Chapter 10: Photosynthesis

In the Calvin cycle, how many ATP molecules are required to regenerate RuBP from five G3P molecules? 4 2 5 1 3

3

How many carbon dioxide molecules must be added to RuBP to make a single molecule of glucose? 10 8 4 6 2

6

Which of these equations best summarizes photosynthesis? C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + Energy 6 CO2 + 6 H2O → C6H12O6 + 6 O2 H2O → 2 H+ + 1/2 O2 + 2e- C6H12O6 + 6 O2 → 6 CO2 + 12 H2O 6 CO2 + 6 O2 → C6H12O6 + 6 H2O

6 CO2 + 6 H2O → C6H12O6 + 6 O2

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

ATP and NADPH.

What is the basic role of CO2 in photosynthesis? CO2 is fixed or incorporated into organic molecules. CO2 is taken in by plants as a form of inverse respiration, in which carbon dioxide is "breathed in" and oxygen is "breathed out." CO2 is a source of electrons in the formation of organic molecules.

CO2 is fixed or incorporated into organic molecules.

After 3-PGA is phosphorylated, it is reduced by _____. ATP NADP+ NADPH CO2 ADP

NADPH

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.

False

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

False

How is photosynthesis similar in C4 plants and CAM plants? In both cases, thylakoids are not involved in photosynthesis. In both cases, rubisco is not used to fix carbon initially. In both cases, only photosystem I is used. Both types of plants make most of their sugar in the dark. Both types of plants make sugar without the Calvin cycle.

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

Which of the following molecules is the primary product of photosystem I? NADPH Oxygen Carbon dioxide ATP

NADPH

Paper chromatography is a technique used to separate molecules based upon their size and solubility in a particular solvent. If pigments from a particular species of plant are extracted and subjected to paper chromatography, which of the following results is most likely? Paper chromatography would separate the pigments into several bands that appear green or yellow/orange. Paper chromatography would produce a single band of pigment that is characteristic of that particular plant. Paper chromatography would separate the pigments into two bands, one that appears blue and one that appears red. Paper chromatography would separate the pigments into two bands that appear green.

Paper chromatography would separate the pigments into several bands that appear green or yellow/orange.

_____ has a longer wavelength than _____ Yellow ... red Blue ... green Green ... yellow Red ... green Violet ... blue

Red... green

Carbon fixation involves the addition of carbon dioxide to _____ NADPH G3P 3-PGA Rubisco RuBP

RuBP

Which molecule is regenerated in the regeneration phase of the Calvin cycle? Without regeneration of this molecule, the Calvin cycle would stop. RuBP G3P ATP 3-phosphoglycerate

RuBP

Select the correct statement about the Calvin cycle. The basic function of the Calvin cycle is the conversion of solar energy to chemical energy. The Calvin cycle takes place primarily in the dark. The Calvin cycle has three phases: carbon fixation, reduction, and regeneration of RuBP.

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

Which set of reactions uses H2O and produces O2? The light-independent reactions The light-dependent reactions

The light-dependent reactions

Which of the following statements best describes the relationship between the light-dependent and light-independent reactions of photosynthesis? The light-independent reactions release energy, and the light-dependent reactions require energy. The light-dependent reactions produce carbon dioxide, which is then used by the light-independent reactions. The light-dependent reactions produce ATP and NADPH, which are then used by the light-independent reactions. The light-dependent reactions pass electrons through an electron transport chain to the light-independent reactions.

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

What is the importance of the light-independent reactions in terms of carbon flow in the biosphere? The light-independent reactions turn glucose, a sugar, into CO2 gas. The light-independent reactions turn CO2, a gas, into usable carbon in the form of sugars. The light-independent reactions turn sugar into ATP for energy. The light-independent reactions use CO2 to make ATP.

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

Plants are photoautotrophs. What does this mean? They are the primary consumers of the biosphere. They are attracted to light. They synthesize their own food from inorganic materials. They use light energy to drive the synthesis of organic molecules from inorganic materials. They generate oxygen.

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

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

True

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

True

In C4 and CAM plants carbon dioxide is fixed in the _____ of mesophyll cells. thylakoids grana cytoplasm stomata stroma

cytoplasm

CAM plants keep stomata closed in the daytime, thus reducing loss of water. They can do this because they ____ use photosystem I and photosystem II at night fix CO2 into pyruvate in the mesophyll cells fix CO2 into sugars in the bundle-sheath cells fix CO2 into organic acids during the night

fix CO2 into organic acids during the night

In which of the following organisms did the process of photosynthesis most likely originate? in plants in fungi in prokaryotes three separate times during evolution

in prokaryotes

The overall function of the Calvin cycle is _____. splitting water producing carbon dioxide capturing sunlight making sugar oxidizing glucose

making sugar

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

oxidized...reduced

Which of the following is a product of the light reactions of photosynthesis? high-energy photons glyceraldehyde-3-phosphate water and CO2 oxygen, ATP, and NADPH NADP+ and RuBP

oxygen, ATP and NADPH

Which term describes ATP production resulting from the capture of light energy by chlorophyll? Substrate-level phosphorylation Oxidative phosphorylation Photophosphorylation Dephosphorylation

photophosphorylation

In C3 plants the conservation of water promotes _____ photosynthesis photorespiration a shift to C4 photosynthesis the opening of stomata the light reactions

photorespiration

Which process produces oxygen? Photosynthesis Cellular respiration

photosynthesis

In photosynthetic cells, synthesis of ATP by chemiosmosis occurs during ________ photosynthesis and respiration respiration only photosynthesis only photosynthesis, respiration, and fermentation

photosynthesis and respiration

According to the chemiosmotic hypothesis, what provides the energy that directly drives ATP synthesis? Electrons Osmotic gradient Temperature gradient Proton gradient

proton gradient

Which of the following particles can pass through the ATP synthase channel? ATP ADP Protons Inorganic phosphate

protons

Which of the following processes is most directly driven by light energy? removal of electrons from chlorophyll molecules creation of a pH gradient by pumping protons across the thylakoid membrane carbon fixation in the stroma reduction of NADP+ molecules

removal of electrons from chlorophyll molecules

When light strikes chlorophyll molecules, they lose electrons, which are ultimately replaced by _____. breaking down ATP splitting water oxidizing glucose removing them from NADPH fixing carbon

splitting water

Where in a plant cell does the Calvin cycle take place? interior of the thylakoid (thylakoid space) thylakoid membrane stroma of the chloroplast outer membrane of the chloroplast

stroma of the chloroplast

The ultimate source of energy to support most life on Earth is _____. the carbon cycle photosynthetic plants geothermal heat chemosynthetic microbes sunlight

sunlight

C4 plants differ from C3 and CAM plants in that C4 plants _____ use malic acid to transfer carbon dioxide to the Calvin cycle transfer fixed carbon dioxide to cells in which the Calvin cycle occurs use PEP carboxylase to fix carbon dioxide are better adapted to wet conditions open their stomata only at night

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

The light reactions of photosynthesis use _____ and produce _____. water ... NADPH NADPH ... NADP+ carbon dioxide ... sugar carbon dioxide ... oxygen NADPH ... oxygen

water... NADPH