Photosynthesis Flashcards
What is photosynthesis?
A two stage process in plants to make sugar from water and carbon dioxide, using light energy.
What is a limiting factor?
A factor or substance that prevents a chemical reaction from happening quicker.
What happens in stage one (light reactions)?
The light energy from the sun is trapped by chlorophyll in the chloroplasts.
Some light energy is converted into chemical energy which is used to generate ATP.
The remains light energy is used to split water into hydrogen and oxygen.
Oxygen diffuses from the cell.
What happens in stage two (carbon fixation)?
The ATP and hydrogen generated from the light reactions and carbon dioxide from the air are combined. They are converted into sugar during a series of enzyme controlled reactions.
What does the plant do with the sugar it makes?
Respiration- The sugar is used by the plant in respiration to produce ATP.
Storage as starch- The sugar is converted into starch. This makes it easier to store the sugar for when the plant needs it later.
Structural as cellulose- The sugar can be converted into cellulose for the plant’s structure. This is used to make new cell walls as the plant grows.
What are the limiting factors?
Temperature
Light intensity
Carbon dioxide concentration
