Lipids and Lipoproteins Flashcards

1
Q

List three disorders of lipid metabolism.

A

Coronary heart disease, acute pancreatitis, and cataracts

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

Nearly all of the energy needed by the body is provided by the ____________ of carbohydrates and lipids.

A

Oxidation

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

______________ is sourced from dietary fat, and synthesised in the liver cells.

A

Cholesterol

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

True or false: cholesterol is readily catabolised.

A

False

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

______________ cholesterol can be solubilised, and mixed micelles absorb in the intestine.

A

Unesterified

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

In intestinal mucosa, cholesterol is packaged with triglycerides, phospholipids, and specific apolipoproteins. The large, resulting lipoprotein is termed a ‘______________’.

A

Chylomicron

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

Cholesterol is important for cell membranes, steroid hormones, and ______ _______.

A

Bile acids

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

Where is cholesterol converted to bile acids?

A

Liver

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

List two places where cholesterol is required.

A

Adrenal glands and ovaries

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

Fatty acids are transported around the body by _______________.

A

Albumin

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

Fatty acids are simple chains of C-H bonds, terminating with a ___________ (COOH) group.

A

Carboxyl

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

Small amounts of the free form (unesterified) fatty acids are found in the __________, bound to albumin.

A

Plasma

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

Most fatty acids are found in ______________ or phospholipids.

A

Triglycerides

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

__________ fatty acids have no double bonds.

A

Saturated

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

Monounsaturated means ______ double bond.

A

One

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

_________________ means two or more double bonds.

A

Polyunsaturated

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

Unsaturated fatty acids are usually ______.

A

Fluid

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

_______ fatty acids are more similar to saturated fatty acids.

A

Trans

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

Triglycerides are also known as _______________.

A

Triacylglycerols

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

_________ fatty acid molecules are attached to one molecule of glycerol.

A

Three

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

True or false: plasma levels of triglycerides rise after a meal.

A

True

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

_________________ consist of two fatty acids.

A

Phospholipids

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

In phospholipids, the third position on the _________ ___________ contains the head.

A

Glycerol backbone

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

Phospholipids are described as being ‘amphipathic’. What does this mean?

A

They have both hydrophobic and hydrophilic regions

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

What is the principal storage unit of lipids?

A

Adipose tissue

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

Adipose tissue cells consist of fat ___________ of triglycerides.

A

Globules

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

Albumin carries free fatty acids, but how are other lipids transported?

A

In lipoprotein complexes

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

Describe the structure of lipoproteins.

A

Complex spherical structure, with hydrophobic core, wrapped in a hydrophilic coat. The core contains triglyceride and cholesteryl esters. Structures are classified according to density (as isolated by ultracentrifugation, inversely reflecting the size)

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

______________ are the largest lipoprotein, and they carry dietary triglycerides to the liver.

A

Chylomicrons

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

Very low-density lipoproteins (VLDL) carry triglycerides assembled in the _________ to cells for energy needs, or store them as fat.

A

Liver

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

Intermediate-density lipoprotein (IDL) is found in __________ amounts, except in pathological disturbances.

A

Small

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

_____ ___________ ___________ is almost empty of triglycerides, but rich in cholesterol. It delivers cholesterol to peripheral cells, and subtypes exist.

A

Low density lipoprotein

33
Q

High density lipoprotein gathers up extra _____________ for transport, taking it back to the liver (reverse cholesterol transportation).

A

Cholesterol

34
Q

_______________ are major component on surface of lipoproteins.

A

Apolipoproteins

35
Q

What naming convention do apolipoproteins follow?

A

Lettering from A to E

36
Q

List three functions of apolipoproteins.

A

Maintaining structural integrity
Regulating certain enzymes
Receptor recognition

37
Q

In _____________ metabolism, lipids are absorbed into the small intestine, then incorporated into a chylomicron.

A

Exogenous

38
Q

Describe endogenous metabolism of lipoproteins.

A

Chylomicron remnant is left, as triglycerides are lost. Liver synthesis of VLDL occurs. VLDL can be converted to IDL by lipoprotein lipase. IDL becomes LDL after further delopidation. HDL can be taken up either directly by the liver, or indirectly, for transfer to other lipoproteins, then return to the liver

39
Q

_____________ are synthesised by GIT after a meal.

A

Chylomicrons

40
Q

Chylomicrons are degraded by lipoprotein ____________ in the capillaries.

A

Lipases

41
Q

______ interacts with HDL to form mature VLDL, with added cholesterol and lipoproteins.

A

VLDL

42
Q

True or false: LDL is the principal carrier of cholesterol.

