Paper 1: Advanced Biochemistry, Microbiology and Genetics

Which bond joins the two glucose molecules in maltose?

Compare the structures of amylose and cellulose.

Describe how a triglyceride is formed.

Which bonds in the tertiary structure of a protein are most easily broken by a small rise in temperature?

In an enzyme experiment, 0, 6, 11, 15 and 18 µmol of product had formed after 0, 1, 2, 3 and 4 minutes. Calculate the initial rate of reaction.

Explain how end-product inhibition regulates a metabolic pathway.

Describe how you could investigate the effect of temperature on the rate of a catalase-controlled reaction.

Describe the lytic cycle of a bacteriophage.

Give the function of each of the following in a bacterial cell: plasmid, flagellum, capsule.

A bacterium measures 2.5 µm long. In a photograph it measures 50 mm. Calculate the magnification, showing your working.

Give three differences between mitosis and meiosis.

Describe double fertilisation in a flowering plant.

Explain the role of the acrosome reaction.

Describe the link reaction and the Krebs cycle.

Explain how ATP is produced by chemiosmosis in mitochondria.

In a respirometer, woodlice took up 0.84 cm³ of oxygen in 12 minutes. The total mass of the woodlice was 1.4 g. Calculate the rate of oxygen uptake in cm³ g⁻¹ h⁻¹.

Explain what happens to lactate after a period of intense exercise.

Which of the following is produced by the photolysis of water?

Compare cyclic and non-cyclic photophosphorylation.

Figure 1 shows the concentrations of GP and RuBP in a chloroplast suspension. The light was switched off at 10 minutes. Explain the changes in GP and RuBP after the light is switched off.

Describe how thin-layer chromatography can be used to separate photosynthetic pigments.

Describe three aseptic techniques used when culturing bacteria, and why each is used.

A culture was diluted to 10⁻⁵ and 0.1 cm³ of the dilution was spread onto an agar plate. After incubation, 37 colonies grew. Calculate the number of bacteria per cm³ in the original culture.

Figure 2 shows the growth of a bacterial population. Describe and explain the changes between 0 and 28 hours.

Distinguish between bactericidal and bacteriostatic antibiotics, and explain how hospitals can reduce the spread of antibiotic-resistant bacteria.

Explain the role of each temperature stage in the polymerase chain reaction.

Describe how gel electrophoresis separates DNA fragments.

Describe how bacteria can be genetically modified to produce human insulin.

Give one argument for and one against growing genetically modified crops.

Describe how Mycobacterium tuberculosis causes disease and how it avoids the immune system.

Explain the role of T killer cells.

For a disease with a basic reproduction number R₀ = 5, the proportion of the population that must be immune for herd immunity is 1 - 1/R₀. Calculate this percentage and explain what it means.

Discuss whether the overuse of antibiotics in farming is a risk to human health.