Bio 170 quiz 6
How many times must the Calvin cycle turn to yield a single molecule of glyceraldehyde 3-phosphate (G3P)?
3
How many turns of the Calvin cycle would be required for a plant to make one molecule of glucose?
6
Which of the labeled cells of a C3 leaf does not perform photosynthesis?
A and D
Which compounds link the light reactions with the Calvin cycle reactions?
ATP and NADPH
ATP and NADPH are both used during the Calvin cycle. What is the function of each?
ATP supplies energy and NADPH supplies electrons for reducing power.
In which of the labeled cells of a C4 leaf are the Calvin cycle reactions performed?
C only
Not all molecules contain the same amount of chemical energy. What is the energy relationship between G3P and CO2?
G3P has more energy than CO2.
What two things are added to NADP+ to convert it into NADPH?
H+ and electrons
Energy to drive the formation of ATP in photosynthesis is derived from
H+ gradient.
The O2 given off during photosynthesis is derived from which compound?
H2O
The light reactions of photosynthesis are said to be similar to a battery because they form a current. In which direction do the electrons of this circuit flow?
H2O → PSII → electron transport chain → PSI → electron transport chain → NADPH
Replacement electrons for the reaction center of photosystem II are derived from
H2O.
How does ATP synthase obtain the energy to produce ATP?
Hydrogen ions flow down a concentration gradient from the thylakoid space to the stroma through ATP synthase, releasing energy that can be used to produce ATP from ADP + Pi.
In C4 plants, the light reactions will stop during the daytime when the supply of what compound is limited?
NADP+
Which of the following is a coenzyme?
NADP+
Which of the following is not derived from G3P?
NADP+
The _______ from the light reactions is used to reduce CO2 to a carbohydrate using energy derived from ______.
NADPH; ATP
Chlorophyll is to the light reactions as ________ is to the Calvin cycle.
RuBP
Why do plants contain other pigments besides chlorophyll?
The additional pigments are able to absorb other light wavelengths that chlorophyll cannot.
The chlorophyll a molecules in the reaction center of a photosystem participate directly in the capture of solar energy. What is the purpose of the accessory pigments?
They funnel solar energy to chlorophyll a in the reaction center.
A new species of plant is discovered and you are asked to help classify it. Upon examination under a microscope, you find that there is a layer of bundle sheath cells containing chloroplasts around the vein of the leaf of the plant. What can you tell about the plant from this information?
This plant very likely carries out C4 photosynthesis.
Which statement is accurate about how C4 plants are able to survive hot, dry spells during the growing season?
When the stomata close during heat stress, RuBP carboxylase is not exposed to the increase in oxygen concentration experienced in the leaf. This allows the plant to avoid trying to use oxygen.
Which of the following organisms can perform photosynthesis?
algae
In a high latitude rainforest, the dominant type of photosynthesis is most likely to be
c3
RuBP carboxylase (rubisco) is able to bind with both
carbon dioxide and oxygen.
Which steps of photosynthesis does C4 photosynthesis partition in space?
carbon fixation and Calvin cycle reactions
The reaction center of photosystem I consists of what type of molecule?
chlorophyll a
As climate change leads to drier and drier summers in the southeastern United States, more and more homeowners find that they have crabgrass growing in their yards. The reason for this is that
crabgrass is a type of C4 plant that does well in dry climates.
Grana are
flattened sacs of thylakoid membrane.
The function of a photosystem is to
funnel electrons to a central chlorophyll a molecule.
In a redox reaction, reduction means ________, and oxidation means ________.
gain of electrons; loss of electrons
Before being converted into sucrose, starch, or cellulose, G3P must first be converted into which compound?
glucose phosphate
A plant that uses CAM photosynthesis is most likely to be successful in what type of environment?
hot, dry
Which of the following is a disadvantage of C4 photosynthesis relative to C3 photosynthesis?
need for energy to move fixed carbon in C4 compound into bundle sheath cells
The removal of electrons and/or hydrogen atoms from a substrate is called what?
oxidation
Which complex or enzyme of photosynthesis splits H2O?
photosystem II
The addition of electrons and/or hydrogen atoms to a substrate is called what?
reduction
Carotenoids are found in high concentrations in yellow and orange leaves or vegetables. This color is seen because the carotenoid pigments
reflect and transmit yellow and orange wavelengths of light.
The enzyme-rich solution found within the chloroplast is called the
stroma
The difference between bundle sheath cells in C3 and C4 plants is that
the bundle sheath cells in C4 plants have chloroplasts, while those in C3 plants do not.
The localization of the electron transport chains to the thylakoid membrane ensures that
the energy released can be used to establish an H+ ion gradient.
ATP synthase derives energy for the generation of ATP from
the movement of hydrogen ions down their concentration gradient from the thylakoid space to the stroma.
Inside the chloroplasts, chlorophyll is found in the
thylakoid membrane.
The light-harvesting complexes of a chloroplast are located in the ________; the enzymes of the Calvin cycle reactions are located in the ________.
thylakoid membrane; stroma
The innermost compartment of a chloroplast formed by the interconnected thylakoids is the
thylakoid space.
The Calvin cycle reactions only occur in bundle sheath cells in a C4 plant
to shield the Calvin cycle reactions from O2 in the leaf spaces.
During photosynthesis, ________ is oxidized, while ________ is reduced.
water; carbon dioxide
