Metabolism and Nutrition

Question 1

Oxidation of 1g of Glucose gives how many kcal?

Answer 1

4 kcal

Question 2

Oxidation of 1g of Fat gives how many kcal?

Answer 2

9 kcal

Question 3

What are the main four macronutrients?

Answer 3

Carbohydrates
Fat
Protein
Dietary Fibre

Question 4

Oxidation of 1g of Protein gives how many kcal?

Answer 4

4 kcal

Question 5

Oxidation of 1g of Alcohol gives how many kcal?

Answer 5

7 kcal

Question 6

Can the body store fats, glycogen, alcohol and protein?

Answer 6

Fats = Yes, infinitely
Glycogen = Yes, finitely (100g liver, 350g muscle)
Protein = No
Alcohol = No

Question 7

What is the maximum yield of ATP per glucose molecule? What is the more realistic value however?

Answer 7

36. and 32

Question 8

During glycolysis of 1 glucose molecule, the net yield of ATP and NADH is..?

Answer 8

2 ATPs

2 NADH

Question 9

What are the ten sub-products of glycolysis?

Answer 9

1. Glucose
2. Glucose-6-Phosphate
3. Fructose-6-Phosphate
4. Fructose-1,6-Bisphosphate
5. Glyceraldehyde-3-Phosphate + Dihydroxyacetonephophate
6. Bisphosphoglycerate
7. 3-Phosphoglycerate
8. 2-Phosphoglycerate
9. Phosphoenolpyruvate
10. Pyruvate

Question 10

Where does glycolysis occur?

Answer 10

Cell cytoplasm

Question 11

Where does the TCA cycle occur?

Answer 11

Mitochondrial matrix

Question 12

Where does Oxidative Phosphorylation occur?

Answer 12

Mitochondrial membrane

Question 13

During anaerobic glycolysis, pyruvate is converted into..?

Answer 13

Lactate

Question 14

What happens in the Cori cycle?

Answer 14

Lactate produced by anaerobic glycolysis in the muscles moves to the liver and is converted to glucose, which then returns to the muscles and is metabolized back to lactate

Question 15

What is beta oxidation?

Answer 15

Fatty acid molecules are broken down in the mitochondria to generate Acetyl CoA and enters the TCA cycle

Question 16

Can fatty acids be converted directly into glucose / glycogen?

Answer 16

NO

Question 17

Why does the Pentose Phosphate Pathway exist?

Answer 17

Provision of Pentose for DNA/RNA synthesis

Provides NADPH for fat synthesis

Question 18

Why does ketogenesis occur?

Answer 18

1. High rate of fatty acid oxidation in the liver

2. When carbohydrate metabolism is impaired

Question 19

Some amino acids can be converted to glucose and some cannot. Which class of AAs can and which can’t?

Answer 19

Glucogenic AAs = yes

Ketogenic AAs = no

Question 20

In plasma, the glucose levels for the starvation state is…?

Answer 20

3.5 mmol / L