BIOL 1020 Chapter 10 Mastering Biology
What is the output of the Calvin Cycle?
NAD+, ADP, and G3P
The photosynthetic membranes are found in the _____ in plant cells.
chloroplasts
In a plant, which of the following reactions produce molecular oxygen (O2)?
the light reactions alone
What is the biological significance of the light-independent reactions of photosynthesis?
they convert carbon dioxide to sugar
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
In the Calvin cycle, how many ATP molecules are required to regenerate RuBP from five G3P molecules?
3
How many carbon dioxide molecules must be added to RuBP to make a single molecule of glucose?
6
Which of these equations best summarizes photosynthesis?
6 CO2 + 6 H2O → C6H12O6 + 6 O2
The light reactions of photosynthesis supply the Calvin cycle with...
ATP and NADPH
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
What is the input of the Calvin Cycle?
ATP, NADPH, and O2
What is the output of light reactions?
ATP, NADPH, and O2
What is the basic role of CO2 in photosynthesis?
CO2 is fixed or incorporated into organic molecules
The electrons derived from this oxidation reaction in the Calvin cycle are used to reduce _______ to _______.
CO2; G3P
Which of the following sequences correctly represents the flow of electrons during photosynthesis?
H2O → NADPH → Calvin cycle
In the light reactions, light energy is used to oxidize _____ to _____.
H2O; O2
Which molecule is the final electron acceptor for electrons from photosystem I?
NAD+
The electrons derived from this oxidation reaction in the light reactions are used to reduce ______ to _______.
NAD+; NADPH
After 3-PGA is phosphorylated, it is reduced by _____.
NADPH
The Calvin cycle oxidizes the light-reactions product _________ to ________.
NADPH; NAD+
Carbon fixation involves the addition of carbon dioxide to _____.
RuBP
A flask containing photosynthetic green algae and a control flask containing water with no algae are both placed under a bank of lights that is 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 ________.
be higher in the light, but lower in the dark
Why are plants classified as producers?
because they fix inorganic carbon into organic molecules
Compared to C3 plants, C4 plants _____.
can continue to fix CO2 even at lower CO2 concentrations and higher oxygen concentrations
In C4 and CAM plants carbon dioxide is fixed in the _____ of mesophyll cells.
cytoplasm
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, rubisco is not used to fix carbon initially
In autotrophic bacteria, where is chlorophyll located?
in infolded regions of the plasma membrane
What is the input of light reactions?
light, water, ADP, and NAD+
Which set of reactions uses H2O and produces O2? a) the light-independent reactions b) the light-dependent reactions
light-dependent reactions
The overall function of the Calvin cycle is _____.
making sugar
In mechanism, photophosphorylation is most similar to...
oxidative phosphorylation in cellular respiration
The mechanism of photophosphorylation is most similar to which of the following processes?
oxidative phosphorylation in cellular respiration
Photosynthesis is a redox reaction. This means that H2O is _____ during the light reactions and CO2 is _____ during the Calvin cycle.
oxidized; reduced
Which of the following is a product of the light reactions of photosynthesis?
oxygen, ATP, and NADPH
Which term describes ATP production resulting from the capture of light energy by chlorophyll?
photophosphorylation
In C3 plants the conservation of water promotes _____.
photorespiration
Which process produces oxygen? a) Photosynthesis b) Cellular Respiration
photosynthesis
In photosynthetic cells, synthesis of ATP by chemiosmosis occurs during ________.
photosynthesis and respiration
Under what conditions do photosynthesis and cellular respiration occur in plants?
photosynthesis occurs only in the light, and cellular respiration occurs in both the dark and the light
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
Which of the following processes is directly associated with photosystem I?
receiving electrons from the thylakoid membrane electron transport chain
In the initial step in carbon fixation, a molecule of CO2 is attached to RuBP to produce a six-carbon molecule, which is immediately split to produce two molecules of 3-phosphoglycerate. After phosphorylation and reduction produces glyceraldehyde 3-phosphate (G3P), what more needs to occur to complete the Calvin cycle?
regeneration of RuBP
Which of the following reactions ensures that the Calvin cycle can make a continuous supply of glucose?
regneration of RuBP
Which of the following does not occur during the Calvin cycle?
release of oxygen
Where in a plant cell does the Calvin cycle take place?
stroma of the chloroplast
The ultimate source of energy to support most life on Earth is _____.
sunlight
Which of the following processes would be most directly affected if a thylakoid membrane is punctured so that the interior of the thylakoid is no longer separated from the stroma?
synthesis of ATP
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
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
What is the function of the pigment molecules in a light-harvesting complex in the thylakoid membranes?
they absorb and transfer light energy to the reaction-center chlorophyll
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
Plants are photoautotrophs. What does this mean?
they use light energy to drive the synthesis of organic molecules from inorganic materials
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 process is most directly driven by light energy?
transfer of energy from pigment molecule to pigment molecule
The light reactions of photosynthesis use _____ and produce _____.
water; NADPH
