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