Photosynthesis
Chloroplasts, Chlorophyll and factors affecting the rate of photosynthesis
- Created by: Laura
- Created on: 14-04-14 13:32
View mindmap
- Chloroplasts, Chlorophyll and factors effecting photosynthesis
- Chloroplasts
- Photosynthesis takes place entirely within chloroplasts
- They have a double membrane like mitochondria but have an extra one called the thylakoid membrane which is folded into vessels enclosing small spaces.
- Chloroplasts contain DNA, tRNA and ribosomes and they often store the products of photosynthesis as starch grains and lipid droplets
- Chlorophyll
- Contain 2 types of chlorophyll; chlorophyll a and b along with a number of light absorbing accessories.
- They absorb light at different pigments so having several allows more of the visible spectrum to be used
- Different plants have different combinations of photosynthetic pigments = different colour leaves
- Chlorophyll is a small molecule arranged in complex proteins called photosystems
- Photosystem one and two absorb different wave lengths of light
- Factors affecting photosynthesis
- Temperature - affects the rate of enzyme reactions so the rate of photosynthesis. Sensitive to temperature with an optimum of about 30-35 degrees Celsius
- Carbon Dioxide concentration - CO2 is the substrate for the enzyme rubisco so higher the CO2 the higher the rate of the Calvin cycle.
- Light intensity - source of energy for the production of ATP and NADPH in the light independent stages, so higher the light intensity the faster the rate of photosynthesi
- Shade plants have a lower optimum intensity where as sun plants have a higher optimum intensity.
- Chloroplasts
Comments
No comments have yet been made