Photosynthesis

Question 1

Define the term photosynthesis.

Answer 1

Photosynthesis is a series of enzyme controlled reaction which allow green plants to make their own food.

Question 2

State the energy change that occurs during photosynthesis.

Answer 2

In the light dependent stage stage light energy from the sun is trapped by chlorophyll in the Chloroplasts and is converted to chemical energy in the form of ATP.

Question 3

Name the source of energy used by plants to make food.

Answer 3

Light energy from the sun.

Question 4

Name the site of photosynthesis.

Answer 4

Chloroplasts

Question 5

Name the two stages of photosynthesis.

Answer 5

The light dependent stage

Carbon fixation.

Question 6

Name the raw material and pigment required for the first stage of photosynthesis.

Answer 6

Water

Chlorophyll

Question 7

Name all the products made in the first stage of photosynthesis.

Answer 7

Hydrogen
ATP
Oxygen

Question 8

Describe what happens to each of the 3 products produced in the first stage of photosynthesis.

Answer 8

Oxygen diffuses out of the cell
Hydrogen attaches to Hydrogen acceptor molecules to be used in the 2nd stage of photosynthesis

Hydrogen and ATP are used with carbon dioxide to produce sugar.

Question 9

Name the raw material required for the second stage of photosynthesis.

Answer 9

Sugar (glucose)

Question 10

Describe the 3 possible uses for the product of photosynthesis.

Answer 10

Respiration - the sugar is broken down by respiration providing energy for vital processes e.g. Mitosis and reproduction.

Storage - sugar molecules join together to form starch, a storage carbohydrate.

Structural - some sugar molecules join together to form cellulose, a structural carbohydrate found in the cell wall

Question 11

Name the storage carbohydrate produced by plants.

Answer 11

Starch

Question 12

Name the structural carbohydrate produced by plants.

Answer 12

Cellulose

Question 13

Define the term limiting factor.

Answer 13

Limiting factors are environmental factors which can control the rate of photosynthesis.

Question 14

Name 3 possible limiting factors in photosynthesis.

Answer 14

Carbon dioxide concentration
Light intensity
Temperature

Question 15

Describe how increasing light intensity affects the rate of photosynthesis.

Answer 15

As light intensity increases the rate of photosynthesis initially increases. Light intensity is limiting the rate.

The rate of photosynthesis is limited by shortage of another factor

Question 16

Describe how increasing carbon dioxide concentration affects the rate of photosynthesis.

Answer 16

As carbon dioxide concentration increases the rate of photosynthesis initially increases. CO2 Concentration is limiting the rate.

The rate of photosynthesis is limited by shortage of another factor

Question 17

Describe how increasing temperature affects the rate of photosynthesis.

Answer 17

As temperature increases the rate of photosynthesis initially increases.

The rate of photosynthesis reaches its optimum.

The quickly decreases as the enzymes are denatured.