- Created by: R214116
- Created on: 18-10-18 20:06
What is photosynthesis?
- process that produces glucose for in plants and algae.
- happens inside chloroplasts
The raw materials for photosynthesis:
- sunlight beats down on the leaf and is absorbed by green chlorophyll in chloroplasts and provides energy for the reaction
- water reaches the cells via xylem
- CO2 diffuses into the leaf
Equation for photosynthesis:
- carbon dioxide + water >>>>light energy>>>> glucose + oxygen
6CO2 + 6H2O >>>> light energy>>>> C6H12O6 +6O2
Plants are made of organs like stems, roots and leaves.
These organs are made of tissues.
Leaves are made of:
- mesophyll tissue- where most photosynthesis happens
- xylem and phloem - transport water, mineral ions and sucrose around the plant
- epidermal tissue - covers the whole plant
Rate of Photosynthesis - Light
Not enough light slows the rate of photosynthesis.
- light provides energy needed for photosynthesis
- as light level increases, the rate of photosynthesis increases but only until a certain point
- at this point it is no longer the mimicking factor
In a lab
- in a lab, you can change light intensity by moving a lamp closer and further away from a plant.
- you should measure light intensity using a light meter
Rate of Photosynthesis - Carbon Dioxide
Too little carbon dioxide slows the rate of photosynthesis
- carbon dioxide is a raw material for photosynthesis
- as carbon dioxide levels increase, the rate of photosynthesis increases up until a certain point
- after this, carbon dioxide is no longer the limiting factor
In a lab
- carbon dioxide levels can be increased by dissolving different amounts of sodium hydrogencarbonate in the water.
Rate of Photosynthesis - Temperature
The temperature must be just right
- temperature can be the limiting factor because it's too low - the enzymes needed for photosynthesis work slower in the cold
- if the temperature is too high, enzymes will become denatured (45 degrees)
In a lab
- temperature levels can be controlled using a water bath