Chapter 8 Photosynthesis

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A pigment is a molecule that can

Absorb light

What molecule is reduced in the Calvin cycle?

CO2

Sunlight provides the _____ that is necessary for the synthesis of glucose from carbon dioxide

Energy

True or False: Glucose is the primary output of the Calvin cycle.

False

What molecule is produced by photosystem II?

Oxygen

In hot dry conditions, rubisco can attach O2 to RuBP in a process called _______, which ultimately produces CO2

Photorespiration

The process by which plants capture light energy and use it to synthesize glucose and other organic molecules is called

Photosynthesis

During photosynthesis, NADPH is synthesized by

Photosystem I

A molecule that can absorb light energy is called a(n)

Pigment

The light-harvesting complex is composed of several dozen _______ molecules that are anchored to transmembrane proteins.

Pigment

What happens during photosynthesis?

Plants capture energy from sunlight and use it to synthesize organic molecules

Which of the following are products of the light reactions of photosynthesis that are used as reactants in the Calvin cycle.

ATP, NADPH

Which of the following are major chemical products of the light reactions of photosynthesis?

ATP, Oxygen, NADPH

What happens when a photon of light is absorbed by a pigment molecule?

An electron is boosted to a higher level

Which of the following summarizes the events of the first phase of the Calvin cycle?

Atmospheric carbon dioxide is fixed into a five carbon sugar.

A(n) _____ can synthesize organic molecules from inorganic molecules, while a(n) ____ must consume food to obtain organic molecules

Autotroph, heterotroph

Why is light considered a form of electromagnetic radiation?

Because it consists of both electric and magnetic energy

In some plants, carbon fixation yields a four-carbon molecule instead of G3P as the first product. Such plants are known as ______ plants

C4

________ plants avoid water loss by closing their stomata during the day and opening them at night

CAM

How do CAM plants avoid water loss?

CAM plants close their stomata during the day and open them at night.

In the first phase of the _______, atmospheric carbon dioxide is fixed into a five carbon sugar.

Calvin cycle.

The end product of phase 2 of the Calvin cycle is G3P. This molecule is used to synthesize _______ and to regenerate the starting material _______ bisphosphate.

Carbohydrate, RuBP

What are the three phases of the Calvin cycle?

Carbon fixation, reduction and carbohydrate production, regeneration of ribulose bisphosphate

Sequence the phases of the Calvin cycle from first (on top) to last:

Carbon fixation, reduction and carbohydrate production, regeneration of ribulose bisphosphate.

In the light reactions, ATP is generated via

Chemiosmosis

Similar to ATP synthesis in mitochondria, ATP synthesis in chloroplasts is achieved by a(n) _____ mechanism called phosphorylation

Chemiosmosis

Green plants utilize _____ a and b to absorb light energy in photosynthesis.

Chlorophyll

Plants appear green because they contaim

Chlorophyll

The green color of plants is due primarily to the absorptive properties of the pigment ____ found in the chloroplasts

Chlorophyll

In photosynthesis, light energy is converted to _____ energy, which in turn is converted to _____ energy in a sugar molecule.

Electrochemical, chemical

Light is a type of _____ radiation because it consists of energy in the form of electric and magnetic fields.

Electromagnetic

When a pigment molecule absorbs a photon of light, a(n) _______ is boosted to a higher energy level.

Electron

After a pair of ______ reach QB, each enters a transport chain in the thylakoid membrane.

Electrons

NADP+ reductase transfers two _____ and one _____ to NADP+ to generate NADPH

Electrons, H+

During resonance energy transfer, what is transferred from one molecule to another?

Energy

The incorporation of carbon from CO2 in the atmosphere into an organic molecule called carbon ________

Fixation

After ______ molecules are made, they may be linked together in a polysaccharide called starch.

Glucose

In plants, which of the following is polymerized to form starch?

Glucose

Which of the following is the primary output of the Calvin cycle?

