Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biochem > Cholesterol > Flashcards

Cholesterol Flashcards

1
Q

Enzyme that catalyzes:
Cholesterol → Cholesteryl ester

A

Acyl CoA cholesterol acyltransferase (ACAT)

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

Vitamin D3 is formed endogenously in skin from UV exposure to this

A

Cholesterol

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

Conditions of vitamin D deficiency

A

Childhood Rickets
Adult osteomalacia

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

Childhood Rickets and Adult osteomalacia involve a deficiency in

A

Vitamin D

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

Molecule that maintains membrane fluidity

A

Cholesterol

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

Quantitatively most important product of cholesterol

A

Bile acids

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

Vitamin D is converted to a hormone that enhances intestinal absorption of this

A

Ca2+

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

Enzyme that catalyzes:
Cholesterol → 7α-hydroxycholesterol

A

7α-hydroxylase

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

Regulation of 7α-hydroxylase

A

Negative feedback by bile acids

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

Location where bile salts are synthesized

A

Liver

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

Location where bile salts are stored

A

Gall bladder

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

Bile acids are reabsorbed here for recirculation into what

A

Reabsorbed into GI tract for recirculation to the liver (enterohepatic recirculation)

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

Type of fiber that decreases bile acid reabsorption and helps reduce cholesterol levels

A

Soluble fiber

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

Tissues that make cholesterol

A

Most tissues
Mainly liver, adrenals, gonads, intestine, placenta

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

Enzyme that catalyzes:
Acetyl CoA → Acetoacetyl CoA

A

Thiolase

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

Source of cytoplasmic acetyl CoA

A

Citrate

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

Enzyme that catalyzes:
acetyl CoA + acetoacetyl CoA → Beta-hydroxy-beta-methyl glutaryl CoA (HMG CoA)

A

Cytosolic HMG CoA synthase

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

Form of HMG CoA synthase that is used to make ketone bodies

A

Mitochondrial

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

Form of HMG CoA synthase that is used to make cholesterol

A

Cytosolic

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

Enzyme that catalyzes:
HMG CoA + 2 NADPH → mevalonate + NADP+

A

HMG CoA reductase

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

Subcellular location of HMG CoA reductase

A

ER membrane

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

Type of regulation of HMG CoA reductase

A

Transcriptional control
Post-transcriptional control via proteolysis/degradation
Phosphorylation

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

Binds to steroid response element (SRE) of HMG CoA reductase gene and turns on transcription when cholesterol levels are low

A

SREBP DNA-binding domain

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

ER membrane protein associated with SCAP (cleavage activating protein)

A

SREBP

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

In this sterol concentration, sterol binds to SCAP and inactivates it

A

High [sterol]

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

In this sterol concentration, SCAP-SREBP is transported to the Golgi

A

Low [sterol]

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

Is HMG CoA reductase active or inactive when phosphorylated?

A

Inactive

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

What results in dephosphorylation of HMG CoA reductase, thus activating it?

A

Insulin

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

What results in phosphorylation of HMG CoA reductase, thus inactivating it?

A

Glucagon and sterols

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

Product of HMG CoA reductase

A

Mevalonate

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

Lipoprotein that transports dietary fat from the intestine

A

Chylomicrons

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

Least dense lipoprotein

A

Chylomicron

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

Chylomicrons are mostly made up of this

A

Fat

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

Milky or turbid appearance of centrifuged blood indicates this

A

Excess chylomicrons

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

Chylomicrons are synthesized here

A

Intestinal epithelial cells - in ER, secreted from golgi

36
Q

Protein that adds lipid during the synthesis of chylomicrons

A

Microsomal transfer protein (MTP)

37
Q

Condition caused by defect in microsomal transfer protein (MTP)
Involves decreased levels of chylomicrons

A

Abetalipoproteinemia

38
Q

Chylomicrons enter the blood through this

A

Thoracic duct

39
Q

Enzyme that hydrolyzes the TGs of the chylomicron

A

Lipoprotein lipase (LPL)

40
Q

Insulin has what effect on LPL synthesis in adipose?

A

Stimulates

41
Q

Apolipoprotein CII has what effect on LPL?

A

Activates

42
Q

An ApoCII deficiency would lead to high levels of this

A

Triglycerides

43
Q

Fatty acids are transported in the blood bound to this

A

Albumin

44
Q

An ApoE deficiency would result in high levels of this

A

Chylomicron remnants

45
Q

Lipoprotein that transport endogenous fat from the liver

A

VLDLs

46
Q

VLDLs are synthesized here

A

Liver

47
Q

VLDLs are secreted via this

A

Hepatic veins

48
Q

Structural apolipoprotein of VLDLs

A

ApoB-100

49
Q

Enzyme that further hydrolyzes IDL to LDL along with LPL

A

HTGL-hepatic triglyceride lipase (HTGL)

50
Q

Excess LDL taken up by macrophages forms this

A

Plaque

51
Q

Result of macrophages consuming excess modified (oxidized) lipoprotein

A

Become foam cells

52
Q

Foam cells are formed from macrophages consuming excess of this

A

Lipoprotein

53
Q

Is the solubility of cholesterol high or low?

