Chapter 12

Question 1

What is the action of Oxidase?

Answer 1

• Oxidases catalyze the removal of hydrogen from a substrate using oxygen as a hydrogen acceptor
• They form water or hydrogen peroxide as a reaction product

Question 2

What is the action of a dehydrogenase class of enzyme?

Answer 2

1. Transfer of hydrogen from one substrate to another in a coupled oxidation-reduction reaction.
2. Transfer of electrons in the respiratory chain of electron transport from substrate to oxygen.

Question 3

What are the coenzymes that the dehydrogenase class of enzymes depend on?

Answer 3

Nicotinamide Coenzymes

• NAD⁺
• NADP⁺

Question 4

2 Types of Enzymes that Fall Under the Hydroperoxidase Category

Answer 4

• Peroxidases
• Catalase

Question 5

Peroxidases

Answer 5

Reduce peroxides using various electron acceptors

• H₂O₂ + AH₂ –Peroxidase–> 2 H₂O + A

Question 6

Catalase

Answer 6

Uses hydrogen peroxide as electron donor & electron acceptor

• 2H₂O₂ –Catalase–> 2 H₂O + O₂

Question 7

Oxygenases

Answer 7

Catalyze the direct transfer & incorporation of oxygen into a substrate molecule

Question 8

2 Types of Oxygenases

Answer 8

• Dioxygenases
• Monooxygenases

Question 9

Superoxide Dismutase

Answer 9

Protects aerobic organisms against oxygen toxicity