Ch. 7 Photosynthesis
The Calvin cycle uses more _________ than __________
ATP; NADPH
The electron transport chain directly associated with PSII is used to generate ______, while the electron transport chain directly associated with PSI is used to generate ______.
ATP; NADPH
Why is light considered a form of electromagnetic radiation?
Because it consists of both electric and magnetic energy
Why might plants contain a variety of pigments?
Because this feature enables plants to absorb light at many different wavelengths
______ plants only uptake CO2 at night because they close their ______ during the day.
CAM; stomata
What molecule is reduced during the process of photosynthesis?
CO2
In the first phase of the ______, atmospheric carbon dioxide is fixed into a five carbon sugar.
Calvin cycle
The stroma of the chloroplast is the site where the ______ takes place
Calvin cycle
The stroma of the chloroplast is the site where the ______ takes place.
Calvin cycle
True or false: Glucose is the primary output of the Calvin cycle.
False
Which of the following are products of the light reactions of photosynthesis that are used as reactants in the Calvin cycle?
NADPH ATP
The products of the light reactions of photosynthesis are _________, _________, and ________.
NADPH, ATP, Oxygen
In some C4 plants, PEP carboxylase and rubisco function in different cells to minimize the effects of photorespiration. Where are these two enzymes located?
PEP carboxylase is in mesophyll cells, and rubisco is in bundle-sheath cells.
In the last phase of the Calvin cycle, what molecule is regenerated so that the next cycle can occur?
Ribulose bisphosphate
What two chemical reactions are catalyzed by rubisco?
RuBP + CO2 → 2 3PG RuBP + O2 → 3PG + phosphoglycolate
Which of following best describes the location of chlorophyll a and b within the chloroplasts of green plants?
Thylakoid membrane
True or false: Photosystem II is the only known protein complex that can oxidize water resulting in the release of O2.
True
During photosynthesis in green plants, what molecule is oxidized?
Water
The ______ scheme describes the energy transitions of electrons as they move through the ______ reactions.
Z; light
When light strikes an object, the light may pass through the object, have its direction changed by the object (reflected), or be ____________ by the object.
absorbed
Organisms that are able to make organic molecules from inorganic sources, such as carbon dioxide and water, are called ________
autotrophs
A key difference between linear electron flow and cyclic electron flow is that in cyclic electron flow, electrons are ultimately transferred:
back to PSI
Light is a type of ______ radiation because it consists of energy in the form of electric and magnetic fields.
electromagnetic
When an electron absorbs energy, it becomes _________
excited
The production of glucose from carbon dioxide and water is an _________ reaction that releases a large amount of free energy.
exergonic
All photons contain the same amount of energy.
false
Electrons in an excited state can release energy as __________or __________ or be transferred to another molecule.
heat light
According to the Z-scheme, electrons:
increase and decrease their energy as they move through the light reactions
Autotrophs sustain themselves by producing organic molecules from:
inorganic molecules
Every photon contains a specific amount of ________
light energy
Photosynthesis is divided into two stages: the _______ reactions and the __________ cycle.
light reactions calvin cycle
In the light reactions, roughly equal amounts of ATP and NADPH are made. However, the Calvin cycle requires
more ATP than NADPH
During photosynthesis, NADPH is synthesized by:
photosystem I
During linear electron flow, the movement of electrons occurs from water to
photosystem II, then to photosystem I, and ultimately are transferred to NADP+.
The reactions of the Calvin cycle occur in the:
stroma
Photosystems I and II are located in:
the thylakoid membrane
Which of the following are components of both PSI and PSII?
-A reaction center -A light harvesting complex
What are the three phases of the Calvin cycle?
-Carbon fixation -Reduction and carbohydrate production -Regeneration of ribulose bisphosphate
How does photosynthesis benefit organisms that are not plants?
-It produces organic molecules that other organisms use as food. -It produces oxygen that can be used for aerobic respiration.
What three events can happen after an electron absorbs energy and becomes excited?
-The excited electron may be transferred to another molecule. -Energy may be released as light. -Energy may be released as heat.
Arrange the following molecules according to the order of electron flow during photosynthesis. Begin at the TOP with the location where electrons are first excited in noncyclic electron flow. Instructions
1. P80 2. Cytochrome complex 3. Plastocyanin 4. P700 5. NADP+
What is the main product of the Calvin cycle?
Glyceraldehyde-3-phosphate
Living organisms that are not plants depend on photosynthesis because photosynthesis produces: (1) organic molecules such as __________ that can be used for nourishment; and (2) the __________ gas that makes up a large portion of the Earth's atmosphere.
carbohydrates oxygen
Plants appear green because they contain:
chlorophyll