Photosynthesis Flashcards
What is an organic compound?
A compound that contains a carbon atom
What is an inorganic compound?
One that doesn’t contain carbon
What is oxidation?
O I L R I G Oxidation is loss of hydrogen or gaining oxygen
What is a co enzyme?
Non protein molecule that help enzymes to function eg) NAD
What is phosphorylation?
Adding a phosphate eg) ADP + Pi
What is photophosphorylation?
Using light to add a phosphate.
What uses light to split a molecule?
Photolysis
What is an ETC?
Where electrons flow through proteins in a membrane
What is a proton?
A positive charge eg) H+
What is a chloroplast?
An organelle that absorbs light energy to be used for photosynthesis, to make useful organic compounds
What is a thylakoid?
Membrane is the site of the light dependant reaction, high SA, contains photosynthetic pigments. Eg) chlorophyll A+B and carotene
Why is photosynthesis important?
It converts light energy into chemical energy (stored in carbs) This allows the energy to be transferred to other organisms by consumption
What is the chemical equation of photosynthesis?
6CO2 + 6H2O ———> 6O2 + C6H12O6
Where does the light dependant reaction take place?
Chlorophyll (thylakoid membrane)
Describe the light dependant reaction. (5 steps)
The light energy is absorbed by photosynthetic pigments in the chlorophyll
This excites the electrons they leave the chloroplasts which is then photoionised
The electrons are transferred through5 a carrier molecule in the thylakoid membrane
as electrons move down the ECT they use energy to pump protons from the stroma into the thylakoid creating a proton gradient
The protons diffuse out via the ATP synthase enzyme releasing energy for the Phosphorylation of ADP +Pi to ATP. ( chemiosmosis)
name 3 photosynthetic pigments
chlorophyll A, chlorophyll B, carotene
What are the products of the light dependent reaction?
ATP + NADPH
What is the role of the Calvin Cycle?
uses products of LDR to make useful organic products from CO2
What is the first stage of the calvin cycle?
CO2 (1C) combines with RUBP (5C) catalysed by the enzyme rubisco to make 2 molecules of GP (3C each)
What is stage 2 of the calvin cycle?
Both molecules of GP (3C each) are reduced by LDP products (ATP —-> ADP and NADPH—–> NADP) to form 2 TP (3C each)
what is stage 3 of the calvin cycle?
most TP is regenerated to form RUBP, some TP is used to make useful organic compounds eg) glucose
How many extra carbons are there per spin of the calvin cycle?
1
Name 3 limiting factors of photosynthesis
Temperature, CO2 conc, light intensity
Light intensity as a limiting factor
higher the light intensity the more energy there is for the LDR so the faster the rate of photosynthesis
light needs to be of teh right WL
CO2 conc as a limiting factor
optimum CO2 is 0.4% atmosphere is 0.04% in atmosphere
limiting factor during the day
Temperature as a limiting factor
Increases KE increasing Enzyme action
can increase transpiration — stomata close
How can farmers use light intensity to increase yield?
use a green house
use light of correct wavelength
How can farmers use CO2 to increase yield?
fossil fuel burner increases CO2 conc
How can farmers use temperature to increase yield?
burner increases temp
greenhouse traps warm air
maintain optimum temperature using thermostat
