Lesson 5.1 - Photosynthesis: An Introduction

Question 1

Define Photoautotroph

Answer 1

An organism that makes its own food using energy from the Sun.

Question 2

What is an organism that makes its own food using energy from the Sun known as?

Answer 2

Photoautotroph

Question 3

Define Light-Dependent Reactions

Answer 3

The first stage of photosynthesis, during which water molecules are split as light energy is absorbed and transformed into chemical energy in ATP and NADPH.

Question 4

What is the first stage of photosynthesis, during which water molecules are split as light energy is absorbed and transformed into chemical energy in ATP and NADPH known as?

Answer 4

Light-Dependent Reactions

Question 5

Define Calvin Cycle

Answer 5

The second stage of the photosynthesis process that uses ATP and NADPH to conver CO₂​ into sugars.

Question 6

What is the second stage of the photosynthesis process that uses ATP and NADPH to conver CO2​ into sugars known as?

Answer 6

Calvin Cycle

Question 7

Define Primary Electron Acceptor

Answer 7

A molecule capable of accepting electrons and becoming reduced during photosynthesis.

Question 8

What is a molecule capable of accepting electrons and becoming reduced during photosynthesis known as?

Answer 8

Primary Electron Acceptor

Question 9

Define Antenna Complex

Answer 9

A cluster of light-absorbing pigments embedded in the thylakoid membrane able to capture and transfer energy to special chlorophyll a molecules in the reaction centre.

Question 10

What is a cluster of light-absorbing pigments embedded in the thylakoid membrane able to capture and transfer energy to special chlorophyll a​ molecules in the reaction centre known as?

Answer 10

Antenna Complex

Question 11

Define Reaction Centre

Answer 11

A complex of proteins and pigments that contain the primary electron acceptor.

Question 12

What is a complex of proteins and pigments that contain the primary electron acceptor known as?

Answer 12

Reaction Centre

Question 13

Define Absorption Spectrum

Answer 13

A plot of the amount of light energy of various wavelengths that a substance absorbs.

Question 14

What is a plot of the amount of light energy of various wavelengths that a substance absorbs known as?

Answer 14

Absorption Spectrum

Question 15

Define Action Spectrum

Answer 15

A plot of the effectiveness of light energy of different wavelengths in driving a chemical process.

Question 16

A plot of the effectiveness of light energy of different wavelengths in driving a chemical process known as?

Answer 16

Action Spectrum

Question 17

Define Photosystem I

Answer 17

A collection of pigment proteins that includes chlorophyll a and absorbs light at the 700 nm wavelength.

Question 18

What is a collection of pigment proteins that includes chlorophyll a and absorbs light at the 700 nm wavelength known as?

Answer 18

Photosystem I

Question 19

Define Photosystem II

Answer 19

A collection of pigment proteins that includes chlorophyll a and absorbs light at the 680 nm wavelength.

Question 20

What is a collection of pigment proteins that includes chlorophyll a and absorbs light at the 680 nm wavelength known as?

Answer 20

Photosystem II

Question 21

Producers use _____ to convert light energy into chemical energy, which is then stored and used to assemble energy-rich organic molecules that are used by producers and consumers.

Answer 21

Producers use photosynthesis to convert light energy into chemical energy, which is then stored and used to assemble energy-rich organic molecules that are used by producers and consumers.

Question 22

Photosynthesis has two stages—the _____-dependent reactions, and the _____-independent reactions (the _____ cycle).

Answer 22

Photosynthesis has two stages—the light-dependent reactions, and the light-independent reactions (the Calvin cycle).

Question 23

The light-dependent reactions take place in the _____ membranes of the chloroplasts. Energy captured during the light-dependent reactions is used to synthesis _____ and _____.

Answer 23

The light-dependent reactions take place in the thylakoid membranes of the chloroplasts. Energy captured during the light-dependent reactions is used to synthesis NADPH and ATP.

Question 24

The Calvin cycle takes place in the _____ of the chloroplasts. It uses NADPH and ATP to convert _____ into simple carbohydrates.

Answer 24

The Calvin cycle takes place in the stroma of the chloroplasts. It uses NADPH and ATP to convert carbon dioxide into simple carbohydrates.

Question 25

Chlorophylls, carotenoids, and other pigments absorb _____ energy during photosynthesis. Different pigments absorb light of different \_\_\_\_\_, as shown by their absorption spectra. Light that is not absorbed is reflected. This reflected light gives pigments their \_\_\_\_\_.

Answer 25

Chlorophylls, carotenoids, and other pigments absorb **light** energy during photosynthesis. Different pigments absorb light of different **wavelengths**, as shown by their absorption spectra. Light that is not absorbed is reflected. This reflected light gives pigments their **colour**.

Question 26

The action spectrum of photosynthesis in green plants is highest in the _____ and _____ regions of the spectrum.

Answer 26

The action spectrum of photosynthesis in green plants is highest in the **red** and **blue** regions of the spectrum.

Question 27

Pigments, including chlorophylls and carotenoids, are organized into two type of photosystems: _____ and \_\_\_\_\_. Each photosystem contains a reaction centre surrounded by an _____ that helps capture photons of light energy and energize electrons.

Answer 27

Pigments, including chlorophylls and carotenoids, are organized into two type of photosystems: **photosystem I** and **photosystem II**. Each photosystem contains a reaction centre surrounded by an **antenna complex** that helps capture photons of light energy and energize electrons.