Photosynthesis Flashcards
(24 cards)
.Draw the structure of a chloroplast?
What are the photosynthetic pigments?
chlorophyll a, chlorophyll b and carotene
What is the role of a photosynthetic pigment?
They absorb the light energy needed for photosynthesis.
What is a photosystem?
This is a protein attached to a pigment.
What are the two photosystems in the thylakoid membrane? What are the wavelengths they absorb?
- PSI- 700nm
- PSII- 680nm
What is reduction in terms of electrons, hydrogen and oxygen?
Reduction is the gain of electrons and hydrogen. It is also the loss of oxygen.
What is oxidation in terms of electrons, hydrogen and oxygen?
Oxidation is the loss of electrons and hydrogen. It is also the gain of oxygen.
What are coenzymes?
Substances that aid the function of an enzyme.
What is the coenzyme involved in photosynthesis?
NADP.
Where does the light dependent reaction take place?
thylakoid membranes
What is an electron transport chain?
A chain of proteins that allows electrons to flow through it.
Describe the stages of the light dependent reaction?
What does cyclic photophosphorylation stand for?
ATP is only made in the PSI and the electrons from the chlorophyll aren’t passed onto the NADP, but are brought back to the PSI via the electron transport chain.
Where does the Calvin cycle take place?
the stroma of the chloroplasts
Describe the stages of the light-independent reaction.
What are carbohydrates made up of?
Hexose sugars are made up of two TP molecules joined together. Larger carbohydrates are made up of many hexose sugars joined together.
What are proteins made up of?
The amino acids are made from GP.
What are lipids made up of?
The glycerol is made up of TP. The fatty acids are made up of GP.
What are the optimum conditions needed for photosynthesis?
- High light intensity of a certain wavelength.
- Temperatures around 25 degrees
- High carbon dioxide concentration.
- Constant supply of water.
Why do plants need high light intensity at certain wavelengths?
The higher the light intensity the more energy it provides for photosynthesis. It needs to be at certain wavelengths because the photosynthetic pigments only absorb red and blue light.
Why do plants need temperatures of around 25 degrees for photosynthesis?
If the temperature becomes too low the enzymes, ATP synthase and rubisco, become inactive. If the temperature is too high the enzymes denature and the stomata close meaning carbon dioxide no longer enters the plant and photosynthesis slows down.
Why do plants need high carbon dioxide concentrations for photosynthesis?
The higher the concentration of carbon dioxide the higher the rate of photosynthesis.
Why do plants need a constant supply of water?
The higher the amount of water they have the higher the rate of photosynthesis. However, if there is too much the soil becomes waterlogged and that stops the roots from taking up important mineral ions.
What are the limiting factors for photosynthesis?
- Light intensity
- Temperature
- Carbon dioxide concentration
- Water availability
