Brainscape's Knowledge GenomeTM

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


See full index

Biochemistry > Lipids > Flashcards

Lipids Flashcards

1
Q

What are triglycerides?

A

Glycerol carbon backbone with 3 fatty acids attached

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

Where are triglycerides synthesised?

A

Liver, adipose tissue and small intestine

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

What do phospholipids consist of?

A

Glycerol backbone with fatty acids plus a phosphate containing lipid

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

Lecithin and sphyngomyelin are examples of what?

A

Phosphate containing lipids

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

Phospholipids contain a polar and non polar group- what is this called?

A

Amphipathic molecules

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

Where are plasma phospholipids synthesised?

A

The liver

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

What makes up the hydrophobic tail of phospholipids?

A

Fatty acid

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

What is the stucture of cholesterol and what does it form part of?

A

Four ringed steroid nucleus- forms part of cell membranes

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

When is cholesterol found circulating in plasma?

A

When it is esterified to fatty acids

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

In the liver what is cholesterol synthesised from?

A

Acetate

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

What is the rate limiting enzyme in synthesis of chosterol?

A

B-hydroxyl b-methylglutaryl CoA reductase

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

How is cholesterol excreted?

A

It is metabolised to bile acids and excreted in bike

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

What are the 3 main functions of aplopoproteins?

A

1) the solubilise cholesterol esters and triglycerides
2) they regulate enzymes involved in lipid metabolism
3) bind to cell surface receptors

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

Why is ApoB100 and ApoB48 different?

A

In 48 a modification takes place in intestine cells - a stop is inserted into mRNA.
48 lacks LDL receptor

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

How many forms is there of ApoA and ApoC?

A

Two forms of ApoA 1 and 2

3 forms of C ApoC-I etc

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

What is the apopoliprotein and lipid associated with chylomicrons?

A

B48 and A, triglycerides

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

What is the apolipoprotein and lipid associated with VLDL

A

B100, C and E, triglycerides and cholesterol

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

What is the apolipoprotein and lipid associated with IDL

A

B100, C and E, triglycerides and cholesterol

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

What is the apolipoprotein and lipid associated with LDL?

A

B100, cholesterol

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

What does ApoC-II activate?

A

Lipoprotein lipase

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

What inhibits lipoprotein lipase?

A

ApoC-III

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

What is the apolipoprotein and lipid associated with HDL?

A

A,C,E cholesterol and phospholipids

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

What apolipoprotein is associated with receptor mediated transfer of cholesterol between tissues and plasma?

A

ApoE

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

What ApoE variant confers a risk for Alzheimer’s?

A

ApoE-4

25
Q

What did brown and Goldstein win the Nobel prize for?

A

Lipid transport

26
Q

As you progress from chylomicrons to HDL what happens protein, density and lipid?

A

Protein and density levels increase but lipid level decreases

27
Q

What makes up the non polar core of lipoproteins?

A

Cholesterol esters and triglycerides

28
Q

What makes up the polar surface of lipoproteins?

A

Phospholipids, free cholesterol and apolipoproteins

29
Q

What does the exogenous lipoprotein pathway do?

A

It deals with dietary lipids from the GI

30
Q

How are lipids absorbed from interstitial cells?

A

Synthesised into chylomicrons

31
Q

How do chylomicrons enter circulation?

A

Via the lymphatics and thoracic duct

32
Q

As chylomicrons travel through the blood what do they pick up?

A

They receive additional lipoproteins from HDL- including c and E

33
Q

Why is it important that chylomicrons pick up C and A?

A

As they enter adipose tissue the ApoC-II activates lipoprotein lipase in capillary endothelium, adipose tissue and muscle

34
Q

What is the effect of activated lipoprotein lipase?

A

It hydrolyses triglycerides to glycerol and fatty acids. Fatty acids can enter adipose tissue to be stored or muscle to be used up

35
Q

What happens chylomicrons once they are in the tissue?

A

They are depleted of triglycerides and enriched for cholesterol and taken up by liver receptors for apoB and E

36
Q

What does the endogenous lipoprotein pathway do?

A

Ensures there are enough lipids for peripheral tissue in between meals

37
Q

What is the start of the endogenous pathway?

A

VLDL is synthesised in the liver (containing cholesterol and triglycerides)

38
Q

Release of triglycerides from VLDL in tissue results in what?

A

Cholesterol rich particles - IDL

39
Q

What happens IDL?

A

It is processed to LDL in liver or in the circulation where it becomes LDL containing mostly cholesterol and apoB- t a sported to liver via LDL receptor

40
Q

What controls cellular cholesterol homeostasis?

A

LDL recognised by LDL receptor- internalised and degraded to release cholesterol

41
Q

What are you 3 mechanisms of cholesterol homeostasis?

A

1) down regulation of LDL receptor
2) stimulation of cholesterol esterification and storage
3) inhibition of hmg coA reductase

42
Q

How does the reverse cholesterol transport pathway start?

A

Starts at the liver that secretes nascent HDL. Cholesterol transferred to HDL in extrahepatic cells.

43
Q

In the reverse cholesterol transport pathway what does ApoA do?

A

It stimulate LCAT (lecithin-cholesterol acetyltransferase) which esterifies free cholesterol in HDL
Esterifies cholesterol is returned to liver for utilisation or excretion

44
Q

Why is HDL protective against CHD?

A

It removes excess cholesterol from peripheral tissues

45
Q

What gene is affected in familial hypercholesterolaemia

A

LDL receptor

46
Q

What is another inherited disease of lipid metabolism

A

Familial defective apolipoprotein B100

47
Q

What is the inheritance pattern of FH?

A

AD

48
Q

What is the result of FH?

A

Reduced clearance of cholesterol rich LDL particles - high plasma total cholesterol and LDL cholesterol

49
Q

What happens in secondary hypercholesterolaemia?

A

Elevated cholesterol and/or triglycerides - seen in alcohol a purse, hypothyroidism, diuretics, oestrogens

50
Q

What do statins do?

A

Inhibit cholesterol synthesis

51
Q

What does cholestyramine do?

A

Inhibits cholesterol and bile salts absorption

52
Q

What do fibrates do?

A

Reduced cholesterol and triglycerides

53
Q

What is the Friedewald equation?

A

Used to calculate LDL cholesterol

LDL cholesterol =total chol- HDL chol- TG/ 2.2 (if results in mol/L) or 5 (if results in mg/dl)

54
Q

What is the fault with Friedewald equation?

A

It assumes all plasma TG is carried on VLDL and it estimates the ratio of triglycerides to VLDL

55
Q

What is a normal total cholesterol level?

A
56
Q

What is normal LDL cholesterol?

A
57
Q

What is normal HDL?

A

1mmol/L or more

58
Q

What should normal triglycerides be?

A

1.7mmol/L or less

Biochemistry (8 decks)

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