2.18-2.70 Plant nutrition

Question 1

Define photosynthesis

Answer 1

• Produces glucose for plants
• Happens in the leaves in the chloroplasts (these contain a pigment called chlorophyll which absorbs sunlight and uses its energy to convert carbon dioxide and water into glucose
• Converts light energy to chemical energy, which is stored in the glucose –> chemical energy released when glucose is broken down during respiration

Question 2

What is the word equation and symbol equation for photosynthesis?

Answer 2

carbon dioxide + water –> glucose + oxygen

6CO2 + 6H2O –> C6H12O6 + 6O2

Question 3

What do plants use glucose for?

Answer 3

• Respiration
• Stored as starch
• Turned into cellulose
• To make fats and oils

Question 4

What does photoautotrophic mean?

Answer 4

Generate their own “food” using energy from the sun

Question 5

What are the limiting factors of the rate of photosynthesis?

Answer 5

Stops photosynthesis from happening any faster

• Light intensity
• CO2 concentration
• Temperature

Question 6

How does light intensity affect the rate of photosynthesis?

Answer 6

Without enough light, a plant cannot photosynthesise very quickly, even if water and carbon dioxide are in excess
Increase in light intensity = Increase in rate
Second factor limiting is carbon dioxide