Biology Answers

1.6) In comparing the light reaction with the Calvin cycle of photosynthesis in plants which  of them produces NADPH?

1. Neither the light reactions nor the Calvin cycle
2. Light reaction alone
3. Occurs in the chloroplast but is not part of photosynthesis
4. The Calvin cycle alone
5. Both the light reactions and the Calvin cycle

1.6) Which of the events listed below occur in the light reactions of photosynthesis?

1. ATP is phosphorylated to yield ADP
2. Light is absorbed and funnelled to reaction-centre chlorophyll a.
3. NADP is produced
4. Carbon dioxide is incorporated into PGA
5. NADPH is reduced to NADP⁺

1.6)In the thylakoid membranes, what is the main role of the light-harvesting complex?

1. Synthesize ATP from ADP and Pi
2. Concentrate photons within the stroma
3. Harvest photons and transfer light energy to the reaction-centre chlorophyll
4. Split water and release oxygen to the reaction-centre chlorophyll
5. Transfer electrons to ferredoxin and then NADPH

1.6) Where does the Calvin cycle take place?

1. Outer membrane of the chloroplast
2. Cytoplasm surrounding the chloroplast
3. Thylakoid membrane
4. Chlorophyll molecule
5. Stroma of the chloroplast

Give an account of the effect of temperature and pH on the activity of enzyme

1.6) Where does the Calvin cycle take place?

1. Outer membrane of the chloroplast
2. Cytoplasm surrounding the chloroplast
3. Thylakoid membrane
4. Chlorophyll molecule
5. Stroma of the chloroplast

1.6) What are the products of the light reactions that are subsequently used by the Calvin cycle?

1. Carbon dioxide and RuBP
2. Water and carbon
3. Electrons and photons
4. Oxygen and carbon dioxide
5. ATP and NADPH

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