During the process of cell translation, which strand moves along the ribosome and creates a new protein?

Appeared in: UP NHM CHO 7 Sept 2022(shift-1st)

Explanation

Messenger RNA (mRNA) is transcribed from a DNA template in the nucleus and carries the genetic instructions to the cytoplasm.
It functions as the template strand that moves through the ribosome during translation.
The sequence of codons on the mRNA molecule dictates the specific sequence of amino acids in the protein being synthesized.

Option A: Ribosomal RNA (rRNA) is a structural and catalytic component of the ribosome itself. It forms the 'workbench' for protein synthesis but is not the template that is read.
Option B: Double-stranded RNA (dsRNA) is not used as a template for protein translation in human cells. Its presence is often associated with viral infections or gene regulation mechanisms like RNA interference.
Option D: Transfer RNA (tRNA) acts as an 'adapter' molecule. It carries specific amino acids to the ribosome and matches its anticodon to the mRNA's codon, but it does not serve as the primary blueprint for the entire protein.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Roles of different RNA types in protein synthesis (translation) as background academic context rather than a clinical decision trigger.
Understanding protein synthesis is fundamental to pharmacology, as many antibiotics (e.g., macrolides, tetracyclines, aminoglycosides) work by specifically targeting and inhibiting bacterial ribosomes, thereby stopping bacterial growth without harming human cells.
This concept is also key to understanding genetic diseases. A mutation in a gene can lead to an altered mRNA sequence, which in turn can produce a faulty or non-functional protein, causing conditions like sickle cell anemia or cystic fibrosis.
What if? If a mutation creates a premature 'stop' codon on the mRNA, translation will halt early, resulting in a truncated and usually non-functional protein. This is a common mechanism in many genetic disorders.

How to Approach the Question

First, identify the core biological process described in the question: 'cell translation,' which is the synthesis of a 'new protein' on a 'ribosome'.
Next, focus on the specific action mentioned: a 'strand' that 'moves along the ribosome' to direct this process.
Recall the distinct functions of the major RNA types involved in translation.
rRNA (ribosomal): Forms the structure of the ribosome.
tRNA (transfer): Transports amino acids to the ribosome.
mRNA (messenger): Carries the genetic message or 'blueprint' and is the template that is read.

Concept Tested & Keywords

Concept Tested: Roles of different RNA types in protein synthesis (translation).
Stem keywords: cell translation, ribosome, creates a new protein, strand moves
Lead-in keywords: which strand

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E6 Physiology Guyton 4SAE Part 1 p. 58-60

E6 Harper's Illustrated Biochemistry2023 (pp 26-793 of 813) p. 339-341

Practise the full UP NHM CHO 7 Sept 2022(shift-1st)

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