Photosynthesis Flashcards
what is photosynthesis? what is needed?
Plants trap energy from sunlight and convert it into chemical energy which they store in the bonds of glucose molecules. Light, water and carbon dioxide are needed
Where does photosynthesis take place? Which part of the chloroplast is involved? What does the inner membrane surround? What does this fluid contain. Where is chlorophyll made?
Photosynthesis happens in chloroplasts. Chloroplasts have stacks of flattened membranes called grana. The grana contain chlorophyll where the light reactions occur. Inner membrane surrounds an area filled with a liquid called stroma
Stroma has enzymes, DNA and ribosomes
The grana consist of stacks of disc-shaped structures called thylakoids where chlorophyll is made
what is the first stage of photosynthesis? What does this occur? What happens during this stage?
Light-dependent stage
Takes place in the thylakoid
Light energy is absorbed by chlorophyll and is used to make ATP
During this process, photolysis occurs where water is broken down into oxygen gas and hydrogen ions (H+)
Oxygen is released
what is the formula for the light-dependent stage?
Light energy
Water ——————> hydrogen gas + oxygen + ATP
Chlorophyll
what is the second stage of photosynthesis? where does it take place? What happens?
Light-independent stage (Calvin Cycle)
Takes place in the stroma
No solar energy is required. ATP made in light dependent stage is used
Carbon dioxide and hydrogen ions are combined to make glucose and water
what is the formula for the second stage?
Hydrogen ions + ATP + carbon dioxide ——> glucose + water + ATP
what is the formula for photosynthesis?
Water + carbon dioxide ———> glucose + oxygen + water
12H2O + 6CO2 ————> C6H12O6 + 6O2 + 6H2O
how does light intensity affect the rate of photosynthesis?
Low light intensity, light dependent reactions cannot occur
As light increases, so does rate of photosynthesis, to a certain point
how does carbon dioxide concentration affect the rate of photosynthesis?
Carbon dioxide is an input of photosynthesis
Will not occur if carbon dioxide is not present
Increase in it, then increase in photosynthesis until a certain point
how does temperature affect the rate of photosynthesis?
Light dependent and light independent reactions are catalysed by enzymes
Enzyme activity is sped up as temperature rises
Too hot, enzymes no longer work (become denatured or fall apart)
There is an optimum temperature for photosynthesis to occur
what is a limiting factor?
The factor present in the smallest amount is the limiting factor eg. Not enough light to preform photosynthesis despite their being enough carbon dioxide
what is the light condensation point?
The light condensation point is the level of light at which the rates of photosynthesis and cellular respiration are the same and their is not net exchange of oxygen.
