Bio chapter 8B
The synthesis of NADPH is catalyzed by which of the following?
NADP+ reductase
Which photosystem's main function is to generate high-energy electrons for the synthesis of ATP?
Photosystem II
Which of the following are phases of the Calvin cycle?
Regeneration of ribulose bisphosphate Reduction and carbohydrate production Carbon fixation
The abbreviation, RuBP, stands for----- 1,5-bisphosphate.
Ribulose
In the Calvin cycle CO2 is attached to an organic molecule abbreviated as---
RuBP
Do C4 and CAM plants also use C3 photosynthesis?
Yes, both C4 and CAM plants also use C3 photosynthesis
The ATP needed in the Calvin cycle comes from
both cyclic and noncyclic photophosphorylation
Plants that only fix carbon using the Calvin cycle are also known as------ plants.
c3
---plants avoid water loss by closing their stomata during the day and opening them at night.
cam
A C3 plant
can only fix carbon using the Calvin cycle
During the fourth stage of the thylakoid reactions, known as ------, protons flow across the membrane down their gradient and in the process ATP is synthesized.
chemiosmosis
The ATP synthases of chloroplasts and mitochondria are
evolutionary related
NADP reductase accepts two electrons from two molecules of __ and catalyzes the production of __.
ferredoxin; NADPH
Photorespiration is considered "wasteful" because
it reduces the yield of photosynthesis. reduces the ability of a plant to make carbohydrates.
The enzyme rubisco has more than one activity. Because of this, most plants also perform----- , which consumes oxygen and liberates carbon dioxide. This process can lower the net benefit from photosynthesis.
photorespiration
Recent studies with the atomic force microscope have shown that PSI and the ATP synthase are not randomly distributed in thylakoid membranes, rather, they seem concentrated
primarily in the connections between grana (the stroma lamellae).
in hot, arid conditions, specialized openings in the leaf called -----close to conserve water, cutting off the supply of carbon dioxide entering the leaf.
stomata
Having two different linked photosystems in chloroplasts overcomes the limitations of anoxygenic photosynthesis by allowing the oxidation of
water
Compared to the C3 pathway, the C4 pathway has an additional cost to a plant, because
ATP is required to convert pyruvate to PEP
Why is the Calvin cycle also known as C3 photosynthesis?
Because the first molecule in the cycle has 3 carbon atoms.
Which of the following differentiates PEP carboxylase from rubisco?
PEP carboxylase does not bind oxygen
The light----reactions of photosynthesis occur on membranes.
dependent
Both PEP carboxylase and rubisco can fix carbon dioxide. However, PEP carboxylase:
does not bind oxygenc4
The C4 pathway has a cost to plants, because the conversion of ----to PEP requires the expenditure of ATP.
pyruvate
What is the name of the enzyme that incorporates CO2 into organic matter during the Calvin cycle?
rubisco
Which of the following represent the phases of the Calvin cycle?
(1) carbon fixation; (2) reduction and carbohydrate production; (3) regeneration of ribulose bisphosphate
How many molecules of CO2 need to be bound to molecules of RuBP to produce 12 molecules of PGA in the Calvin cycle?
6
In the Calvin cycle,----- molecules of CO2 are bound to the same number of RuBP molecules to produce 12 molecules of PGA.
6
What happens during the chemiosmosis stage of the thylakoid reactions?
ATP is synthesized.
The electron transport chain directly associated with photosystem II is used to generate __, while the electron transport chain directly associated with photosystem I is used to generate __.
ATP; NADPH
Why do hot and dry conditions favor photorespiration?
Because plants close their stomata, inhibiting CO2 uptake and increasing O2
Photophosphorylation produces------ , which stores chemical energy that can be used for the Calvin cycle. Carbon fixation also requires reducing power, which is provided by----- produced by photosystem I.
Blank 1: ATP Blank 2: NADPH
The Calvin cycle is also known as------ photosynthesis because the first intermediate of the cycle contains three carbon atoms.
C3
In which type of plant does carbon dioxide capture occur in one cell, and decarboxylation occur in an adjacent cell?
C4 plants
Which of the following is a difference between C4 and CAM plants?
C4 plants use C3 photosynthesis in different cells, while CAM plants use C3 photosynthesis at certain times.
in which type of plant does carbon dioxide capture occur at night, and decarboxylation occur during the day?
CAM plants
How do CAM plants avoid water loss?
CAM plants close their stomata during the day and open them at night.
What molecule is released during photorespiration?
Carbon dioxide
which of the following are phases of the Calvin cycle?
Carbon fixation Reduction and carbohydrate production Regeneration of ribulose bisphosphate
True or false: Glucose is the primary output of the Calvin cycle.
False
True or false: The mechanism of ATP synthesis in the ATP synthase of chloroplasts is fundamentally different from the one used in the ATP synthase of mitochondria.
False
Which of the following is the primary output of the Calvin cycle?
G3P
Where is rubisco located?
In the chloroplast stroma
According to recent studies, where are PSII and the b6-f complexes located?
In the grana and in borders between the grana and the stroma lamellae
Where do the light-dependent reactions of photosynthesis occur in the chloroplast?
In the thylakoid membrane.
How do plants benefit from having two linked photosystems?
It allows them to use electrons from water to reduce NADP+.
Photorespiration has which of the following effects on photosynthesis?
It reduces the yield of photosynthesis.
