KA7.3- Cholesterol

Question 1

(Production) 1) Cholesterol is synthesised… , …16

Answer 1

by all cells, although 25% of total production takes place in the liver

Question 2

(Production) 2) A diet high in … 17

Answer 2

saturated fats or cholesterol causes an increase in cholesterol levels in the blood

Question 3

(Production) 3) Drugs such as… by… 16

Answer 3

statins reduce blood cholesterol by inhibiting the synthesis of cholesterol by liver cells

Question 4

(Transport) a) HDL transports… 13 This prevents… 9 LDL transports… 6

Answer 4

excess cholesterol from the body cells to the liver for elimination
the accumulation of cholesterol in the blood
cholesterol to body cells

Question 5

(Transport) b) Most cells have… 15

Answer 5

LDL receptors that take LDL into the cells where it releases cholesterol

Question 6

(Transport) c) Once a cell has sufficient cholesterol… and LDL circulates… 33

Answer 6

a negative feedback system inhibits the synthesis of LDL receptors and LDL circulates in the blood where it may deposit LDL in the arteries forming atheromas

Question 7

(Transport) d) A higher ratio of HDL… 19

Answer 7

to LDL will result in lower blood cholesterol and a reduced chance of atherosclerosis

Question 8

(Transport) e) Regular… 8

Answer 8

physical activity tends to raise HDL levels

Question 9

(Role) i) Cholesterol is… 11

Answer 9

a type of lipid found in the cell membrane

Question 10

(Role) ii) It is also used to… - … , … , and …14

Answer 10

make the sex hormones - testosterone, oestrogen and progesterone