Topic 5 - Energy Transferes In And Between Organisms Flashcards
Phosphorylation and photophosphorylation
Adding phosphate molecules
Adding phosphate using light energy
Photolysis
Splitting of molecule using light
Water molecule in PS2 slip by light releasing 2 electrons to replace ones moved away down ETC.
O2 also produced
Photoionisation
Light excited electrons in an atom giving them more energy causing them to be released
Chloroplast
- chlorophyll
- thylakoid
- grana
- lamellea
- stroma
LDR summary
- requires light
- electrons excited
- electrons transfere energy to PS1
- phosphate added to ADP to make ATP and reduce NASP
- hydrogen transferred
LIR summary
- Calvin cycle
- relays on products from light dependent reaction
- in stroma
- atp and reduce nadp supplies energy and h for simple sugars from CO2
Photophophorylation: cyclic and non cyclic
Non cyclic - produces atp reduced nadp and O2. Non-cyclic because electrons moved from PS2 dont return to PS2
Cyclic - produces atp. Electrons from PS1 return back to PS1
Where does the light independent reaction t ake place
Stroma
DCPIP? What is it?
Blue when oxidised
Colourless when reduced by electrons
- chemical that shows rate of photosynthesis
What inhibits decolorisation:
- less ATP
- less reduced nadp
- less gp to top
LDP KEY POINTS
- light hits chloroplast and excited electrons which more from PS11 to PS1 and transference energy as the move down ETC
- energy used in Active T to diffuse H+ into thylakoid
- h+ reduce nadp
- h+ diffuse through atp synthase and produce atp for Calvin cycle
LDR photoionisation
- chlorophyll absorbs light
- electron excited
- electrons lost ???
- chlorophyll positively charged
LIR KEY POINTS
- Calvin cycle
- rubisco enzyme catalyses reaction between CO2 and RuBP
- 2x G3P formed from unstable 6 carbon compound
- ATP and RNADP from LDR converts GP to TP (2x 3C)
- 1 carbon released from TP
- TP converted to 5 carbon compound RuBP again by ATP
- cycle repeats 6x to make hexose sugar
Advantages of having different pigment
All absorb different wavelengths of light for photosynthesis
Where is rubisco found ?
Stroma in chloroplast
Two products of LDR require for LIR
ATP
NADPH (reduced)
Hydrolysis from atp
What are the h+ ions that travel fin to the thylakoid during LDR
- proton from stroma diffuse via AT into thylakoid
- creates proton gradient in thylakoid membrane
Photolysis of water ???
- light splits water into electrons protons and oxygen
- electrons replace those lost from pigments during photoionisation
- protons are used for ATP production
- protons and electrons reduce NADP
What converts GP to TP
ATP
NADPH
Optimum conditions for photosynthesis
- high light intensity Of certain wavelength
- temperature of around 25 degrees C
- CO2 at 0.4% ( any higher and stomata might close
- constant supply of water (too much cases water logging or suffocates plant)
Limiting factors of photosynthesis
- all at right level manage the constant rate of photosynthesis
- anyone too high or too low can limit it
- saturation point if when one factor has reached max amount and is no longer limiting factor because something else is limiting
What do farmers do to manage limiting factors to ensure plants grow to the max rate and max yield
- CO2 added to air in greenhouse by burning propane in CO2 generator
- light provided by lamp
- temperature maintained by sunlight trapped in greenhouse but heating and cooling systems maintain constant temp and air circulation can be controlled
What is mobile and stationary phase in chromatography
- mobile - molecules move due to liquid solvent
- stationary - can’t move
Aim of glycolysis
Glucose to pyruvate