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Flashcards in Biochem II Deck (96):
1

What is insulin addressing: the BG or energy needs of cells?

BG

2

What is the only source of energy of RBCs?

Glycolysis

3

What is the fuel utilization during the well fed state for the liver?

Glucose, AAs

4

What is the fuel utilization during the well fed state for the muscles?

Glucose

5

What is the fuel utilization during the well fed state for the heart?

FAs

6

What is the fuel utilization during the well fed state for the adipose tissue?

Glucose

7

What is the fuel utilization during the well fed state for the brain?

Glucose

8

What is the fuel utilization during the well fed state for the RBCs?

Glucose

9

What is the fuel utilization during the fasting state for the liver?

FAs

10

What is the fuel utilization during the fasting state for the muscle?

FAs, ketones

11

What is the fuel utilization during the fasting state for the heart?

FAs, ketones

12

What is the fuel utilization during the fasting state for the adipose tissue?

FAs

13

What is the fuel utilization during the fasting state for the Brain?

Glucose (ketones in the late fast)

14

What is the fuel utilization during the fasting state for the RBCs?

Glucose

15

What is the kcal/g for: carbs?

4

16

What is the kcal/g for: fat?

9

17

What is the kcal/g for: EtOH?

7

18

What are the two types of amylase?

SAlivary and pancreatic

19

What are the three different intestinal disaccharidases?

-Lactase
-Sucrase
-Maltase

20

What is the enzyme that is defective in MODY?

Glucokinase

21

What is the transporter that transports glucose from the intestines?

SGLT1/2

22

What is the GLUT that is activated by insulin?

GLUT4

23

What is the GLUT5 activity?

Passive uptake of fructose

24

True or false: fructose is not regulated by insulin, or any other hormone

True

25

Do GLUTs 1-4 utilize passive or active transport?

Passive

26

What is the difference between hexokinase and glucokinase in terms of: location?

Hexokinase is in msot tissues, except liver

Glucokinase - only in liver and beta cells of pancrease

27

What is the difference between hexokinase and glucokinase in terms of: Km?

Low for hexokinase (high affinity)

High for glucokinase (low affinity)

28

What is the difference between hexokinase and glucokinase in terms of: Vmax?

Low for hexokinase (low capacity)

High for glucokinase (high capacity)

29

What is the difference between hexokinase and glucokinase in terms of: inducibility by insulin

Hexokinase is not affected by insulin, while glucokinase is not

30

What is the difference between hexokinase and glucokinase in terms of: Feedback inhibition by G6P

Hexokinase is inhibited
Glucokinase is not

31

What is the main regulated step of glycolysis? What activates and inhibits it?

-Phosphofructokinase is activated via F2,6BP
-Inhibits by ATP, citrate, pH

32

What is DHAP used for in glycolysis?

TAG synthesis

33

Glycolysis defects produces what diseases?

Hemolytic anemias

34

What is the MOA of arsenate?

Inhibits ATP production by glycolysis

35

What happens to galactose?

Converted to glucose

36

What is the cause of galactosemia? S/sx?

Defect in galactose metabolism leads to jaundice, cataracts, and liver damage early in life

37

What are the two ways in which fructose is degraded?

-Hexokinase side rxn
-Fructokinase in the liver produces F1P, which is degraded by adolase B

38

What is the cause of benign fructosuria?

Defect in fructokinase

39

What happens with aldolase B deficiency?

Hereditary fructose intolerance
-Jaundice
-Hypoglycemia
-Hepatomegaly

40

What is the overall rxn with pyruvate dehydrogenase? Where in the cell is it?

-Produces acetyl-CoA from pyruvate
-mitochondria

41

What are the 5 cofactors that are needed for the Pyruvate dehydrogenase complex?

NAD (niacin)
FAD (pantothenate)
B1
B5

42

What activates the Pyruvate dehydrogenase complex? Inhibits?

-Insulin activates
-Repressed by acetyl-CoA

43

What is glycogenin?

Enzyme that attaches UDP-glucose to Y residues

44

What is the effect of insulin on liver and muscle glycogen synthase?

Activates

45

What inhibits hepatic and muscle glycogen synthase respectively?

Hepatic = glucagon and epi

Muscle = epi

46

What activates hepatic and muscle glycogen phosphorylase respectively?

Hepatic = glucagon and epi

Muscle = epi

47

What inhibits hepatic and muscle glycogen synthase respectively?

