Biology Answers

In cellular respiration, when pyruvate is converted to acetyl Co A the following is formed:

1. Reduced NAD+ only
2. Reduced NAD+ and CO₂
3. Reduced NAD and ATP
4. CO₂ and ATP only
5. CO₂, reduced NAD and ATP

1.6) (i) Glycolysis, (ii) the conversion of pyruvate to Acetyl CoA, (iii) the citric acid cycle and electron transport chain respectively give a net yield of the following number of ATP molecules

1. 7, 5, 20
2. 5, 3, 20
3. 6, 6, 24
4. 6, 4, 26
5. 4, 8, 24

1.6) State the functions of each of the three phases of the Calvin cycle.

1.6) Describe the similarities and differences in chemiosmosis between oxidative phosphorylation in mitochondria and photophosphorylation in chloroplast

1.6) Trace, using a diagram, the movement of electrons in i) noncyclic electron flow and ii) cyclic electron flow.

1.6) Differentiate between cyclic and non-cyclic photophosphorylation in photosynthesis.

1.6) The light phase of photosynthesis involves the activation of PS I and PS II. Describe the composition of these photosystems and the mechanisms in place used to trap light energy.

1. Explain why it is not possible to state an exact number of ATP molecules generated by the oxidation of glucose.

1.6) Write a balanced equation showing the conversion of glucose and oxygen to carbon dioxide and water:

(a) Indicate in your equation which molecule becomes reduced?  

(b) Indicate in your equation which molecule becomes oxidized?

(c) What happens to the energy that is released in this redox reaction?

(d) Name the oxidizing agent.

1.6) Discuss Mitchell’s chemiosmotic hypothesis of ATP generation in mitochondria (discuss the roles of the electron transport chain, proton gradient and ATP synthase complex).