Chapter 10: Photosynthesis

G3P is used in which of the following processes? Production of cellulose All of the listed processes can use G3P. Production of glucose Production of cell walls in growing plants Production of starch Production of sucrose

All of the listed processes can use G3P.

Of the following, which occurs during the Calvin cycle? ATP and NADPH are synthesized. Excited electrons are conveyed from chlorophyll to an electron acceptor. Photons are absorbed. Light energy is converted to chemical energy. CO2 is reduced.

CO2 is reduced.

During which process is molecular oxygen produced in photosynthesis? The Calvin cycle during G3P production The light reactions by cyclic electron flow The Calvin cycle during carbon fixation The light reactions by linear electron flow The light reactions by the excitation of electrons in chlorophyll The light reactions by chemiosmosis

The light reactions by linear electron flow

Why are most autotrophs referred to as the producers of the biosphere? They consume other organisms in order to produce organic compounds. All of the listed responses are correct. They produce organic compounds using molecular oxygen. They are the ultimate sources of organic compounds for all nonautotrophic organisms. None of the listed responses is correct. They produce ATP for other organisms.

They are the ultimate sources of organic compounds for all nonautotrophic organisms.

The light reactions of photosynthesis use chemiosmosis to produce ATP that will be used in the Calvin cycle. The electrochemical gradient that drives this chemiosmosis is formed across which structure(s)? Stroma Stomata Thylakoid membrane Cristae Outer membrane of the chloroplast Photosystem II

Thylakoid membrane

Chlorophyll molecules are in which part of the chloroplast? Stroma Stomata Plasma membrane Thylakoid membranes Thylakoid lumen

Thylakoid membranes

Metabolic pathways are typically redox processes. In photosynthesis, what molecule is oxidized and what molecule is reduced? Carbon dioxide is oxidized and water is reduced. Water is oxidized and carbon dioxide is reduced. ADP is oxidized and NADPH is reduced. Glucose is oxidized and oxygen is reduced. Pyruvate is oxidized and NAD+ is reduced. G3P is oxidized and ATP is reduced.

Water is oxidized and carbon dioxide is reduced.

You have a large, healthy philodendron that you carelessly leave in total darkness while you are away on vacation. You are surprised to find that it is still alive when you return. What has the plant been using for an energy source while in the dark? Even though the plant received no visible light, it was able to use the short-wave part of the electromagnetic spectrum (gamma rays and X-rays) to carry out photosynthesis. When light energy is not available, plants can derive energy from inorganic molecules. Even though it can't carry out the light reactions, the plant can still produce sugars because the Calvin cycle doesn't require light. None of the listed responses is correct. While it did have access to light, the plant stored energy in the form of sugars or starch, and it was able to derive energy from the stored molecules during your vacation.

While it did have access to light, the plant stored energy in the form of sugars or starch, and it was able to derive energy from the stored molecules during your vacation.

The most important role of pigments in photosynthesis is to __________. screen out harmful ultraviolet rays catalyze the synthesis of ATP capture light energy store energy catalyze the hydrolysis of water

capture light energy

Carbon dioxide and oxygen enter and exit a leaf by diffusion. Which structure(s) on a leaf allow(s) this process to happen? Stroma Thylakoids Granum Stomata Stem Chloroplast

stomata

How does carbon dioxide enter the leaf? Through the stomata Through the roots Through the chloroplasts Through the vascular system Through the thylakoids

stomata

Where does the Calvin cycle of photosynthesis occur? Stomata Thylakoids Stroma Outer membrane of the chloroplast Granum Mitochondrion

stroma

When chloroplast pigments absorb light, __________. they lose potential energy the Calvin cycle is triggered their photons become excited their electrons become excited they become reduced

their electrons become excited

Both mitochondria and chloroplasts __________. release oxygen as a by-product reduce NAD+, forming NADP obtain electrons from water use chemiosmosis to produce ATP are surrounded by a single membrane

use chemiosmosis to produce ATP

The source of the oxygen produced by photosynthesis has been identified through experiments using radioactive tracers. The oxygen comes from __________. light radioisotopes water carbon dioxide glucose

water

Where do the electrons entering photosystem II come from? Light ATP The electron transport chain Chlorophyll molecules in the antenna complex Water

water

The light reactions of photosynthesis generate high-energy electrons, which end up in __________. The light reactions also produce __________ and __________. water; sugar; oxygen NADPH; ATP; oxygen chlorophyll; ATP; NADPH ATP; NADPH; oxygen oxygen; sugar; ATP

