Lipid metabolism Flashcards

1
Q

Where are chylomicrons formed?

A

small intestine

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

What are Lipo proteins made up of?

A

Composed of triglyceride, cholesterol ester (in inner core) + cholesterol, phospholipids, apolipoproteins (eg. apo-AI, -B48, -CI, -D, -E) in outer layer

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

_____ density lipoprotein (VLDL)

_____ density lipoprotein (IDL) / VLDL remnants

A

Very low (VLDL)

Intermediate (IDL)

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

____density lipoprotein (LDL)

____density lipoprotein (HDL)

A

Low (LDL)

High (HDL)

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

Most lipids are transported in the blood in combination with proteins as______

(Note non polar lipids in centre)

A

Lipoproteins

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

Which organ removes Chylomicron remnants?

A

liver

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

ROLES OF CHOLESTEROL?

A

Synthesis of membranes (stabilizes membranes especially plasma membrane)

Synthesis of bile acids (needed for digestion)

Synthesis of steroid hormones (e.g. androgens)

Synthesis of Vitamin D in skin from 7-dehydrocholesterol & UVB light.

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

Where do Excess LDL particles accumulate?

A

Excess LDL particles accumulate in artery wall and are chemically altered

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

What are the chylomicrons triglyceride fatty acids used for?

A

Used by muscle cells for ATP production

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

What type of type of triglycerides do VLDLs contain?

A

endogenous triglycerides.

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

What are VLDLs role?

A

They are transport vehicles that carry triglycerides synthesized in hepatocytes to adipocytes for storage.

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

What percentage of total blood cholesterol do LDLs deliver to cells throughout the body?

A

75%

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

Where do LDLs deposit cholesterol when present in excessive numbers?

A

smooth muscle fibers in arteries

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

What are HDLs role?

A

HDLs remove excess cholesterol from body cells and transport it to the liver for elimination (reverse cholesterol transport).

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

APOLIPOPROTEINS TYPES:

A

Apo A-I, Apo A-II, Apo A-IV

Apo B-48, Apo B-100

Apo C-I, Apo C-II, Apo C-III

Apo D

Apo E

Apo(a)

(Note Apo B is an integral apolipoprotein whereas the others are peripheral apolipoproteins)

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

ROLE OF APOLIPOPROTEINS:

A

Solubilizes highly hydrophobic lipids (Apo B)

Contains signals (ligands) to regulate movement

Enzyme Cofactors e.g. Apo A-I for lecithin cholesterol acyl transferase (LCAT), Apo C-II for lipoprotein lipase, Apo A-II activates hepatic lipase

Enzyme inhibitors e.g. Apo A-II & Apo C-III for lipoprotein lipase, Apo C-I for cholesteryl ester transfer protein

Lipid Transfer Protein

17
Q

ROLES OF CHOLESTEROL

A

Synthesis of membranes (stabilizes membranes especially plasma membrane)

Synthesis of bile acids (needed for digestion)

Synthesis of steroid hormones (e.g. androgens, oestrogens, progesterone, glucocorticoids & mineralocorticoids)

Synthesis of Vitamin D in skin from
7-dehydrocholesterol & UVB light.

18
Q

What are the four classes of lipoproteins?

A

Chylomicrons
VLDLs
LDLs
HDLs

19
Q

How are VLDLs converted to LDLs?

20
Q

What is the order of lipoproteins with relation to increasing density? Starting with least dense.

A

chylomicron, VLDL, IDL, LDL, HDL

21
Q

What is the order of lipoproteins with relation to increasing diameter? Starting with smallest diameter

A

HDL, LDL, IDL, VLDL, chylomicron

22
Q

What is the order of lipoproteins with relation to increasing protein content ? starting with the smallest protein content.

A

chylomicron, VLDL, IDL, LDL, HDL

23
Q

What is the order of lipoproteins with relation to increasing TG content ? Starting with the smallest TG content.

A

HDL, LDL, IDL, VLDL, chylomicron

24
Q

How is Atherosclerotic Plaque Formed?

A

Excess LDL particles accumulate in artery wall and are chemically altered

25
What does Modified LDL attract and stimulate?
Modified LDL stimulate endothelial cells to attract monocytes & T cells to intima
26
Monocytes become macrophages. T cells and macrophages secrete ______
cytokines
27
Macrophages feast on LDLs and become_______ and with T cells form fatty streak
Foam cells
28
What does Plaque develop into?
Plaque grows as fatty streak develops into atheroma with a fibrous cap and can restrict blood flow
29
Usually ______ weakens and plaque ruptures and clot forms and may cause eg. unstable angina and myocardial infarction
Cap
30
What are the two major sources of cholesterol in the body?
dietary ingestion (exogenous) and hepatic synthesis (endogenous).