A

True

43
Q

LDL is removed from circulation by the high-affinity LDL ________.

A

Receptor

44
Q

_________ LDL levels promote atherosclerosis.

A

Elevated

45
Q

Small, dense, particles are considered the most _______________.

A

Proatherogenic

46
Q

What are lipoproteins (a)?

A

Another family of lipoproteins that consist of LDL and a protein called apo (a); association with coronary heart disease has been observed

47
Q

LDL receptors are _______________ present on the surfaces of all cells.

A

Glycoproteins

48
Q

LDL receptors are concentrated in special membrane recesses called _______ _____.

A

Coated pits

49
Q

LDL receptors bind ___ and E apoproteins on the surfaces of lipoproteins.

A

B

50
Q

Familial hypercholesterolaemia (FH) is an inherited malfunction, or absence, of ____________.

A

Receptors

51
Q

A mutation of apolipoprotein B results in defective binding of LDL, called ________ __________ _____ ___.

A

Familial defective Apo B

52
Q

HDL are the ___________ lipoproteins.

A

Smallest

53
Q

True or false: HDL contains cholesterol and phospholipids.

A

True

54
Q

HDL take cholesterol from extra-hepatic tissues, to the liver for _____________.

A

Excretion

55
Q

______ is anti-atherogenic.

A

HDL

56
Q

List two functions of HDL.

A

Transfer of proteins to other lipoproteins, and conversion of cholesterol to cholesteryl esters

57
Q

Lipid and lipoprotein results are significant for assessing __________ __________ _________ risk status.

A

Coronary heart disease

58
Q

What is the reference range for cholesterol?

A

3.0-5.0 mmol/L

59
Q

Cholesteryl ester ______________ cleaves fatty acid residue from cholesteryl esters.

A

Hydrolase

60
Q

Outline the enzymatic method of cholesterol quantification.

A

Cholesteryl ester hydrolase cleaves fatty acid residue from cholesteryl esters (which comprise about two-thirds). Enzyme catalyses the conversion of cholesteryl esters to free cholesterol. A second enzyme, cholesterol oxidase, catalyses the reaction of oxygen with cholesterol to produce hydrogen peroxidase. Hydrogen peroxidase is a common substrate for horseradish peroxidase. Peroxidase and dye combine to give a coloured complex

61
Q

What is the reference range for triglycerides?

A

0.4-2.0 mmol/L

62
Q

Triglycerides are required for the ____________ equation, which is used to calculate LDL cholesterol.

A

Friedewald

63
Q

Outline the principle of the enzymatic method of quantifying tryglycerides.

A

Glycerol and ATP with glycerol kinase react to generate glycerophosphate and ADP. Glycerophosphate and oxygen, in the presence of glycerophosphate oxidase react to generate dihydroxyacetone and hydrogen peroxidase. Peroxidase and dye combination follows

64
Q

True or false: endogenous free glycerol can interfere with methods used.

A

True

65
Q

HDL can be measured in _____________, following precipitation.

A

Supernatant

66
Q

_________ measurement, which uses modification of cholesterol esterase and oxidase, renders HDL-cholesterol more reactive that in other lipoproteins, and HDL-C is measured selectively.

A

Direct

67
Q

LDL cholesterol measurement methods assume that _________ ____________ is made up of VLDL-chol, LDL-chol, and HDL-chol.

A

Total cholesterol

68
Q

State the Friedewald equation.

A

(total cholesterol - HDL cholesterol - (triglyceride/2.2))

69
Q

LDL may be precipitated selectively with ____________ ___________/heparin (in low pH).

A

Polyvinyl sulphate

70
Q

List three methods that can be used to detect lipoproteins.

A

Ultracentrifugation, electrophoresis, and immunoassays

71
Q

________________ is caused by hardening of arteries due to deposition of atheromas.

A

Atherosclerosis

72
Q

List two conditions with which coronary heart disease is associated.

A

Angina and myocardial infarction

73
Q

Cardiovascular disease is especially associated with ________.

A

Stroke

74
Q

High levels of cholesterol may be caused by an unhealthy lifestyle, or by __________ ____________.

A

Genetic abnormalities

75
Q

________________ is most closely linked abnormality to heart disease.

A

Hypercholesterolaemia

76
Q

Hypertriglyceridaemia tends to be caused by genetic abnormalities, such as _________ ___________________.

A

Familial hypertriglyceridaemia

77
Q

Hypertriglyceridaemia can lead to _____________ (impaired catabolism of triglyceride-rich protein).

A

Nephrosis

78
Q

_______________ hyperlipidaemia involves elevated cholesterol and triglycerides.

A

Combined