Name:

Candidate number:

Theme: Lipoprotein metabolism

OPTION LIST

A	HDL	I	Serum chylomicron remnants
B	Hydrolysed LDL	J	Serum chylomicrons
C	IDL	K	VLDL
D	HDL remnants	L	Non-oxidised LDL
E	Internalised VLDL
F	Lymphatic chylomicrons
G	Oxidised LDL
H	Receptor-bound chylomicron remnants

For each scenario below, choose the most appropriate answer from the list above. Each option may be used once, more than once or not at all.

1. Lipoproteins that originate in capillaries and are carried to the liver

2.Lipoproteins that originate from liver and intestine and are 30 nm in diameter

3.Contain APO B-100 and E but not APO C or B-48

4.Contain trigyceride from meals and are ready to enter the circulation

5.Formed from the action of lipoprotein lipase on VLDL

ANSWERS

1. I

Serum chylomicron remnants. These originate in capillaries when chylomicrons are depleted of their triglyceride. These are carried to the liver then bind receptors where they are internalised immediately.

2. K

VLDL. Both VLDL and HDL originate in liver and intestine but HDL is 7.5-10 nm whereas VLDL is 30-80nm. NB density is inversely proportional to lipid content.

3. C

IDL. VLDL also contains B-100 and E but also has APO C

4. F

Lymphatic chylomicrons. Chylomicrons are formed in the intestinal mucosa then enter the circulation via the lymphatics

IDL. Once VLDL transport triglycerides to extrahepatic tissues and the triglyceride is largely removed by lipoprotein lipase, they become IDL