2.9 Photosynthesis Flashcards
Chlorophyll
Photosynthetic pigment that dominates in most plants found in chloroplast, the only structure in a leaf that’s actually green.
Photosynthesis
Converts light energy into chemical energy. Most common chemical energy produced by photosynthesis is glucose
Can also be seen as a series of reactions in which co2 and water and sunlight are fixed into glucose and oxygen is a byproduct
Visible portion of the spectrum
The part of the electromagnetic that plants use also the only part we can see.
The spectrum
Three regions: red end, green middle, blue end. When substances are hit by a colour,
- they can absorb the wavelength, therefore absorb energy
- reflect the wavelength you will see the colour all the others are absorbed
Photosynthesis
Stage 1: Reactions trap light and convert it to ATP
Stage 2: set of reactions ATP is used to help bond co2 and water molecules to create sugar such as glucose
Light dependent reactions
Reactions in 1st stage of photosynthesis where chlorophyll and other pigments absorb light energy and convert it to atp
Photolysis of water
Uses light energy in 1st stage to split the water into hydrogen and oxygen. Oxygen released as a waste product
Light independent reactions
Reactions on stage 2. ATP and hydrogen used as energy to convert water and co2 into useful organic molecules for the plant like glucose.
It takes 6 inorganic co2 for 1 glucose.
Fixation
Conversion of an inorganic form of an element to an organic form which uses atp and hydrogen created in stage 1
Rate of photosynthesis
Highly depends on environmental factors: the intensity of light and air temperature. If it is hot sunny: rste is high, co2 intake and o2 output high. At night rate may drop to 0, may be taken in o2 and give out co2 for cell respiration. Could measure mass to measure rate.
Cell respiration vs photosynthesis
Cell respiration:
- oxygen reactant, co2 product
- rate slow but constant
Photosynthesis:
- oxygen product, co2 reactant
- rate always changing
Effect of changing environment on photosynthesis
- when light intensity increases, rate increases to a certain point then stays the same
- when temp. increases, rate increases, increases molecular collision then enzymes denature it goes all the way down
- increase co2 concentration, increases
Then stays same unless change in temp or light intensity
Photosynthesis and organic molecules
Organic compounds made from inorganic molecules where light energy converted to chemical energy thanks to the pigment chlorophyll
