lipids in health and disease

Question 1

what are blood fats

Answer 1

lipids, cholesterol, triglyceride

Question 2

how does cholesterol help the plasma membrane

Answer 2

helps maintain structure and fluidity. forms good seal between inside and outside cell

Question 3

what role does cholesterol play in signalling

Answer 3

cholesterol helps form lipid ‘rafts’ that form bridges between receptor proteins and second messengers. rafts serve as centres for assembly of signalling molecules

Question 4

cholesterol as precursor molecules

Answer 4

for bile/bile acids, vitamin D and steroid hormones

Question 5

triglycerides function in health

Answer 5

similar role to cholesterol in cell membranes. highly concentrated energy stores

Question 6

what proteins carry lipids round the body

Answer 6

lipo protein molecule

Question 7

what do lipo protein molecules require to work

Answer 7

they require specialised proteins to carry them around in aqueous blood

Question 8

ideal measurement of total cholesterol

Answer 8

<5 mmol/L

Question 9

kinds of cholesterol transport

Answer 9

2 types. liver to tissue. tissue to liver

Question 10

what is liver to tissue cholesterol transport mediated by

Answer 10

relatively buoyant lipoproteins like VLDL which after delipidation become IDL

Question 11

what is tissue to liver transport also called

Answer 11

reverse cholesterol transport and its mediated by HDL

Question 12

whys it important to keep liver to tissue and tissue to liver transport in balance

Answer 12

particularly if reverse cholesterol transport cannot match transport to the tissues, then cholesterol (especially LDL cholesterol) accumulates, contributing to atherosclerosis.

Question 13

atherosclerosis

Answer 13

basically inflammation on inner walls if arteries. earliest change takes place in endothelium of arteries.

Question 14

what changes take place in the endothelium of arteries in atherosclerosis

Answer 14

They include increased endothelial permeability to lipoproteins and other plasma constituents; up-regulation of leucocyte (white blood cell) and endothelial adhesion molecules; and migration of leucocytes into the artery wall. This last is mediated by various things notably including oxidised low-density lipoprotein (LDL).

Question 15

what happens once endothelium is disturbed

Answer 15

white cells continue to get into lining, and smooth muscle moves in response. more and more cells develop on top in response, developing plaque underneath. after time cells build up and artery is blocked. scar tissue tries to make a cap on the plaque. but eventually is can rupture which can lead to clotting and maybe haemorrhage