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Biology-Unit 1 > Photosynthesis > Flashcards

Flashcards in Photosynthesis Deck (24):
1

What is photosynthesis?

It is a series of enzyme controlled reactions and occurs in two stages, photolysis and carbon fixation.

2

What are the conditions involved in photosynthesis?

Light and chlorophyll.

3

What are the raw materials involved in photosynthesis?

Carbon dioxide and water.

4

What are the products of photosynthesis?

Glucose and oxygen.

5

What is the word equation for photosynthesis?

Water + CO₂ = Glucose + O₂

6

What is a variegated leaf?

Plants and leaves which do not contain as many chloroplasts which results in the leaf having different colours of green.

7

What is the word equation that shows the energy change?

Light energy = Chemical energy (carbohydrates)

8

Describe photolysis.

The process by which energy from sunlight is used to split water into hydrogen and oxygen. It is dependent on light from the sun.

9

What is the light energy used for?

The light energy is used to make ATP molecules, which provides energy for making glucose.

10

Where does photosynthesis happen?

The chloroplasts.

11

Describe carbon fixation.

Hydrogen from the first stage and carbon dioxide from the air combine to produce glucose. It also requires ATP formed in the first stage to help make glucose.

12

What happens to glucose once it is synthesised? Give 3 fates.

Cellulose which is found in cell walls, stored as starch (in most plant cells but mainly storage cells i.e. potato tubers) and it is used immediately for energy.

13

What can glucose be converted into?

It can be turned into other carbohydrates such as starch and cellulose.

14

What is the structure of a cellulose fibre?

Lined up in parallel chains to form tough fibres.

15

What is the structure of starch?

Coiled shape (tangled).

16

What is a limiting factor?

A factor which limits the rate of photosynthesis.

17

Name 3 limiting factors.

Concentration of CO₂, lack of light (light intensity) or low/high temperatures.

18

How do you overcome these limiting factors?

Light- provide supplementary lighting, CO₂- use heaters that burn paraffin or propane, temperature- use heating.

19

How can photosynthesis be measured?

Number of bubbles per minute/hour, volume of oxygen produced per minute/hour, increase in dry mass (with time), and volume of CO₂ uptake (with time).

20

What is the function of chlorophyll?

Trap light energy for photosynthesis.

21

Describe starch.

Starch is a store of energy and individual glucose molecules can be broken off a large starch molecule when the cell needs energy.

22

What is cellulose?

Cellulose is a tough molecule that is insoluble and not easily broken down. It is used to form cell walls.

23

What can carbohydrates be used for?

Carbohydrates can be used to produce fats and proteins.

24

What is a producer?

A producer is something that produces its own food.