Molecular Biology Answers

1.6) With regard to respiratory electron transport in the inner membrane of the mitochondria which statement is INCORRECT?

1. Oxygen is the electron acceptor
2. NADH is the electron donor
3. Coenzyme Q functions as both an electron carrier and transmembrane proton shuttle agent
4. NAD⁺ is an electron acceptor
5. H₂O is a product one of the redox reactions.

1.6) For a single pyruvate molecule entering the mitochondrial respiratory metabolic pathway, which statement is INCORRECT?

1. Three CO₂ molecules are produced
2. Only two CO2 molecules are produced
3. Four NAD⁺s are reduced
4. Two CO₂ molecules are produced by reactions in the citric acid cycle
5. One ATP is produced by a substrate phosphorylation associated with the citric acid cycle.

1.6) How many of the following molecules are produced during two turns of the Citric acid cycle of cellular respiration?

(a) 2 x NADH, 2 x CO_2, 1 x FADH₂

(b) 3 x NADH, 2 x CO_2, 1 x FADH₂

(c) 6 x NADH, 2 x CO2_, 1 x O2, 2 x ATP

(d) 6 x NADH, 4 x CO_2, 2 x FADH₂, 2 x ATP

(e) 4 x NADH, 4 x CO_2, 2 x FADH₂, 2 x citrate

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

What is the first thing to do after putting a weighing boat on the balance?