A

Low, which leads to accumulation (plaques) in blood vessels

54
Q

Condition due to inability to release cholesterol from lysosome

A

Niemann-Pick Type C disease

55
Q

Lipoprotein that deliver cholesterol to liver and tissues with large cholesterol needs (adrenals, sex glands)

A

LDLs

56
Q

Lipoprotein with the highest proportion of cholesterol

A

LDLs

57
Q

Lipoprotein that transport cholesterol from membranes in tissues back to liver for reprocessing

A

HDLs

58
Q

Lipoprotein that involves reverse cholesterol transport

A

HDLs

59
Q

Lipoprotein with the highest proportion of protein

A

HDLs

60
Q

HDLs are synthesized here

A

Mainly liver and intestine

61
Q

Mature HDL is called

A

HDL3

62
Q

High cholesterol HDL is called

A

HDL2

63
Q

ATPase that moves cholesterol from inner leaflet of plasma membrane to outer leaflet

A

ABC1

64
Q

2 enzymes required for HDL to pick up cholesterol from extrahepatic cells

A

LCAT: lecithin cholesterol acyl transferase
CETP: cholesterol ester transfer protein

65
Q

HDL is taken up by this receptor
Does not involve endocytosis

A

SR-B1 receptor

66
Q

Lipoprotein that is vasculoprotective

A

HDLs

67
Q

Apoprotein involves in the assembly and secretion of chylomicrons from small bowel

A

ApoB-48

68
Q

Apoprotein that is primarily from the intestine

A

ApoB-48

69
Q

Apoprotein involved in VLDL assembly and secretion
Structured protein of VLDL, IDL, and LDL ligand for LDL receptor

A

ApoB-100

70
Q

Apoprotein that is a cofactor activator of lipoprotein lipase (LPL)

A

ApoC-II

71
Q

Apoprotein that is a ligand for binding of several lipoproteins to the LDL receptor, to the LDL receptor-related protein (LRP) and possibly to a separate apoE receptor

A

ApoE

72
Q

Apoprotein with lipoprotein distribution of:
Chylomicrons

A

ApoB-48

73
Q

Apoprotein with lipoprotein distribution of:
VLDL, IDL, LDL

A

ApoB-100

74
Q

Apoprotein with lipoprotein distribution of:
Chylomicrons, VLDL, IDL, HDL

A

ApoC-II

75
Q

Apoprotein with lipoprotein distribution of:
Chylomicron remnants, VLDL, IDL, HDL

A

ApoE

76
Q

3 possible causes of fat malabsorption

A

Pancreatic failure
Lack of bile salts
Intestinal diseases

77
Q

Lack of bile salts can have this effect on fat absorption

A

decreased

78
Q

Fat malabsorption has this effect on stools

A

Steatorrhea (bulky fatty stools)

79
Q

Product by RNA editing of the ApoB-100 gene

A

ApoB-48

80
Q

RNA editing of ApoB-100 to ApoB-48 takes place here

A

Intestine

81
Q

Lipoproteinemia caused by deficiency in apoC-II or defective lipoprotein lipase

A

Type I hyperlipoproteinemia
(Familial hyperchylomicronemia)

82
Q

Lipoproteinemia caused by partially or completely defective LDL receptor, or ApoB-100 deficiency

A

Type IIa and IIb hyperlipoproteinemia
(Familial hypercholesterolemia)

83
Q

Lipoproteinemia caused by defect in ApoE

A

Type III hyperlipoproteinemia
(Familial dysbetalipoproteinemia)

84
Q

Lipoproteinemia caused by reduction in the catabolism of VLDLs or increase in their synthesis

A

Type IV hyperlipoproteinemia
(Familial hypertriglyceridemia)

85
Q

Lipoproteinemia caused by defect in transporter that supports cholesterol pickup by nascent HDLs

A

Tangier disease

86
Q

Lipoproteinemia caused by accelerated catabolism of ApoA-I and ApoA-II

A

Hypoalphalipoproteinemia

87
Q

Binds bile acids and prevents their reuptake in the enterohepatic circulation
Results in lowered cholesterol levels

A

Cholestyramine

Biochem (21 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions