Question

The substance responsible for accelerating chemical reactions in biological systems is:

• A. Bacteria
• B. DNA
• C. Enzyme
• D. Protein

Hint:

The answer is the specific type of protein that acts as a biological catalyst.

Answer 1

The Correct Option is C

Step 1: Understand what the question is asking.
The question wants the name of the substance that speeds up chemical reactions taking place inside living cells.

Step 2: Recall the role of enzymes.
A biological catalyst that lowers the activation energy of a reaction, and so speeds it up without being used up itself, is called an enzyme. Enzymes act on specific substrates and are needed for digestion, respiration, and almost every other reaction that happens in the body.

Step 3: Rule out the other options.
Bacteria are living organisms, not a substance that speeds up a reaction, though some bacteria do produce enzymes. DNA stores genetic information and does not itself catalyse chemical reactions. Protein is the broad chemical class that enzymes belong to, but the word protein also covers structural and transport proteins that do not catalyse reactions, so it is too general to be the exact answer here.

Step 4: Final answer.
The specific substance named for speeding up biological reactions is the enzyme.
\[ \boxed{\text{Enzyme}} \]