NADPH; ATP; oxygen

In the light reactions of photosynthesis, ATP is produced by photophosphorylation. Which of the listed processes is most similar to photophosphorylation? Oxidative phosphorylation in cellular respiration Glycolysis Citric acid cycle Carbon fixation Photorespiration Calvin cycle

Oxidative phosphorylation in cellular respiration

The energy used to produce ATP in the light reactions of photosynthesis comes from __________. splitting water the oxidation of sugar molecules movement of H+ through a membrane fluorescence carbon fixation

movement of H+ through a membrane

The Calvin cycle could not occur without the light reactions. Which of the following statements describes why this is the case? -ATP and NADPH produced in the light reactions provide the energy for the production of sugars in the Calvin cycle. -RuBP produced in the light reactions facilitates the fixation of carbon from carbon dioxide in the Calvin cycle. -Photons of light produced in the light reactions provide the energy for the production of sugars in the Calvin cycle. -Molecular oxygen produced in the light reactions provides the energy for the production of sugars in the Calvin cycle. -G3P produced in the light reactions is oxidized in the Calvin cycle. -ADP and NADP+ produced in the light reactions provide the energy for the production of sugars in the Calvin cycle.

-ATP and NADPH produced in the light reactions provide the energy for the production of sugars in the Calvin cycle.

The reactions of the Calvin cycle are not directly dependent on light, but they usually do not occur at night. Why? -Carbon dioxide concentrations decrease at night. -At night, no water is available for the Calvin cycle. -The Calvin cycle requires products only produced when the photosystems are illuminated. -Plants usually open their stomata at night. -It is often too cold at night for these reactions to take place.

-The Calvin cycle requires products only produced when the photosystems are illuminated.

A photosystem consists of which of the following structures? Reaction-center complex Primary electron acceptor Chlorophyll molecules Light-harvesting complexes All of the listed structures are parts of a photosystem.

ALL

The light reactions of photosynthesis supply the Calvin cycle with __________. ATP and NADPH. Light energy. CO2 and ATP. Sugar and O2. H2O and NADPH.

ATP and NADPH.

Which of the following statements is a correct distinction between autotrophs and heterotrophs? Only heterotrophs require chemical compounds from the environment. Only heterotrophs require oxygen. Cellular respiration is unique to heterotrophs. Autotrophs, but not heterotrophs, can nourish themselves beginning with CO2 and other nutrients that are inorganic. Only heterotrophs have mitochondria.

Autotrophs, but not heterotrophs, can nourish themselves beginning with CO2 and other nutrients that are inorganic.

What property of the pigment chlorophyll makes it appear green? Chlorophyll reflects all of the colors in the visible spectrum. Chlorophyll absorbs all of the visible spectrum of light except green, which it reflects. Chlorophyll absorbs all light in the visible spectrum and reflects none of them. Chlorophyll reflects blue and yellow light. Chlorophyll reflects red and green light. Chlorophyll absorbs only green light and reflects all of the other colors of the visible spectrum.

Chlorophyll absorbs all of the visible spectrum of light except green, which it reflects.

Which of the following processes occurs during the second phase, the reduction phase, of the Calvin cycle? Carbon fixation ATP production RuBP (ribulose bisphosphate) regeneration NADPH production Molecular oxygen production G3P production

G3P production

During the Calvin cycle, what happens during the carbon fixation phase? G3P is produced. ATP is produced. The Calvin cycle incorporates each CO2 molecule, one at a time, by attaching it to a five-carbon sugar named ribulose bisphosphate. RuBP (ribulose bisphosphate) is regenerated. Molecular oxygen is produced. NADPH is produced.

The Calvin cycle incorporates each CO2 molecule, one at a time, by attaching it to a five-carbon sugar named ribulose bisphosphate.

Which of the following statements correctly describes the difference in carbon fixation between C3 and C4 plants? The first product of carbon fixation in C4 plants is a four-carbon compound instead of a three-carbon compound. C4 plants fix carbon from glucose, but C3 plants do not. There is no difference in carbon fixation between C3 and C4 plants. The first product of carbon fixation in C4 plants is a three-carbon compound. C4 plants use the CAM pathway, but C3 plants do not. C4 plants do not fix carbon from carbon dioxide, but C3 plants do.

The first product of carbon fixation in C4 plants is a four-carbon compound instead of a three-carbon compound.

In photosynthesis, plants use carbon from __________ to make sugar and other organic molecules. chlorophyll carbon dioxide soil the sun water

carbon dioxide

The light reactions of photosynthesis occur in the __________. thylakoids stroma stomata None of the listed responses is correct. inner membrane of the chloroplast mitochondrion

thylakoids