Question

multiple choice question

composed principally of amino acids, and acting as biological catalysts, ______ facilitate metabolic activities of the cell.

cofactors
enzymes
ribozymes
ribosomes

Explanation:

Analyze the key terms in the question stem

The question describes substances that are:

1. "Composed principally of amino acids" (meaning they are proteins).
2. "Acting as biological catalysts" (substances that speed up chemical reactions without being consumed).
3. Functioning to "facilitate metabolic activities of the cell."

Evaluate the given options

• cofactors: Non-protein chemical compounds or metallic ions required for an enzyme's activity.
• enzymes: Macromolecular biological catalysts composed principally of amino acids (proteins) that accelerate metabolic chemical reactions.
• ribozymes: RNA molecules that have catalytic activity (composed of nucleotides, not amino acids).
• ribosomes: Cellular structures made of RNA and proteins that perform protein synthesis, not the primary individual metabolic catalysts themselves.

Determine the correct choice

Based on the definition of being made of amino acids and acting as biological catalysts to facilitate cellular metabolism, the correct term is enzymes.

Answer:

• cofactors
• enzymes (Correct answer)
• ribozymes
• ribosomes