Liver Function

Question 1

What metabolic functions does the liver carry out?

Answer 1

• Control of blood glucose levels, amino acid levels, lipid levels
• Synthesis of bile, plasma proteins, cholesterol
• Synthesis of red blood cells in fetus
• Storage of vitamins A,D and B12, iron, glycogen
• Detoxification of alcohol, drugs
• Breakdown of hormones
• Destruction of red blood cells

Question 2

Why are fetal red blood cells made in the fetus liver and not in the bones?

Answer 2

Because the fetus does not have enough density in its bones

Question 3

Hepatocyte

Answer 3

Liver cell

Question 4

Glycogenesis

Answer 4

Making glycogen from glucose

Question 5

Glycogenolysis

Answer 5

Breaking down glycogen to glucose

Question 6

Gluconeogenesis

Answer 6

Glucose newly made from amino acids

Question 7

Glycolysis

Answer 7

Breaking down glucose to form pycurate

Question 8

How does the liver store sugars?

Answer 8

In the form of glycogen

Question 9

Approx. how much glycogen can the liver store?

Answer 9

100-120g -8% of the fresh weight of liver

Question 10

Where does glycogen form granules?

Answer 10

In the cytoplasm of hepatocytes

Question 11

What chemicals produced in the body may be toxic?

Answer 11

• Hydrogen peroxide

- Ammonia

Question 12

How can toxins be rendered harmless?

Answer 12

• Oxidation
• Reduction
• Methylation
• Combination with another molecule

Question 13

What enzymes in the liver cells render toxic molecules less toxic?

Answer 13

• Catalase

- Cytochrome P450

Question 14

Catalyse

Answer 14

• Enzyme which coverts hydrogen peroxide to oxygen and water
• Has a particularly high turnover number of 5 million

Question 15

Turnover number

Answer 15

The number of molecules of hydrogen peroxide that one molecule of catalyse can render harmless in one second

Question 16

Cytochrome P450

Answer 16

• A group of enzymes used to breakdown drugs e.g. Cocaine and various medicinal drugs
• The cytochromes are used in metabolic reactions

Question 17

What metabolic reactions are the cytochromes in cytochrome P450 involved in?

Answer 17

Electron transport during photosynthesis

Question 18

What do p450 enzymes show between individuals?

Answer 18

A lot of variation

Question 19

How is alcohol broken down?

Answer 19

• in the Hepatocytes by the action of the enzyme dehydrogenase
• This is dehydrogenated further by the enzyme ethanal dehydrogenase
• Final product produced is ethanoate (acetate)
• Acetate is combined with coenzyme A to form acetyl coenzyme A, which enters the process of aerobic respiration