B8 photosynthesis

Question 1

Photosynthesis

Answer 1

Photosynthesis - The process where plants make their own food (glucose) using light energy.
.happens in the chloroplasts of plant cells (contains chlorphyll)

Question 2

Photosynthesis Equation & Symbol Equation

Answer 2

Carbon Dioxide + Water - Glucose + Oxygen (light energy)

6CO2 + 6H20 - C6 H12 06 + 602

Question 3

Where photosynthesis happens

Answer 3

.in the leaves (main site
.in chloroplasts (contain green chlorophyll to Absorb light)

Photosynthesis is an Endothermic Reaction
.takes in energy from the surroundings (sunlight)
.stores energy in glucose molecules.

Question 4

What is glucose used for ?

Answer 4

Respiration - Releases energy for plant cells
Making starch - Stored for later (especially at night)
Making amino acids- For protein (needs nitrate ions from soil)
Making fats/oils - stored in seeds and for energy.

Question 5

Required Practical

Answer 5

Method : Using Pondweed ( e.g Elodea) to measure the rate of photosynthesis
By counting bubbles of oxygen.

Variable : Change light intensity by moving lamp/closer or further.

Control Variable : Same Temperature, same amount of pondweed, Same time etc.

Question 6

Limiting factors of photosynthesis

Answer 6

Light intensity: More light = more energy for reaction
Carbon Dioxide Concentration = CO2 is a raw material
Temperature : Affects enzyme activity (too hot = enzymes denature)
Chlorophyll - less chlorophyll= less light absorbed

Light Intensity & Distance
Light intensity x 1 distance 2

Question 7

Greenhouse Conditions for Farming

Answer 7

Light : Artificial lighting .Water Irrigation
.Temperature : heating
.CO2: Use paraffin heaters
Glucose - Lactic Acid (+energy)

Anaerobic in Yeast
Glucose - Ethanol + Carbon Dioxide

Question 9

Whats Respiration used for “