Biology 9700 · AS & A Level · Protein synthesis

Protein synthesis — practice question

Fig. 3.1 presents the structure of the enzyme lysozyme.
(a(i))[1]

Name the two kinds of covalent bond shown in the structure in Fig. 3.1.

(a(ii))[1]

Fig. 3.1 shows the primary structure of lysozyme. Explain what is meant by the term primary structure.

(b(i))[1]

State what the term hydrolysis means.

(b(ii))[1]

Suggest the kind of biological molecule that acts as the substrate for lysozyme.

(b(iii))[4]

Lysozyme works by the induced fit mechanism. Explain the mode of action of an enzyme that uses the induced fit mechanism.

(c)[1]

Lysozyme acts as an extracellular enzyme in human tears and saliva. State what is meant by the term extracellular.

(d(i))[1]

Use Fig. 3.2 to state the smallest substrate concentration that gives the maximum rate of reaction, $V_{\text{max}}$.

(d(ii))[1]

Use Fig. 3.2 to find the Michaelis-Menten constant, $K_{m}$.

(e)[2]

The investigation was repeated with a competitive inhibitor of lysozyme present. Draw a curve on Fig. 3.2 to represent the expected outcome.

Worked solution & mark scheme

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