Chapter 10 Practice Questions

The process of photosynthesis probably originated in

In autotrophic bacteria, where is chlorophyll located?

Plants photosynthesize

Early investigators thought the oxygen produced by photosynthetic plants came from carbon dioxide, it come from

If photosynthesizing green algae are provided with CO2 containing heavy oxygen (18O), later analysis will show that all of the following molecules produced by the algae contain 18O

Every ecosystem must have

When oxygen is released as a result of photosynthesis, it is a direct-by-product of

Autotrophs vs Heterotrophs

Why are the absorption spectrum for chlorophyll a and the action spectrum for photosynthesis different?

What wavelength of light in the figure is most effective in driving photosynthesis?

why are there several structurally different pigments in the reaction centers of photosystems?

if pigments from a particular species of plant are extracted and subjected to paper chromatography, which of the following is most likely?

In autumn, the leaves of deciduous trees change colors. This is because chlorophyll is degraded and _____.

What event accompanies energy absorption by chlorophyll (or other pigment molecules of the antenna complex)?

As electrons are passed through the system of electron carriers associated with photosystem II, they lose energy. What happens to this energy?

The final electron acceptor associated with photosystem I is _____.

The electrons of photosystem II are excited and transferred to electron carriers. From which molecule or structure do the photosystem II replacement electrons come?

In the thylakoid membranes, the pigment molecules in a light-harvesting complex _____.

Which of the following are directly associated with photosystem I?

Some photosynthetic organisms contain chloroplasts that lack photosystem II, yet are able to survive. The best way to detect the lack of photosystem II in these organisms would be to _____.

What are the products of linear electron flow?

As a research scientist, you measure the amount of ATP and NADPH consumed by the Calvin cycle in 1 hour. You find that 30,000 molecules of ATP were consumed, but only 20,000 molecules of NADPH were consumed. Where did the extra ATP molecules come from?

Assume a thylakoid is somehow punctured so that the interior of the thylakoid is no longer separated from the stroma. This damage will most directly affect the _____.

In a plant cell, where are the ATP synthase complexes located?

In mitochondria, chemiosmosis moves protons from the matrix into the intermembrane space, whereas in chloroplasts, chemiosmosis moves protons from the _____.

Which of the following statements best describes the relationship between photosynthesis and respiration?

In photosynthetic cells, synthesis of ATP by the chemiosmotic mechanism occurs during _____.

Carbon dioxide is split to form oxygen gas and carbon compounds _____.

What is the relationship between the wavelength of light and the quantity of energy per photon?

P680+ is said to be the strongest biological oxidizing agent. Given its function, why is this necessary?

Carotenoids are often found in foods that are considered to have antioxidant properties in human nutrition. What related function do they have in plants?

In a plant, the reactions that produce molecular oxygen (O2) take place in _____.

The accumulation of free oxygen in Earth's atmosphere began with the origin of _____.

In its mechanism, photophosphorylation is most similar to _____.

Which process is most directly driven by light energy?

A gardener is concerned that her greenhouse is getting too hot from too much light and seeks to shade her plants with colored translucent plastic sheets, the color of which allows passage of only that wavelength. What color should she use to reduce overall light energy but still maximize plant growth?

A flask containing photosynthetic green algae and a control flask containing water with no algae are both placed under a bank of lights, which are set to cycle between 12 hours of light and 12 hours of dark. The dissolved oxygen concentrations in both flasks are monitored. Predict what the relative dissolved oxygen concentrations will be in the flask with algae compared to the control flask. The dissolved oxygen in the flask with algae will _____.

Which of the following are products of the light reactions of photosynthesis that are utilized in the Calvin cycle?

Where does the Calvin cycle take place?

What is the primary function of the Calvin cycle?

In the process of carbon fixation, RuBP attaches a CO2 to produce a six-carbon molecule, which is then split to produce two molecules of 3-phosphoglycerate. After phosphorylation and reduction produces glyceraldehyde 3-phosphate (G3P), what more needs to happen to complete the Calvin cycle?

