B8 Photosynthesis Flashcards
(21 cards)
What is photosynthesis?
The process by which plants produce glucose by converting light energy into chemical energy
Where do plants get the light energy needed for photosynthesis from?
The sun
How do plants absorb the sunlight needed for light energy in photosynthesis?
The green chlorophyll in chloroplasts (in the leaves) absorb the light energy
What is the word equation for photosynthesis?
Carbon dioxide + Water —–> Glucose + Oxygen
What is the symbol equation for photosynthesis?
6(CO2) + 6(H2O) —–> C6,H12,O6 + 6(O2)
Why are most leaves very thin and broad?
They are broad to give them a larger surface area for light to land on, they are thin too allow for shorter rates of diffusion
What factors can affect the rate of photosynthesis?
- Light intensity
- Temprature
- Carbon dioxide concentrations
- Chlorophyll levels in the leaf
What happens to the photosynthesis rate as the light intensity increases?
As the light intensity increases the photosynthesis rate also increases (until another factor affects it)
What happens too the photosynthesis rate as the carbon dioxide concentration increases?
As the carbon dioxide concentration increases the photosynthesis rate also increases (until another factor affects it)
What happens too the photosynthesis rate as the temprature increases?
As the temprature increases, the photosynthesis rate increases UNTIL it gets too hot and the enzymes are denatured
What will happen too the amount of photosynthesis that takes place if the amount of chlorophyll in a leaf is limited?
Less photosynthesis will take place
What is the relationship between the light intensity and the distance of the light?
As the distance of the light increases, the intensity of the light decreases (inverse square law)
What is the inverse square law in light intensity?
The light intensity is inversely proportional to the square of the distance from the light source to the object
Light intensity = 1 / Distance^2
Why do plants have to convert glucose into starch?
Plants cannot store glucose, so they convert it into starch. Starch is insoluble so it can be stored easily.
How do you test for starch?
Using an iodine test, the substance turns blue/black if starch is present
What is the symbol equation for glucose?
C6,H12,O6
What is the substance that absorbs light energy in the leaves called?
Chlorophyll
Is photosynthesis an endothermic or exothermic reaction?
Endothermic
What are the 3 main uses of glucose?
- Cellular respiration
- Make cellulose
- Make starch
Why is starch a useful long term storage molecule?
- It is compact
- It is insoluble
- It can easily be broken down when needed
What are 2 leaf adaptations that maximise the amount of light energy absorbed?
- Broad leaves (larger surface area)
- Thin leaves (shorter diffusion rates)
