Ch 7 Phoyosynthesis

Which of these equations best summarizes photosynthesis?

6 CO2 + 6 H2O ? C6H12O6 + 6 O2

Where does the Calvin cycle occur?

Stroma.

The light reactions of photosynthesis use _____ and produce _____.

Water...NADPH

Which process produces oxygen?

Photosynthesis

Which set of reactions uses H2O and produces O2?

The light-dependent reactions.

What is the importance of the light-independent reactions in terms of carbon flow in the biosphere?

The light-independent reactions turn CO2, a gas, into usable carbon in the form of sugars.

True or false? The light-dependent reactions of photosynthesis use water and produce oxygen.

True

Which of the following molecules is the primary product of photosystem I?

NADPH

What is the biological significance of the light-independent reactions of photosynthesis?

They convert carbon dioxide to sugar.

Which of the following statements best describes the relationship between the light-dependent and light-independent reactions of photosynthesis?

The light-dependent reactions produce ATP and NADPH, which are then used by the light-independent reactions.

Which of the following reactions ensures that the Calvin cycle can make a continuous supply of glucose?

Regneration of RuBP

Carbon fixation involves the addition of carbon dioxide to _____.

RuBP

After 3-PGA is phosphorylated, it is reduced by _____

NADPH

How many carbon dioxide molecules must be added to RuBP to make a single molecule of glucose?

6

In the Calvin cycle, how many ATP molecules are required to regenerate RuBP from five G3P molecules?

3

In C3 plants the conservation of water promotes _____.

photorespiration

In C4 and CAM plants carbon dioxide is fixed in the _____ of mesophyll cells.

cytoplasm

C4 plants differ from C3 and CAM plants in that C4 plants _____.

transfer fixed carbon dioxide to cells in which the Calvin cycle occurs

Which of the following statements about the Calvin cycle is correct?

The Calvin cycle produces glyceraldehyde 3-phosphate( G3P)3-phosphoglycerate, which can be used to make glucose.

How do C4 plants differ from C3 and CAM plants?

C4 plants fix carbon dioxide away from the site of the Calvin cycle.

True or false? Photorespiration differs from the Calvin cycle in that oxygen is consumed and carbon dioxide is released.

t

Which five-carbon molecule binds to carbon dioxide during the Calvin cycle?

Ribulose bisphosphate

Through which structures do carbon dioxide and water enter plants?

Stomata

How do CAM plants use carbon efficiently in hot, dry climates?

They open their stomata only at night when it is cooler.

Which term describes ATP production resulting from the capture of light energy by chlorophyll?

Photophosphorylation

True or false? The chemiosmotic hypothesis states that the synthesis of ATP generates a proton gradient that leads to electron flow through an electron transport chain.

f

According to the chemiosmotic hypothesis, what provides the energy that directly drives ATP synthesis?

Proton Gradient

Which of the following particles can pass through the ATP synthase channel?

Protons

True or false? The region of ATP synthase that catalyzes the production of ATP from ADP and inorganic phosphate spans the chloroplast membrane.

f

Chloroplast membrane vesicles are equilibrated in a simple solution of pH 5. The solution is then adjusted to pH 8. Which of the following conclusions can be drawn from these experimental conditions?

ATP will not be produced because there is no ADP and inorganic phosphate in the solution.

Select the correct molecule that is the main product of the Calvin cycle.

G3P

What is the basic role of CO2 in photosynthesis?

CO2 is fixed or incorporated into organic molecules.

Select the most accurate statement describing the basic function of the light reactions of photosynthesis.

The basic function of the light reactions of photosynthesis is the conversion of solar energy to chemical energy.

Select the correct statement about the Calvin cycle.

The Calvin cycle has three phases: carbon fixation, reduction, and regeneration of RuBP.

Why are plants classified as producers?

because they fix inorganic carbon into organic molecules.

photosynthetic membranes are found in the _____ in plant cells.

chloroplasts

The light reactions of photosynthesis supply the Calvin cycle with

ATP and NADPH

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

H2O ? NADPH ? Calvin cycle

How is photosynthesis similar in C4 plants and CAM plants?

In both cases, rubisco is not used to fix carbon initially.

Which of the following statements is a correct distinction between autotrophs and heterotrophs?

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

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

release of oxygen

In mechanism, photophosphorylation is most similar to

oxidative phosphorylation in cellular respiration.

Which process is most directly driven by light energy?

removal of electrons from chlorophyll molecules

Plants are photoautotrophs. What does this mean?

They use light energy to drive the synthesis of organic molecules from inorganic materials.

The ultimate source of energy to support most life on Earth is _____.

sunlight

C4 plants occur more commonly in desert conditions because _____.

they can fix carbon at the lower CO2 concentrations that develop when the stomata are closed

The overall function of the Calvin cycle is _____.

making sugar

Which of the following products of the light reactions of photosynthesis is consumed during the Calvin cycle?

NADPH

In the electromagnetic spectrum, the type of radiation that we call visible light occurs between _____.

ultraviolet radiation and infrared radiation

Which of the following is a product of the light reactions of photosynthesis?

oxygen, ATP, and NADPH

When light strikes chlorophyll molecules, they lose electrons, which are ultimately replaced by _____.

splitting water

Photosynthesis is a redox reaction. This means that H2O is _____ during the light reactions and CO2 is _____ during the Calvin cycle.

oxidized...reduced