Photosynthesis Flashcards
(28 cards)
What is photosynthesis ? 2
- the physiological process by which plants convert light energy from sun light to chemical energy.
whats autotrophic nutrition ? 1
- where the organism makes its own food
equation of photosynthesis ? 1
what else does it require- e…….?1
- 6CO2 + 6H2O + Sunlight ———> C6H12O6 + 6O2
- require electrons
why is photosynthesis helpful towards the planet ?2
- it is an example of carbon fixation , it takes in CO2 and also it releases O2
what is the respiration equation compared to the photosynthesis equation ? 1
- the opposite way around
what is it called when in the plant , the respiration rate is equal to the photosynthetic rate? 1
- compensation point
what are the two umbrella stages under photosynthesis ?
2
- The Light dependant stage
- The light independent stage
what are the 4 parts of the LDS? 4
1-light harvesting in photosystems (PSI & PSII)
2-Photolysis of water
3-Photophosphorylation to produce ATP in presence of light
4-fromation of reduced NADP
What’s photolysis of water ?
where does it take place ?
2
- splitting of water in the presence of light
- thylakoid membrane of PSII (p680)
whats the equation of the photolysis of water ? 1
- 2H2O—> 4H+ + 4e- + O2
why’s water so important ?
4 points but 6 marks
- keep plant turgid
- produced protons needed for Photophosphorylation
- electrons are used to replace the electrons in the chlorophyll which are lost when the light strikes
- O2- used for respiration or diffuses out of the leaf
What’s Photophosphorylation ? 2
how many types ?
- generation of ATP FROM ADP and Pi in the presence of light .
- two types = cyclic and non cyclic
what’s the difference between cyclic and non cyclic photophosphorylation ?
2
SIMILARTITES ? 2
- cyclic = only in PSI- produces ATP but only in smaller quantities than non cyclic
- Non cyclic = in both PSI +; PSII , produces O2 , ATP and reduced NADP
- BOTH involve iron containing proteins embedded in the thylakoid membrane that accept and donate electrons from the electron transport system …
outline non cyclic phosphorylation ?
5
- photon is excited at p680
- 2H2O—–>4H+ + 4e- + O2
water splits to replace the e- which was excited
3.electrons travel down energy levels from PSII - the energy released as electrons travel down transport chain pump H+ ions into the thylakoid lumen interior from the stroma
5.proton gradient is created for the diffusion later on
what does cyclic photophosphorylation produce ? 1
-ATP
What does non cyclic photophosporylation produce ? 3
- reduced Nadp
- ATP
- Oxygen
why is it called the light independent stage ? 1
- doesn’t use light energy
what name is given to the series of reactions whereby CO2 is converted to organic molecules ? 1
- Calvin Cycle
what is the product of the calvin cycle ? 1
- TP
How many turns of the calvin cycle make one glucose molecule ? 1
-6 turns needed to make glucose (2xTP)
what products are used from The light dependant stage in the calvin cycle …
2
- NADPH
- ATP
For every co2 fixed how many ATP are used to turn GP –> TP ? 2
- for every CO2 fixed : 2 ATP are used
1: 2
3 turns of the calvin cycle produces how many TP ?
How many are used to regenerate RuBp ?
2
- 6xTP
- 5 are used to regenerate the RUBP
How can we remember the calvin cycle ?
3 words - in hindi
NAME THE process that occur in the middle i.e. fixation etc
6
RuBy PaGAl ToPper
-starts with RUBY = RUBP ( 5 carbon sugar )
CO2 is added = FIXATION to make unstable 6 carbon compound —-> breaks down
-PaGAl :then GP is produced ( 2xGP = 2x3 carbon sugars )
REDUCTION (in biology means adding Hydrogen from NADPH—?NADP+ + Hydrogen )
-then ToPper : TP (2xTP)
REGENERATION occurs to form more RuBP.
