Chemical Forums

Specialty Chemistry Forums => Biochemistry and Chemical Biology Forum => Topic started by: jena on October 18, 2005, 06:08:19 PM

Title: Nature of the Enzyme?
Post by: jena on October 18, 2005, 06:08:19 PM

Hi,

My Question:

What is the nature of the enzyme that catalyzes the following reactions?

a. ATP + Glucose --> ADP + Glucose
Answer: hydrolase

b. CH₃-CH₂-OH---->CH₃-CHO has NAD⁺ ----. NADH+ H ⁺ as the enyme usedAnswer: oxyreductase

Are these the correct answers?

Thank You :)

Title: Re:Nature of the Enzyme?
Post by: Yggdrasil on October 18, 2005, 07:27:10 PM

a.  Are you sure you copied the reaction correctly?  I would double check it.

b.  Correct, although it should be spelled oxidoreductase.

Title: Re:Nature of the Enzyme?
Post by: jena on October 18, 2005, 09:02:39 PM

Sorry :-[ your right  part a is supposed to be

ATP + Glucose --> ADP + Glucose-6-P

Is this correct ???

Thanks

Title: Re:Nature of the Enzyme?
Post by: Yggdrasil on October 19, 2005, 12:18:49 AM

That is not a hydrolase reaction.  A phosphate group from ATP is being transfered to glucose, hence the enzyme is a transferase.  In fact, enzymes which transfer phosphates to and from ADP/ATP are of a special subclass called kinases, which play very important roles within metabolism and signaling.  Although the phosphoester bond of ATP is hydrolyzed in the reaction, its hydrolysis is coupled to the formation of a phosphoester bond with glucose, so it is a transferase and not a hydrolase (usually a hydrolase will have one reactant and two products).