Biochemistry

Question 1

What is cellular respiration?

Answer 1

• Transfer of electrons from C to O

Question 2

Which macronutrient is the most dense form of carbon energy store?

Answer 2

Fat

Question 3

3 AA essential for premature babies

Answer 3

• Cysteine
• Glycine
• Arginine

Question 4

3 qualities to define a vitamin

Answer 4

• Essential organic compounds
• Needed in small quantities
• Not synthesised in the body

Question 5

What is a vitamer?

Answer 5

• Chemical variants that make up a vitamin

Question 6

Thiamine function

Answer 6

• Enzyme co-factor = thiamine pyrophosphate
• Contributes to many aspects of respiration and metabolism
• Need for the catabolism of many macronutrients

Question 7

Movement of thiamine

Answer 7

• Absorbed readily

- Not stored

Question 8

Disorder related to thiamine

Answer 8

Beriberi

• Peripheral nerve impairment
• Deficient GABA and glutamate production

Question 9

Pyridoxine function

Answer 9

• Enzyme co-factor = pyrydoxial-5-phosphate
• More than 140 dependent activities
• Crucial for AA metabolism

Question 10

Pyridoxine movement

Answer 10

• Readily absorbed by diffusion

- Negative charge maintains it in the cell

Question 11

Riboflavin function

Answer 11

• Enzyme co-factor = enzyme transfer reactions

- Catalyses difficult redox reactions

Question 12

Riboflavin movement

Answer 12

• Absorbed in the small intestines as riboflavin

- Passive and active absorption - channels and transporters

Question 13

Nicotinic acid/niacin/nicontinamide function

Answer 13

• Electron carrier in the form NADH and NADPH

Question 14

Nicotinic acid/niacin/nicontinamide movement

Answer 14

• Well-absorbed in the small intestine
• Transported in solution in plasma
• Can be made from tryptophan

Question 15

Nicotinic acid/niacin/nicontinamide disorder

Answer 15

PELLEGRA

• Deficiency
• Inflamed skin, diarrhoea, dementia, sores in mouth

Question 16

Folate function

Answer 16

• Mediates much of 1 carbon metabolim as THF
• Purine and pyrimidine biosynthesis (for DNA and RNA)
• Some AA metabolism

Question 17

Folate movement

Answer 17

• Active and facilitated uptake
• Passive = reduced folate carrier
• Active = protein-coupled folate transporter

Question 18

Folate deficiency

Answer 18

Affects rapidly dividing cells

• Megablastic anaemia
• Neural tube defects

Question 19

Cobalamin function

Answer 19

• Specific methyltransferase reactions
• Breakdown of odd-length fatty acids
• Methionine synthesis

Question 20

Cobalamin movement

Answer 20

• Transport requires proteins at each step
• Carrier proteins
• IF
• Transcoballaine
• Can be stored in the liver for 5 years

Question 21

Cobalamin disorders

Answer 21

Pernicious anaemia

• Lack of intrinsic protein leads to cobalamin deficiency
• Causes a depletion of folic acid - accumulates as THF

Question 22

Biotin function

Answer 22

• Co-factor for caboxylase enzymes

Question 23

Biotin movement

Answer 23

• Covalently attached to enzymes

- Readily absorbed by the intestines

Question 24

Pantothenic acid function

Answer 24

• Precursor for coenzyme-A

Question 25

Pantothenic acid movement

Answer 25

• Active Na dependent transport

Question 26

PDHc links what 2 processes?

Answer 26

• Glycolysis

- TCA cycle