Photosynthesis - Chapter 11 Flashcards
What is photosynthesis carried out by, and what organisms are they ?
Carried out by plants + algae, they are autotrophic
Organisms such as animals cannot photosynthesis, where do they get their nutrients from, and what type of organism is an animal ?
They get their nutrients by eating plants or other animals
Animals are heterotrophic organisms
What is the reaction for photosynthesis and where does it take place?
6CO2 + 6H20 ~> C6H12O6 + 6O2
~> = energy from light
Reaction takes place in the chloroplasts
Where do light dependent reactions take place, and what light dependent reactions involve?
On the thylakoid membrane.
They can only happen in the presence of light
In light-dependent reactions, light energy is harvested and used to produce ATP + a reduced hydrogen carrier (NADPH)
It also involves water splitting , forming oxygen
Where do light independent reactions take place ?
In the stroma , they do not require light to function
What do the light independent reactions use from the light dependent reactions?
They use the ATP and reduced NADP produced in the light dependent reactions.
In the light independent reactions, glucose is produced from CO2.
What happens to the light dependent and light independent reactions if light is not present ?
If light is not present, the light dependent reactions stop, the levels of ATP and NADPH then fall, causing the light independent reactions to stop.
What do thylakoid membranes contain?
Light-harvesting pigments such as chlorophyll + and range of proteins needed for the light dependent reactions .
What is chlorophyll and the different forms ?
Chlorophyll is a pigment which absorbs visible light
Several different forms : chlorophyll a, chlorophyll b
What is chlorophyll a ?
The central molecule in the light dependent reactions.
Primary pigment.
Chlorophyll a works with a range of proteins/ other molecules : reaction centre
What is a photo-system ?
Together the reaction centre + light harvesting system
What are the wavelengths of both photo systems ?
Photosystem 1 : absorbs light with 700nm wavelength
Photosystem 2: absorbs light with 680nm wavelength
