3.3 Photosynthesis Flashcards
What is photosynthesis
It’s the process by which green plants use light energy to make glucose
Chloroplast
Are the site of photosynthesis (where it happens) in a plant cell
Chlorophyll
Is a green pigment found in chloroplasts that trap light energy from the sun
What is needed for photosynthesis
Light and chlorophyll
Word equation
Carbon dioxide + Water = Oxygen + Glucose
Raw materials of the word equation
Carbon dioxide and Water
Products in word equation
Oxygen and Glucose
Two stages of photosynthesis are
Stage one is light reactions
Stage two is carbon fixation
Light reaction
1) Light energy captured by chlorophyll in leaf
2) This is converted to chemical energy in the form of ATP
3) The chemical ATP is used to split water
4) ATP is released from splitting water. This is used in stage two
What happens to oxygen and hydrogen in stage one
Oxygen = diffuses out of the cell
Hydrogen = moves onto stage two
Carbon fixation
1) Hydrogen from stage one combines with carbon dioxide
2) ATP from stage one supplies the energy for the reaction
3) This produces glucose
What is stage two controlled by
Enzymes
What can glucose be used for
- Converted to the storage carbohydrate starch
- Used as a substrate for respiration
- Used structurally to build cell wall ( cellulose )
What is a limiting factor
A limiting factor slows down or stops the rate of photosynthesis because it is in short supply
Name the three limiting factors
- Temperature
- Carbon dioxide concentration
- Light intensity
