4.a.b. Metabolism and the nature of enzymes

Question 1

‘Reactions occur in metabolic lines’ True or False?

Answer 1

FALSE; metabolic pathways

Question 2

What are the two types of metabolic pathways and what do they do?

Answer 2

• Anabolic, builds molecules up

- Catabolic, breaks molecules down

Question 3

Give an example of an anabolic and a catabolic reaction

Answer 3

• Anabolic= protein synthesis

- Catabolic=digestion

Question 4

What are metabolic pathways controlled by?

Answer 4

Enzymes

Question 5

What happens to the products of an enzyme-controlled reaction?

Answer 5

They become reactants of the next reaction

Question 6

Why are enzymes also known as ‘biological’ catalysts?

Answer 6

Because they are made by living cells

Question 7

Give four universal properties of enzymes

Answer 7

• Speed up reactions
• Not used up
• Not changed
• Have a high turn-over rate

Question 8

Enzymes only catalyse certain reactions, reactions which… (2)

Answer 8

…are energetically favourable and ones that would happen anyway

Question 9

What are the 6 structural properties of enzymes?

Answer 9

• Tertiary structure
• Globular/spherical
• Hydrophilic R groups on the outside
• Soluble
• Has an active site
• Has bonds

Question 10

How are the bonds that amino acids make with each other determined?

Answer 10

• Each element has a particular sequence of amino acids

- Elements in the R groups determine the bonds that the amino acids make with each other

Question 11

What are the three types of bond that an amino acid can make?

Answer 11

• Hydrogen
• Disulphide
• Ionic