Biology 9700 · AS & A Level · Protein synthesis

Protein synthesis — practice question

DNA and RNA are essential biological molecules that take part in the synthesis of polypeptides.
(a(i))[1]

Fig. 4.1 shows a section of a DNA molecule rather than a section of an RNA molecule. Explain why.

(a(ii))[1]

Name the covalent bond that joins the two nucleotides.

(a(iii))[1]

Name the component labelled X.

(b)[2]

Outline the role of transfer RNA (tRNA) in polypeptide synthesis.

(c)[3]

Describe how a peptide bond is produced between two amino acids during polypeptide synthesis.

Worked solution & mark scheme

This 8-mark question has a full step-by-step worked solution and mark scheme. One marking point: It is identified as DNA since RNA does not contain thymine.

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