Topic 4 Flashcards
Why is photosynthesis needed
As plants use light for there source of energy
Where does photosynthesis take place
In the leaves (has chlorophyll to absorb light energy)
What’s the word equation for photosynthesis
Carbon dioxide + water -> glucose + oxygen
4 factors that affect rate of photosynthesis
Light intensity
Co2 concentration
Presence of chlorophyll
Temperature
Use of glucose from photosynthesis (respiration)
Release energy in respiration
Takes place in mitochondria
Use of glucose from photosynthesis (starch)
Plant cells respire all the time
So can produce insoluble storage molecules starch
Use of glucose from photosynthesis (cellulose)
Gives plant cel wall strength
Use of glucose from photosynthesis (amino acids)
To synthesise proteins
Absorb nitrate ions from soil
Why do farmers want a higher rate of photosynthesis and how do they do it
Increase yield of crops
More light and heat and co2 (use oil burners to release heat and co2 at same time)
Aerobic respiration equation
Glucose + oxygen -> carbon dioxide + water
Releases great deal of energy
As glucose molecule has been fully oxidised
Anaerobic respiration equation in muscle cells
Glucose -> lactic acid
Releases less energy
As oxidation of glucose is incomplete
Anaerobic respiration equation in plant / yeast cells + why is it useful
Glucose -> ethanol + carbon dioxide
Useful in yeast (fermentation) for alcoholic drinks and bread
When exercising, how does the body provide extra oxygen
Breathing rate and breathing volume increase
So more o2 in bloodstream
So heart rate increases to pump blood
What happens when there isn’t enough oxygen
Anaerobic respiration takes place in muscle cells
Lactic acid causes muscle fatigue (inefficient contraction)
How do we remove lactic acid so we get less muscle fatigue
Transported out of muscle cells by blood
Then to liver where it is converted back to glucose
This requires oxygen
