SS2. Cardio vascular system - Cholesterol metabolism, LDL, HDL, other Lipoproteins

Question 1

Why is cholesterol important?

Answer 1

For cell membrane, it’s a precursor for bile, steroid hormones and vit. D.

Question 2

How does cholesterol travel?

Answer 2

It travels in lipoprotein

Question 3

What density and size does a chylomicron have?

Answer 3

Lowest density of cholesterol/triacylglyceride, largest in size.

Question 4

What density and size does a VLDL have?

Answer 4

low density of cholesterol/triacylglyceride, 2nd in size but still large

Question 5

What density and size does an LDL have?

Answer 5

Low density of cholesterol/triacylglyceride inside, 2nd smallest in size

Question 6

What density and size does an HDL have?

Answer 6

High density of lipoproteins (cholesterol, triacylglycerides e.g.)

Question 7

Where does LDL carry cholesterol to?

Answer 7

From liver to tissues, considered bad cholesterol

Question 8

Where does HDL carry cholesterol to?

Answer 8

returns excess cholesterol to the liver

Question 9

Explain the route dietary cholesterol takes, with all the density lipoproteins

Answer 9

1) Dietary cholesterol is packaged into a chylomicron, carried through the blood to the liver.
2) Liver packages it + triacylglycerides into VLDL. 3) VLDL travels into bloodstream to organs. Muscle/adipose tissues extract triacylglycerides from VLDL, turning into LDL.

Question 10

How do peripheral cells take up LDL?

Answer 10

Via endocytosis.