4.4.2.3 Metabolism

Question 1

Metabolism:

Answer 1

the sum of all the reactions in a cell or the body

Question 2

What is the energy transferred in respiration in cells used for?

Answer 2

the energy transferred in respiration is used by the organism for the continual enzyme controlled processes of metabolism that synthesise new molecules

Question 3

What is important in the synthesis and break-down of carbohydrates, proteins and lipids?

Answer 3

sugars, amino acids and glycerol

Question 4

What does metabolism include?

Answer 4

• conversion of glucose to starch, glycogen and cellulose
• the formation of lipid molecules from a molecule of glycerol and three molecules of fatty acids
• the use of glucose and nitrate ions to form amino acids which in turn are used to synthesis proteins
• respiration
• breakdown of excess proteins to form urea for excretion

Question 5

What sort of a molecule is glycogen?

Answer 5

Carbohydrate used as an energy store

Question 6

What is glycogen made of?

Answer 6

Glucose molecules joined in chains

Question 7

Where is glycogen found?

Answer 7

In animals, in liver (mainly) and muscles

Question 8

When is glycogen made?

Answer 8

When blood glucose levels are high (after meals and when resting)

Question 9

Which hormone promotes glycogen formation?

Answer 9

Insulin

Question 10

When is glycogen used?

Answer 10

When blood glucose levels are low (when fasting and exercising)

Question 11

How is glycogen used?

Answer 11

Broken down into glucose molecules which are then respired