4.4.1 photosynthesis Flashcards
What is the main limiting factor of photosnthesis during winter.
Temperature
What is the equation for photosynthesis?

How do plants make Amino acids?
They combine glucose with nitrates.
When using a lamp to look at how light intensity affects rate of photosynthesis, how can we increase the light intensity?
Move the lamp closer.
What is the symbol for magnesium ions?
Mg2+
Identify the limiting factor/s at point B
Explain how you know.

CO2 conc/Temperature/Chlorophyll/Water
Because when light intensity increases past this point rate of photosynthesis does not - so must be one of the other factors.

Identify the limiting factor at point A.
Explain how you know.

CO2 concentration.
because as CO2 concentration increases so does the rate of photosynthesis

What is the symbol for nitrates?
NO3-
What is meant by a limiting factor of photosynthesis?
Something that slows down the amount of photosynthesis that a plant can do.
Which type of energy allows carbon dioxide and water to be converted into glucose and oxygen?
Light energy
Where do plants get nitrates?
From the soil
Why do plants need magnesium ions from soil?
to make chlorophyll
What is the symbol equation for photosynthesis?

What is the main limiting factor of photosynthesis on a Summer day? Explain your answer.
CO2 concentration.
Because it is generally warmer in Summer.
Because there is a higher light intensity in Summer.
Atmospheric CO2 is low (0.03%).
What 5 things do plants use glucose for?
- Oils - energy store
- Starch - energy store
- Cellulose - for cell walls
- Amino acids - for growth and repair
- Respiration - for energy
OSCAR (wil help you remember!)
A plant tha is lacking magnesium will show what symptoms?
Yellow leaves as less chlorophyll.
Poor growth as less photosynthesis happening.
What is the main limiting factor of photosynthesis at night time?
The amount of light
Starch is insoluble in the cytoplasm of plant cells. Why is this a useful property?
It does not increase the concentration of cytoplasm.
So water does not move into the cell via osmosis which would cause the cell to swell up.
What are the limiting factors of photosynthesis?
- Light
- CO2 concentration.
- Temperature
- Amount of chlorophyll
- Water availability
How can we calculate the light intensity coming from a lamp that is reaching a plant?
The Inverse Square Law
Light intensity = 1 ÷ Distance of plant from lamp²