Glyceraldehyde-3-phosphate

The energy released as electrons pass from an electron carrier to another in the electron transport chain between photosystem II and photosystem I is used to

Pump H+, establish an electrochemical gradient

In the Calvin cycle, CO2 is

Reduced

The energy of an excited electron can be transferred from one pigment molecule to another via ______ energy transfer.

Resonance

In the last phase of the Calvin cycle, what molecule is regenerated so that the next cycle can occur?

Ribulose bisphosphate

What happens during photorespiration?

Rubisco attaches O2 to RuBP, and CO2 is produced.

The reactions of the Calvin cycle occur in the

Stroma

The energy required for the synthesis of glucose from carbon dioxide ultimately comes from

Sunlight

Photosystems I and II are located in

The thylakoid membrane

Homologous genes are similar to one another because

They are derived from the same ancestral gene

The ____ membrane of the chloroplast contains two independent, light capturing complexes of proteins and pigments called photosystems I and II

Thylakoid

Which of the following is the purpose of phase 3 of the Calvin cycle?

To create a new 5-carbon sugar for the "next" Calvin cycle.

The electrons that exit PSII are replenished by electrons from oxidized _____ which yields oxygen gas that can be used by plant cells or released to the environment.

Water

Which of the following conditions affect the way the Calvin cycle operates in photosynthetic organisms?

Water availability, light intensity, temperature

The Calvin cycle is affect by certain environmental conditions, including light intensity, _______ availability, and _______.

Water, temeprature

The model for photosynthesis that incorporates two photo activation events and shows the series of energy changes during the light reactions of photosynthesis is called the _______ scheme.

Z

What happens to a pair of electrons after it reaches QB?

It enters an electron transport chain in the thylakoid membrane

Several dozen pigment molecules anchored to transmembrane proteins make up the ______ -harvesting complex of a photosystem.

Light

______ excite(s) electrons in pigment molecules in photosystems I and II.

Light

What energy conversion occurs during photosynthesis?

Light energy is converted to electrochemical energy, which is converted to chemical energy

Which of the following are components of both PSI and PSII?

A reaction center, a light harvesting complex

Where do the light reactions occur?

In the thylakoids membrane

What is carbon fixation?

Incorporation of carbon into an organic molecule that is not a gas

A key role of PSI is to produce high-energy electrons that are used to make

NADPH

Which of the following are products of light reactions that are used by the Calvin cycle to make carbohydrates?

NADPH and ATP

The flow of electrons from PSII to PSI is called _______ electron flow because the electrons move linearly from PSII to PSI.

Noncyclic

The products of the light reactions of photosynthesis are

O2, NADPH, and ATP

In C4 plants, the first product of carbon fixation is

A four-carbon molecule

According to the Z scheme, how many photo activation events occur during photosynthesis?

2

Match each term with the correct description

Heterotroph- must consume food to obtain organic molecules, Autotroph- produces organic molecules from inorganic molecules Photoautotroph- uses light energy to drive the synthesis of organic molecules from inorganic molecules

_______ genes are similar to each other because they are derived from the same ancestral gene.

Homologous

The energy that is released as electrons pass from one electron carrier to the next is used to pump _______ ions into the thylakoid lumen

Hydrogen

What is the function of chlorophyll during photosynthesis?

It absorbs light energy

How does an electron present in the pigment of the light-harvesting complexes become excited?

Light excites an electron in a pigment found in the light-harvesting complexes of the photosystems.

PSI and PSII have two main components: a(n) ______ harvesting complex and a(n) _____ center.

Light, reaction

The flow of electrons from PSII to PSI is considered to be

Linear electron flow

The G3P produced at the end of the second phase of the Calvin cycle is directly used for which of the following?

Make glucose or other carbohydrates, regenerate ribulose bisphosphate

How is NADPH formed in PSI?

NADP+ reductase adds two electrons and a H+ to NADP+


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