phosphate, activated by phosphate levels, negatively regulated by GMP, AMP, and IMP

83
Q

Glutamine:phosphoribosyl pyrophosphate aminotransferase

A

PRPP to PRA, upregulated by PRPP, down regulated by purine nucleotides

84
Q

adenylosuccinate synthetase

A

IMP to AMP, negatively controled by AMP

85
Q

IMP Dehydrogenase

A

IMP to XMP, negatively controlled by GMP

86
Q

aspartate transcarbamoylase

A

carbmoyl phosphate to carbamoyl aspartate, RAME LIMITING step in pyrimidine synthesis

87
Q

carbamoyl phosphate synthetase II

A

activated by PRPP and inhibited by UTP, Gln to carbamoyl phosphate

88
Q

UMP synthase

A

Orotate (+PRPP) to OMP, defect results in orotic aciduria

89
Q

Adenosine deaminase

A

Irreversible hydrolytic deamination of adenosine to inosine

90
Q

Xanthine oxidase

A

Hypoxanthine to xanthine to uric acid

91
Q

Adenine phosphoribosyltransferase

A

generates AMP from adenine and PRPP

92
Q

Hypoxanthine-guanine phosphoribosyltransferase

A

HGPRT, generates GMP or IMP

93
Q

AMP-activated protein kinase

A

cellular energy sensor, activated by low ATP, phosphorylates targets that control cellular energy production and consumption