Which of the following does NOT occur during the Calvin cycle?

What compound provides the reducing power for Calvin cycle reactions?

What would be the expected effect on plants if the atmospheric CO2 concentration was doubled?

Why are C4 plants able to photosynthesize with no apparent photorespiration?

CAM plants keep stomata closed in the daytime, thus reducing loss of water. They can do this because they _____.

The alternative pathways of photosynthesis using the C4 or CAM systems are said to be compromises. Why?

If plant gene alterations cause plants to be deficient in photorespiration, what would most probably occur?

Compared to C3 plants, C4 plants _____.

In autotrophic bacteria, where are the enzymes located that can carry on organic synthesis?

A plant has a unique photosynthetic pigment. The leaves of this plant appear to be reddish yellow. What wavelengths of visible light are being absorbed by this pigment?

What did Engelmann conclude about the congregation of bacteria in the red and blue areas?

An outcome of this experiment was to help determine

If you ran the same experiment without passing light through a prism, what would you predict?

Compared with the lines for chlorophyll a in the figure, where would you expect to find the lines to differ for chlorophyll b?

he reaction-center chlorophyll of photosystem I is known as P700 because

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

Which statement describes the functioning of photosystem II?

Suppose the interior of the thylakoids of isolated chloroplasts were made acidic and then transferred in the dark to a pH-8 solution. What would be likely to happen?

Reduction of oxygen which forms water occurs during

Reduction of NADP+ occurs during

Generation of proton gradients across membranes occurs during

In a protein complex for the light reaction (a reaction center), energy is transferred from pigment molecule to pigment molecule, to a special chlorophyll a molecule, and eventually to the primary electron acceptor. Why does this occur?

P680+ is said to be the strongest biological oxidizing agent. Why?

Some photosynthetic bacteria (e.g., purple sulfur bacteria) have photosystem I but not II, while others (e.g. cyanobacteria) have both PSI and PSII. Which of the following might this observation imply?

Cyclic electron flow may be photoprotective (protective to light-induced damage). Which of the following experiments could provide information on this phenomenon?

n thylakoids, protons travel through ATP synthase from the stroma to the thylakoid space. Therefore the catalytic ʺknobsʺ of ATP synthase would be located

Which of the following statements best represents the relationships between the light reactions and the Calvin cycle?

Where do the enzymatic reactions of the Calvin cycle take place?

Produces molecular oxygen (O2)

Requires ATP

Produces NADH

Produces NADPH

Produces three carbon sugars

requires CO2

requires glucose

The sugar that results from three ʺturnsʺ of the Calvin cycle is glyceraldehyde-3-phosphate (G3P). Which of the following is a consequence of this?

In the process of carbon fixation, RuBP attaches a CO2 to produce a 6 carbon molecule, which is then split in two. After phosphorylation and reduction, what more needs to happen in the Calvin cycle?

In metabolic processes of cell respiration and photosynthesis, prosthetic groups such as heme and iron-sulfur complexes are encountered. What do they do?

The pH of the inner thylakoid space has been measured, as have the pH of the stroma and of the cytosol of a particular plant cell. Which, if any, relationship would you expect to find?

In an experiment studying photosynthesis performed during the day, you provide a plant with radioactive carbon (14C) dioxide as a metabolic tracer. The 14C is incorporated first into oxaloacetate. The plant is best characterized as a

CAM plants keep stomata closed in daytime, thus reducing loss of water. They can do this because they

Photorespiration lowers the efficiency of photosynthesis by preventing the formation of

If plant gene alterations cause the plants to be deficient in photorespiration, what would most probably occur?

The light reactions of photosynthesis supply the Calvin cycle with

Which of the following sequences correctly represents the flow of electrons during photosynthesis?

In mechanism, photophosphorylation is most similar to

How is photosynthesis similar in C4 and CAM plants?