Question

Which of the following is true for enzymes?

I. They are proteins.
II. Typically work best at pH 7.2.
III. They are changed during a reaction.
IV. They are formed in the nucleus only.

• A. I only
• B. II only
• C. I and II only
• D. I,II and III only
• E. I, II,III and IV

Answer 1

The correct option is C I and II only

Enzymes are macromolecular biological catalysts. They accelerate, or catalyze, chemical reactions.The molecules at the beginning of the process are called substrates and the enzyme converts these into different molecules, called products.

The characteristics of Enzymes:

They are proteins in nature and like all proteins, enzymes are linear chains of amino acids that fold to produce a three-dimensional structure.

Enzymes are affected by changes in pH. The most favorable pH value - the point where the enzyme is most active - is known as the optimum pH. The optimum pH value will vary greatly from one enzyme to another, however they work best at neutral pH around 7.2.

They does not change during a reaction and only accelerates the reaction.

They are generally formed via ribosomes and Endoplasmic reticulum. Therefore only 1st and 2nd statements are correct.
So, the correct answer is option A.