Exam 8: Photosynthesis: Using Sunlight to Build Carbohydrates

A new experimental pesticide is being tested by a large agricultural chemical company. An unfortunate side effect in plants treated with this new product is a decrease in NADPH production in the chloroplasts. (Interestingly, reduction of NAD⁺ to NADH in the mitochondria is unaffected.) Given this observation, which of the following would you expect to observe in the chloroplasts of these plants?

High temperatures increase reaction rates but lower rubisco selectivity for CO₂ versus O₂. High leaf temperatures thus:

Which of the following sequences accurately represents the flow of electrons through living organisms?

Eukaryotes conduct all of the photosynthesis that occurs in the ocean.

Review the experiment illustrated in Figure 8.6. Based on the result of Experiment #2 and on what you know about photosynthesis, which of the 2D paper chromatography patterns below would be observed if the cells treated with ¹⁴CO₂ had been allowed to remain in culture for a longer period of time before they were put in the boiling alcohol?

Where does the oxygen come from that is produced as a by-product of photosynthesis?

How does the metabolism occurring in chloroplasts differ from that of mitochondria?

In nature, only about 1% to 2% of the sun's usable energy is converted into chemical energy and is stored in carbohydrate. Which of the following contribute to this apparent inefficiency of the photosynthetic process?

The ATP generated by a photosynthetic electron transport chain can be used in the _____ step(s) of the Calvin cycle.

When photosynthesis is fully operational under conditions of intense light, the pH of the thylakoid lumen may be as much as three full pH units lower than the stroma of the chloroplast. Does this mean that the hydrogen ion concentration in the lumen is greater or less than that of the stroma? How many more hydrogen ions are on the side of the thylakoid membrane with the higher concentration compared to the side with the lower concentration?

If a mutation occurs such that photosystem I no longer functions as efficiently as it should, what might be MOST directly affected?

Photorespiration in chloroplasts resembles cellular respiration in mitochondria in that:

Why is the photosynthetic electron transport chain sometimes referred to as the "Z scheme"?

The Z scheme refers to:

The reactions of photosynthesis are an important part of the energy conversion pathways in plants. Suppose you are conducting research on photosynthesis with the following conditions in the plants you are studying: high concentrations of NADPH in the chloroplasts Low concentrations of ATP in the chloroplasts Low intracellular concentrations of glyceraldehyde-3-phosphate (G3P) The plant growing in full sunlight Which of the following statements is TRUE?

Which of the following statements is TRUE regarding reactive oxygen species?

Photorespiration results in the:

A new experimental pesticide is being tested by a large agricultural chemical company. An unfortunate side effect in plants treated with this new product is the partial inhibition of ferredoxin-NADP⁺ reductase. Given this observation, which of the following would you expect to observe in the photosynthetic cells of these plants?

Some of the intermediates in the biosynthesis of chlorophyll are themselves capable of absorbing light energy.

In the Calvin cycle, NADPH is: