Metabolism

Question 1

CATABOLISM

Answer 1

Metabolic pathways that break down molecules into smaller units to release energy

Question 2

ANABOLISM

Answer 2

Metabolic pathways that construct molecules from smaller units. These require energy.

Question 3

State the major food groups and list the major sources and uses of each.

Answer 3

PROTEIN - Meat and pulses
CARBOHYDRATE - Pasta, bread and potatoes
FAT - Butter, vegetable oil
SUGAR - Sweets
MINERALS AND VITAMINS - Fruit and veg

Question 4

Distinguish between vitamins and minerals.

Answer 4

Vitamins act as co-enzymes and carry out many functions

Minerals are all different and have different purposes e.g calcium and phosphorus

Question 5

ENERGY BALANCE

Answer 5

The relationship between input of food and output of work. Positive when the body stores extra food as fat and negative when the body draws on stored fat to provide energy for work.

Question 6

Explain how each food group can be broken down to produce energy.

Answer 6

Carbohydrates are broken down into glucose
Proteins can be used to provide glucose if required. Produces ketones and acid as side products. Not very effective.
Fats quickly release energy but are not useful for endurance

Question 7

METABOLIC RATE

Answer 7

The rate of energy released from cells basal metabolic rate - the energy required to support the organs at rest.

Question 8

Describe the process of glycolysis and gluconeogenesis.

Answer 8

Gluconeogenesis - generation of glucose from a non-carbohydrate.

Respiration: Glycolysis takes place in cytoplasm and produces 2 pyruvate molecules, krebs cycle takes place on mitochondrial membrane and produces ATP, NADH and FAD. Oxidative phosphorylation (ETC) converts these products into ATP to end up with 38 ATP per glucose

Question 9

Explain the relationship between carbohydrates, fats and proteins as energy releasing substances.

Answer 9

Carbohydrates > Fats > Proteins

Question 10

Describe the roles of the regulatory hormones (insulin, glucagon, thyroxine and adrenaline) and identify their effects on peripheral metabolism.

Answer 10

Insulin decreases blood glucose levels by allowing cells to absorb it, increasing metabolism.
Glucagon raises blood glucose levels by converting the glycogen stores into glucose.
Thyroxine increases metabolism
Adrenaline increases metabolism to provide the body with enough energy to fight.