Question

Which sentence characterizes enzymes in the human body? A. Most are made of starch. B. Most catalyze only one type of reaction. C. Most require an acid to work. D. Most are lipids.

Answer 1

The correct answer should be the option b - Most catalyze only 1 type of reaction.

Enzymes are proteins that are made up of a string of amino acids. They act as biological catalysts that help in carrying out the reactions needed for the metabolic functioning of the body. Enzymes collaborate with other non-proteins called coenzymes to carry forward a reaction.

One type of an enzyme interacts chemically with only 1 particular type of substance which is called as a substrate. Each enzyme reacts only with one particular substrate in such a way that they form a perfect fit for each other. This theory is called the 'Lock and key' theory, postulated by Emil Fischer.

Answer 2

The correct answer is - b. Most catalyze only one type of reaction.

The fundamental characteristics of enzymes are:

i. They speed up a reaction.

ii. They are not permanently altered by a reaction. So an enzyme molecule can be used again and again to catalyze the same reaction.

iii. They can catalyze both the forward and the reverse reaction.

iv. They are highly specific for the substrates they bind that means they catalyze only one reaction.