Photosynthesis Flashcards
What are the two stages of photosynthesis?
Light dependent reaction, light indapendent reaction
How many atps does photosynthesis make?
2
What does the light dependent reaction produce?
Atpand nadph, nadph2 or rediveed nadp
Where does light dependent reaction take place?
Thylakoids and grana
What does the light independant reaction require ?
Products of ldr
What is the role of light independent reaction?
Reduces c02- c6h1206 (glucose)
What is a co enzyme?
Molecules that like to carry H to electron transport chain. They donate their H atom to the etc. Energy from the electron is used to generate atp.
What are the stages of the ldr?
Chlorophyll absorbs energy , 2 electrons are emitted from photoionisation. 2e- pass down an etc into the thylakoid membrane, energy is released and used to phosphorylate ADP. Light strikes h2o and splits into 2e- and 2h ( which are returned to chlorophyll) +1/2 C. Energy released during photolysis is used to pump h+ ions into the thylakoid space creating a proton gradient across thylakoids membrane. H+ ions move back across membrane via atp synthase enzyme which releases energy. Low energy e- +H+ combine to form H. This reduces the Co enzyme nadp
What is an electron transport chain?
Electron carriers that form a chain in the inner mitochondrial membrane, each electron carrier in the chain is at a lower energy level. co enzyme donates electrons to these carriers energy is released as electron moves down the etc
What products does lir need from ldr?
Atp nadph
Where does the light indapendent reaction occur?
In the stroma of the chloroplasts.
What are the limiting factors of photosynthesis?
Light intensity, light quantity, temperature,concentration of co2, chlorophyll concentration
What happens when something is reduced?
It is the gain of electrons
What happens when something is oxidised?
Oxidation is the loss of electrons
What are examples od co enzymes?
NAD, FAD, NADP
How many carbon molecules are used in the lir to regenerate RuBp?
5/6
What is RUBISCO?
It is the enzyme that catalyses the reaction between RuBp+ Co2
What are the steps of the lir/calvin cycle?
Co2 combines with acceptor molecule rubp. Rubisco catalyses this reaction producing an unstable 6c molecule which splits to form 2xgp. Gp is reduced to TP. hydrolysis of atp provides energy for this reaction. NADH forces electrons into gp reducing it. Tp is formed and converted to useful organic substances eg fructose/glucose. 5/6 carbons of tp is used to regenerate the acceptor molecule rubp. This ensures continued fixator of co2 and production of gp is remain
How do you measure CO2?
Measure vol of co2 absorbed in a given time
What is the NET rate of photosynthesis?
Volume of CO2 absorbed from the the atmosphere in a time period.
What is the GROSS rate of photosynthesis?
Atmospheric co2 used in photosynthesis plus, co2 produced in respiration that is used in photosynthesis
What do farmers do in summer to overcome limiting factors?
Ventilate greenhouse- to remove excess heat and replenish co2
What do farmers to overcome limiting factors in winter?
Enrich co2 concentration via combustion of co2 pellets, heat green houseses which removes temperature as a limiting factor, install lighting pannels illuminate crops for longer duration
