A patient has a bacterial infection of the cornea. Researchers test three antibiotics at concentrations that can reach the cornea.
The table shows the results after 24 hours.
| Antibiotic | Process inhibited | Bacterial population (% of population at start) | Human corneal cells surviving (%) |
|---|---|---|---|
| D | bacterial cell-wall synthesis | 12 | 99 |
| E | protein synthesis in bacterial and human cells | 6 | 58 |
| F | bacterial DNA replication | 24 | 97 |
Explain why the results support choosing antibiotic D rather than antibiotic E or F for this patient.
A second pathogen infecting the cornea is a virus.
Explain why antibiotic D will not stop this virus reproducing.
87 exam-style questions on Edexcel GCSE Biology 5.3 Immune system and medicines, covering 5.3.1 The specific immune system, 5.3.2 Response to immunisation, 5.3.3 Advantages and disadvantages of immunisation, 5.3.4 Antibiotics and bacterial infections, 5.3.5 Aseptic techniques in culturing, 5.3.6 Cross-sectional areas of cultures, 5.3.7 Stages of developing new medicines, and 5.3.8 Production of monoclonal antibodies. Each one has a worked solution and a mark scheme showing where the marks go.