8. Photosynthesis

Question 1

What controls the reactions in photosynthesis?

Answer 1

Enzymes.

Question 2

What does photosynthesis allow plants to do?

Answer 2

Make their own food.

Question 3

What is light energy trapped by?

Answer 3

Chlorophyll.

Question 4

Where is chlorophyll found?

Answer 4

Chloroplasts.

Question 5

What compound contains the chemical elements carbon (C), Hydrogen (H) and oxygen (O) combined using energy?

Answer 5

Carbohydrate.

Question 6

What raw materials does the production of carbohydrate food require to be available to supply the necessary chemicals?

Answer 6

Water and carbon dioxide.

Question 7

What are the reactants of photosynthesis?

Answer 7

Light energy, water, carbon dioxide and chlorophyll.

Question 8

What are the products of photosynthesis?

Answer 8

Glucose, oxygen and water.

Question 9

During photosynthesis molecules of what combine with hydrogen from water?

Answer 9

Carbon dioxide.

Question 10

What does the reaction of photosynthesis require the presence of to form sugar?

Answer 10

Chlorophyll and light energy.

Question 11

What is the food product of photosynthesis?

Answer 11

Sugar.

Question 12

What are the two stages of photosynthesis?

Answer 12

The light-dependent stage (consisting of several light dependent reactions) and the temperature-dependent stage (carbon fixation).

Question 13

During the series of light reactions light energy is trapped by Chlorophyll and converted to what?

Answer 13

Chemical energy in the form of energy- rich ATP.

Question 14

What is the ATP regenerated from?

Answer 14

ADP + Pi.

Question 15

Some energy is also used during the light dependent stage to split what?

Answer 15

Water into hydrogen and oxygen.

Question 16

What happens as a result of the light dependent stage?

Answer 16

Oxygen is released as a by-product and diffuses out of the plant and the hydrogen and ATP are formed and used during the carbon fixation.

Question 17

Where does carbon fixation occur within the cell?

Answer 17

Chloroplasts.

Question 18

What does carbon fixation consist of?

Answer 18

Several enzyme controlled reactions in the form of a cycle.

Question 19

During carbon fixation, what combines with what to form sugar?

Answer 19

Carbon (from carbon dioxide) with Hydrogen from the light-dependent stage.

Question 20

What supplies the energy needed to drive the process of carbon fixation?

Answer 20

ATP.

Question 21

Sugar from photosynthesis is broken down by what to supply the plant with energy?

Answer 21

Respiration.

Question 22

What activities is the energy that the sugar from photosynthesis supplies the plants with used for?

Answer 22

Energy requiring processes such as cell division and reproduction.

Question 23

Some of the remaining glucose molecules become linked into long chains and packed together to form what?

Answer 23

Starch grains.

Question 24

Where are starch grains found?

Answer 24

The cells cytoplasm.

Question 25

What is the purpose of starch grains in a plant?

Answer 25

It is the plants food storage and can be converted back to sugar when energy is required.

Question 26

Other glucose molecules are built into long chains of what?

Answer 26

Cellulose.

Question 27

What is the purpose of cellulose in a plant?

Answer 27

They are gathered together to form the fibres needed to build cell walls.

Question 28

What type of carbohydrate is a starch grain called?

Answer 28

A storage carbohydrate.

Question 29

What type of carbohydrate is cellulose called?

Answer 29

A structural carbohydrate.

Question 30

What non-carbohydrates can carbohydrates, produced during photosynthesis, also be converted to?

Answer 30

Fats and proteins.

Question 31

What is additionally required to make proteins from carbohydrates?

Answer 31

Chemicals such as nitrate. These chemicals are absorbed from the soil solution by the plants root hairs.

Question 32

What factors can effect photosynthetic rate?

Answer 32

Light intensity, carbon dioxide concentration, water availability and temperature.