Photosynthesis Chapter 10 Flashcards

Questions and Answers

A photosystem consists of which of the following structures? (Select all that apply)

Primary electron acceptor (correct)

Light harvesting complexes (correct)

Chlorophyll molecules (correct)

Reaction-Centre Complex (correct)

The light reactions of photosynthesis supply the Calvin Cycle with ___________.

ATP and NADPH.

Why do the reactions of the Calvin Cycle usually not occur at night?

The Calvin Cycle requires products only produced when the photosystems are illuminated.

In photosynthesis, plants use carbon from __________ to make sugar and other organic molecules.

Carbon Dioxide. Signup and view all the answers

What property of the pigment chlorophyll makes it appear green?

Chlorophyll absorbs all of the visible spectrum of light except green, which it reflects. Signup and view all the answers

Which process occurs during the second phase, the reduction phase, of the Calvin cycle?

G3P Production. Signup and view all the answers

How does carbon dioxide enter the leaf?

Through the stomata. Signup and view all the answers

The light reactions of photosynthesis occur in the __________.

Thylakoids. Signup and view all the answers

During which process is molecular oxygen produced in photosynthesis?

The light reactions by linear electron flow. Signup and view all the answers

The energy used to produce ATP in the light reactions of photosynthesis comes from ____________.

The movement of H+ through a membrane. Signup and view all the answers

The source of the oxygen produced by photosynthesis has been identified through experiments using radioactive tracers. The oxygen comes from __________.

Water. Signup and view all the answers

Where does the Calvin Cycle of photosynthesis occur?

Stroma. Signup and view all the answers

Why could the Calvin Cycle not occur without the light reactions?

ATP and NADPH produced in the light reactions provide the energy for the production of sugars in the Calvin Cycle. Signup and view all the answers

Where do the electrons entering photosystem II come from?

Water. Signup and view all the answers

The light reactions of photosynthesis use chemiosmosis to produce ATP that will be used in the Calvin Cycle. Across which structure(s) is the electrochemical gradient formed?

Thylakoid membrane. Signup and view all the answers

Why are most autotrophs referred to as the producers of the biosphere?

They are the ultimate sources of organic compounds for all nonautotrophic organisms. Signup and view all the answers

What difference in carbon fixation exists between C3 and C4 plants?

The first product of carbon fixation in C4 plants is a four-carbon compound instead of a three-carbon compound. Signup and view all the answers

What energy source did a philodendron use while in total darkness?

It stored energy in the form of sugars or starch. Signup and view all the answers

Which of the following occurs during the Calvin Cycle?

CO2 is reduced. Signup and view all the answers

Chlorophyll molecules are in which part of the chloroplast?

Thylakoid membranes. Signup and view all the answers

G3P is used in which of the following processes? (Select all that apply)

Production of cellulose Signup and view all the answers

In the light reactions of photosynthesis, ATP is produced by photophosphorylation. Which process is most similar to photophosphorylation?

Oxidative phosphorylation in cellular respiration. Signup and view all the answers

Both mitochondria and chloroplasts _______________.

Use chemiosmosis to produce ATP. Signup and view all the answers

The light reactions of photosynthesis generate high-energy electrons, which end up in . They also produce and __.

NADPH Signup and view all the answers

During the Calvin Cycle, what happens during the carbon fixation phase?

The Calvin Cycle incorporates each CO2 molecule, one at a time, by attaching it to a five-carbon sugar named ribulose bisphosphate. Signup and view all the answers

When chloroplast pigments absorb light, ____________.

Their electrons become excited. Signup and view all the answers

What is the most important role of pigments in photosynthesis?

To capture light energy. Signup and view all the answers

Carbon dioxide and oxygen enter and exit a leaf by diffusion. Which structure(s) on a leaf allow(s) this process to happen?

Stomata. Signup and view all the answers

In photosynthesis, what molecule is oxidised and what molecule is reduced?

Water is oxidised. Carbon Dioxide is reduced. Signup and view all the answers

Which of the following statements correctly distinguishes between autotrophs and heterotrophs?

Autotrophs, but not heterotrophs, can nourish themselves beginning with CO2 and other nutrients that are organic. Signup and view all the answers

Study Notes

Photosystem Structure

A photosystem consists of a Reaction-Centre Complex, Chlorophyll molecules, Light harvesting complexes, and a Primary electron acceptor.

Light Reactions and the Calvin Cycle

Light reactions produce ATP and NADPH, which supply the Calvin Cycle.
The Calvin Cycle requires ATP and NADPH generated by light reactions and typically does not occur at night due to dependency on light-induced products.

Carbon Source for Photosynthesis

Plants utilize Carbon Dioxide to synthesize sugar and organic molecules.

Chlorophyll Properties

Chlorophyll appears green because it reflects green light while absorbing other wavelengths from the visible spectrum.

Calvin Cycle Phases

G3P is produced during the reduction phase of the Calvin Cycle.

Carbon Dioxide Entry

Carbon dioxide enters leaves through stomata.

Location of Light Reactions

Light reactions occur in the thylakoids of chloroplasts.

Oxygen Production

Molecular oxygen is produced during the light reactions via linear electron flow.

ATP Production Mechanism

ATP in light reactions is produced through the movement of H+ ions across membranes.

Source of Oxygen

The oxygen generated in photosynthesis originates from water.

Calvin Cycle Occurrence

The Calvin Cycle takes place in the stroma of chloroplasts.

Dependency of Calvin Cycle on Light Reactions

The Calvin Cycle cannot occur without light reactions, as ATP and NADPH generated by the latter are essential for sugar production.

Electrons in Photosystem II

Electrons entering photosystem II are sourced from water.

Chemiosmosis in ATP Production

The thylakoid membrane forms an electrochemical gradient pivotal for chemiosmosis during ATP production.

Autotrophs as Producers

Autotrophs are referred to as producers because they are the primary source of organic compounds for non-autotrophic organisms.

Carbon Fixation in C3 vs. C4 Plants

In C4 plants, the first product of carbon fixation is a four-carbon compound, in contrast to the three-carbon compound in C3 plants.

Energy Source in Darkness

A philodendron can survive in darkness by utilizing stored sugars or starch for energy.

Carbon Fixation in the Calvin Cycle

During carbon fixation, CO2 is incorporated one molecule at a time to ribulose bisphosphate.

Excitation of Electrons in Pigments

When chloroplast pigments absorb light, their electrons become excited.

Role of Pigments

The primary role of pigments in photosynthesis is to capture light energy.

Diffusion of Gases

Stomata enable the diffusion of carbon dioxide and oxygen into and out of leaves.

Redox Processes in Photosynthesis

In photosynthesis, water is oxidized and carbon dioxide is reduced.

Distinction Between Autotrophs and Heterotrophs

Autotrophs can nourish themselves starting from CO2 and inorganic nutrients, unlike heterotrophs.

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Description

Test your knowledge of the structures involved in photosystems and the process of photosynthesis with these flashcards. This quiz covers crucial concepts, including the light reactions and the Calvin Cycle. Perfect for students studying botany or biology at the chapter 10 level.