Liver Biochemistry

Question 1

What are the 5 main functions of plasma proteins?

Answer 1

1. Maintenance of oncotic or colloid osmotic pressure.
2. Transport of hydrophobic substances.
3. pH buffering.
4. Enzymatic.
5. Immunity.

Question 2

What are the functions of alpha-globulins produced by the liver?

Answer 2

Transport lipoproteins, lipids, hormones and bilirubin.

Question 3

Give 2 examples of alpha-globulins.

Answer 3

Caeruloplasmin, retinol binding protein (transports vitamin A).

Question 4

Give 2 examples of beta-globulins produced by the liver.

Answer 4

Transferrin, fibrinogen.

Question 5

Why does albumin have a high capacity for hydrophobic substances even though it has a low affinity?

Answer 5

There is a high concentration.

Question 6

What 3 endogenous substances does albumin transport?

Answer 6

Fatty acids, bilirubin, thyroid hormones.

Question 7

What exogenous substance does albumin transport?

Answer 7

Aspirin.

Question 8

In what form is Iron transported?

Answer 8

Ferric iron Fe3+.

Question 9

What are thyroxine and cortisol transported in the blood bound to?

Answer 9

Thyroxine - thyroid-binding globulin.

Cortisol - cortisol-binding protein.

Question 10

What does hormone binding to transport proteins allow?

Answer 10

Extended biological half-life and increased plasma concentration.

Question 11

What reaction does HMG-CoA reductase catalyse?

Answer 11

Irreversible formation of mevalonic acid.

Question 12

What is vitamin D produced from?

Answer 12

Cholesterol.

Question 13

What are the 3 groups of steroid hormones?

Answer 13

Corticosteroids, androgens, oestrogens.