Catalytic RNA molecules are called

Appeared in: CIP Ranchi 2023

Explanation

Ribozymes are RNA (ribonucleic acid) molecules that possess catalytic activity, functioning as enzymes.
They are an exception to the general rule that all biological catalysts (enzymes) are proteins.
Key functions include roles in RNA splicing and protein synthesis within the ribosome.

Option A: This is the inactive protein component of an enzyme, which requires a non-protein cofactor to become active.
Option C: This is the complete, active form of an enzyme, consisting of the protein part (apoenzyme) combined with its necessary non-protein part (cofactor/coenzyme).
Option D: This is a non-protein, organic molecule that assists an enzyme in its catalytic function but is not itself the primary catalyst and is not made of RNA.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Biochemical Terminology: Enzymes and Catalytic Molecules as background academic context rather than a clinical decision trigger.
Understanding the different types of biological catalysts is fundamental to comprehending metabolic pathways and the mechanisms of drug action.
Some antibiotics target the bacterial ribosome's peptidyl transferase center, which is a ribozyme, to inhibit protein synthesis and kill the bacteria.
What if? If a patient has a genetic disorder affecting a specific enzyme's coenzyme binding site, they would have a functional apoenzyme but would be unable to form the active holoenzyme, leading to metabolic disease.

How to Approach the Question

First, identify the key terms in the question: 'Catalytic RNA molecules'.
The term 'catalytic' points towards an enzyme-like function.
The term 'RNA' is the crucial differentiator, as most enzymes are proteins.
Recall the definitions of the options. 'Apoenzyme', 'Holoenzyme', and 'Coenzyme' are all related to protein-based enzymes.
Recognize that 'Ribozyme' is a portmanteau of 'ribonucleic acid' and 'enzyme', directly matching the question's description.

Concept Tested & Keywords

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E6 textbook of Applied Biochemistry and Nutrition & DieteticsHarbans Lal (pp 26-464 of 479) p. 127-129

E6 Biochemistry U Satyanarayana— Part 1 (pp 26-420 of 840) pp. 91-93, 75-77

Practise the full CIP Ranchi 2023

Attempt every question from this paper in a timed mock, then review the full solution for each one.