BIOENGERNETICS Flashcards
What are the reactants of photosynthesis?
Carbon dioxide and water.
What are the products of photosynthesis?
Glucose and oxygen.
Where does photosynthesis take place?
In chloroplasts.
How do chloroplasts absorb light?
They contain a green pigment called chlorophyll that absorb light.
Why do only green plants photosynthesise?
Because they have the pigment called chlorophyll.
What is the symbol equation for photosynthesis?
6CO2 + 6H2O → C6H12O6 + 6O2
What are the uses of glucose?
Respiration
Making cellulose
Making amino acids
Storing oils/fats
Stored as starch
Why is glucose made into cellulose?
To make strong cell walls.
How is glucose used for making amino acids?
Glucose combines with nitrate ions from soil to make amino acids which are made into proteins.
How is glucose used for storing fats/oils?
Glucose is turned into lipids (fats/oils) to store seeds.
How is glucose stored as starch?
Glucose is turned into starch and stored in roots, stems and leaves ready for when photosynthesis isn’t happening (e.g. winter). It is insoluble which makes it better for storing glucose.
What will a cell with lots of glucose do?
Draw in lots of water and swell up (that is why glucose is sometimes stored as starch as it is insoluble).
What are the limiting factors of the rate of photosynthesis?
Temperature, carbon dioxide, light and amount of chlorophyll.
How does light affect photosynthesis?
Light provides energy for photosynthesis to occur. If there is not much light then the rate of photosynthesis will decrease.
How does the amount of chlorophyll affect photosynthesis?
Chlorophyll is the green pigment needed for photosynthesis. If there is less chlorophyll then photosynthesis is happening at a slower rate because they cant absorb as much light. The amount of chlorophyll can be affected by disease such as tobacco mosaic virus (lack of nutrients and environmental stress).
Explain how, to a point, light intensity won’t increase photosynthesis.
Beyond a certain point, light intensity will not increase photosynthesis because there is another limiting factor (carbon dioxide or temp).
How does carbon dioxide affect photosynthesis?
Carbon dioxide is a material needed for photosynthesis to occur. If there is not much carbon dioxide then the rate of photosynthesis will decrease.
How does a low temperature affect photosynthesis?
If the temp is too low it can decrease the rate of photosynthesis as the enzymes needed for photosynthesis work more slowly at a lower temp.