Hepatic = insulin

Muscle = insulin

48

What is the enzymatic defect in type I GSD?

Glucose-6-phosphate dehydrogenase

49

What is the enzymatic defect in type II GSD?

lysosomal glucosidase

50

What is the enzymatic defect in type III GSD?

Debranching enzyme

51

What is the enzymatic defect in type IV GSD?

Branching enzyme

52

What is the enzymatic defect in type V GSD?

Muscle phosphorylase

53

What is the enzymatic defect in type VI GSD?

Liver phosphorylase

54

What is the cause of death with Pompe's disease?

LVH

55

What is the general structure of proteoglycans?

Long Hyaluronic acid with side branches of Protein cores, with many attached glycosaminoglycans

56

What is the defective enzyme, accumulated products and s/sx of: Hurler's disease?

-Dermatan sulfate / heparine sulfate
-alpha-iduronidase
-Skeletal abnormalities, MR

57

What is the defective enzyme, accumulated products and s/sx of: Hunter syndrome

Dermatan sulfate
Heparin sulfate

-Skeletal abnormalities and MR

58

What is the defective enzyme, accumulated products and s/sx of: Sanfiloppo's disease

Heparine sulfate
MR

59

What is the inheritance pattern of Hunter syndrome, hurler syndrome, and sanfilippo>

Hunter = XLR
Hurler's = AR
Sanfilippo = AR

60

What are the three molecules that are used as substrates for gluconeogenesis?

-Glycerol P
-Lactate
-Glucogenic amino acids

61

What is the rate limiting step of gluconeogenesis?

Pyruvate carboxylase

62

Acetyl-CoA regulates what parts of gluconeogenesis?

Carboxylase (+) and dehydrogenase (-)

63

Gluconeogenesis depends on what molecule in particular?

NAD+

64

Why does EtOH inhibit gluconeogenesis?

Lowers NAD+

65

What is the inheritance pattern of G6PD deficiency?

AR

66

What type of anemia is produced with G6PD deficiency?

Hemolytic

67

What are the three major roles of the PPP?

-liver
-PMNs = NADPH oxidase
-RBCs = defend against oxidative stress

68

What is the RBC inclusion for G6PD Deficiency?

Heinz bodies

69

What are the essential FAs?

Linoleate (9, 12)

70

Where does the synthesis of lipids begin?

Export of Acetyl-COa into the cytosol

71

What is the key reaction for lipids in the well fed state?

Acetyl-CoA carboxylase

72

What inhibits lipid import into the mitochondria?

Malonyl-CoA

73

What is the activating step of FA synthesis?

Acyl CoA synthetase

74

Why does EtOH lead to fatty liver changes?

Ethanol metabolism produces NADH, which inhibits the citric acid cycle

75

What is the role of albumin in lipid transport?

Transports in blood

76

What is the function of ApoA?

Lipid uptake into LPs

77

What is the function of ApoB?

Structural support (b100 on LDL, B48 on chylomicrons)

78

What is the function of ApoC?

For lipid release from LPs (activates LPL)

79

What is the function of ApoE?

For removal of LPs via interaction with liver receptor

80

What are the lipoproteins in chylomicrons?

b48
C
E

81

What are the lipoproteins in VLDL?

B100
C
E

82

What is the general role of LDL?

pick up cholesterol, give TAGs

83

What is the protein that extracts lipids from cells for pick up by LPs?

ABCA-1

84

What is the protein that is involved in transferring cholesterol between LPs?

Cholesteryl ester transfer protein (CTEP)

85

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86

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87

LDL oxidation can be prevented by what vitamin?

E

88

What is the backbone of HDL particles?

Apo A

89

What is familial hyperlipidemia?

Elevated LDL and cholesterol 2/2 LDL receptor deficiency

90

What is abetalipoproteinemia?

No ApoB100/48, causes lipid accumulation in enterocytes and liver, leading to extremely low serum lipids

91

What is the key step in cholesterol synthesis?

HMG-CoA

92

What is the cholesterol intermediate needed for CoQ?

Farnesylation

93

What is the shuttle utilized to transport FAs into the mitochondria?

Carnitine shuttle

94

What is the key step in FA catabolism? How is it regulated?

Carnitine shuttle across the inner mitochondrial membrane

Regulated by malonyl CoA

95

What is the most common defect in FA metabolism?

Acyl-coa dehydrogenase

96

Odd chain FAs produce what?

propionyl-CoA