Biology 9700 · AS & A Level · Principles of genetic technology
Principles of genetic technology — practice question
Gold ions ($\text{Au}^{3+}$) are poisonous to most microorganisms. Even so, the bacterium Delftia acidovorans is often found in layers known as biofilms that develop on the surface of gold deposits.
D. acidovorans makes a peptide synthase that catalyses the formation of a small peptide named delftibactin. Once isolated, delftibactin can cause $\text{Au}^{3+}$ ions to precipitate as tiny particles of metallic gold.
(a)[3]
Name one other secondary metabolite and explain what is meant by this term.
(b)[3]
Using Fig. 2.1, suggest how delftibactin protects D. acidovorans from toxic $\text{Au}^{3+}$ ions.
(c)[4]
Explain whether the results in Fig. 2.2 do or do not support the view that delftibactin is protective.
(d)[5]
The secondary metabolite, delftibactin, could be used to remove the toxic $\text{Au}^{3+}$ ions present in waste from gold mining. Describe how delftibactin could be produced on a large scale.
Worked solution & mark scheme
This 15-mark question has a full step-by-step worked solution and mark scheme. One marking point: “penicillin or any other named antibiotic” …