Photosynthesis Flashcards
What is photosynthesis:
The process that produces ‘food’ in plants. The ‘food’ it produces is glucose.
How do plants make their own food:
By photosynthesis
Where does photosynthesis take place:
In the leaves of all green plants.
It happens inside the chloroplasts as they contain chlorophyll, which absorbs energy in sunlight and uses it to convert carbon dioxide and water into glucose.
Oxygen is also produced as a by-product.
Word equation for Photosynthesis:
Carbon dioxide + water ~ sunlight ~ glucose + oxygen
Leaves are adapted for efficient photosynthesis:
Are broad, large surface area exposed to light
Contain lots of chlorophyll in chloroplasts to absorb light
Full of little holes called Stomata.
What are stomata’s:
Little holes on a leave that open and close to let glasses like CO2 and O2 in and out.
They also allow water vapour to escape - which is known as transpiration.
What affects photosynthesis:
Light intensity
Concentration of CO2
Temperature
Not enough light slows down the rate of photosynthesis:
Light provides the energy for photosynthesis
When the light level is raised the rate of photosynthesis increases steadily but only up to a certain point
Too little carbon dioxide also slows it down:
Concentration of CO2 will only increase the rate of photosynthesis up to a point.
After this the graph flattens out showing that CO2 is no longer the limiting factor.
The temperature for photosynthesis has to be just right:
Usually the temperature is the limiting factor as it’s too low - the enzymes needed for photosynthesis work more slowly at low temperatures.
If the plant gets too hot, the enzymes it needs for photosynthesis and it’s other reactions will be denatured.
