I understand the role of enzymes in chemical reactions but metabolism is the sum of all the reactions in a cell or in the body. So how do enzymes control metabolism? Can they change the number of reactions in a body or can enzymes just control the chemical reactions in the body?

If the definition of metabolism was chemical reactions that occur in the body, then I would understand how enzymes control metabolism, but the word 'sum' is confusing to me. I would really appreciate if somebody can explain this to me.

Thanks for reading.

4 answers

Also, if they can change the number of reactions in a body, how?
Since Jiskha doesn't have a biology expert at this time, please try posting your question at this site.

http://www.biology-online.org/biology-forum/

In addition, be sure to make really good use of Khan Academy!
https://www.khanacademy.org/science/biology
Click on the Subjects link at the top, and then find the specifics you need within each topic.
Doubt it if someone will respond with a lengthy answer, which would be required to answer such a question of questions. Try Nature's website with regards to tutorials concerning enzymes and proteins. You don't need someone to summarize the information that is readily available to you.
writeteacher, thanks