Which of the following statements is correct with reference to enzymes?
- Holoenzyme = Apoenzyme + Coenzyme
- Coenzyme = Apoenzyme + Holoenzyme
- Holoenzyme = Coenzyme + Co-factor
- Apoenzyme = Holoenzyme + Coenzyme
Answer
(1) Holoenzyme = Apoenzyme + Coenzyme
Solution
As per NCERT, the protein portion of an enzyme is called the apoenzyme, and the non-protein constituent bound to it is the co-factor (e.g. a coenzyme).
⇒ When the co-factor is removed from the enzyme, catalytic activity is lost.
⇒ The complete, catalytically active enzyme (holoenzyme) = apoenzyme + co-factor (coenzyme).
∴ Holoenzyme = Apoenzyme + Coenzyme.
Answer: (1)