Enzymes
What is the main purpose of the enzyme?
To act as a catalyst, speeding up chemical reactions, and lower the activation energy.
Where is light first absorbed, and what is the purpose to absorb it?
PSII
To excite electron
Where does it occur
the stroma
What is metabolism?
total sum of all chem rxns in bio system
What is the general equation to photosynthesis?
Sunlight + CO2 + H2O -> C6H12O6 + O2
What are the two models for enzymes?
Lock and key model
Induce fit model
To carry the electron to PSI. It also actively diffuses Hydrogen ions across the membrane
What are the 3 stages?
Carbon fixation, reduction of 3-pga, and regeneration of RuBP
What is the difference between endergonic and exergonic?
Exer -> Spont ( -Δ G) Release energy
Ender-> non spont (+Δ G) Takes energy
What is the major pigment at work to absorb the light?
Chlorophyll A
Name all the factors that can affect an enzymes rate of reaction.
substrate conc., enzyme conc., temperature, and pH
What would happen if light was to intense?
The chlorophyll may be damaged
How much ATP and NADPH does it take to make ONE glucose?
18 ATP
12 NADPH
Difference between Anabolic and Catabolic Reactions, and are they exergonic or endergonic?
Ana -> form complex molecules from simple, endergonic
Cata -> break complex to form simple, exergonic
What are the environmental conditions that affect rate of photosynthesis
light intensity, water availability, temperature, light color, conc of CO2, O2
What does it mean for an enzyme to denature? What can cause this? Why is it important?
Denature -> losses its shape
Cause -> temp or pH
Why? -> Enzyme can't work to speed up rxn
DOUBLE JEOPARDY (B/C it's a lot)
Describe the movement of hydrogen ions. State what ends up being generated as a result, and name the process.
Active diffuse via ETC
Passive diffuse through atp synthase (Chemiosmosis, name not needed for points)
generation of atp (Photophosphorylation, name needed for points)
Why is Oxygen considered an inhibitor for it?
because Rubisco no likey
Do reactions in general occur at a fast rate and why?
No, b/c random chance to collide plus need tight orientation
If you provide a plant a lot of water, why does its rate of photosynthesis start to cap out?
The large central vacuole can only hold so much water
What are the regulations that enzymes can be controlled by? (Hint could be given if need to clear the question.)
Non-comp inhib. -> bind to site not activation site
Comp inhib -> bind to active site
Why does the light independent reaction happen between the stroma and the lumen and not another membrane?
The hydrogen ions makes the inside acidic. Proteins would start to denature which would be bad for the cell
Why does it take place in the stroma instead of for example the lumen?
Can't be in lumen b/c too acidic due to H+ ions
enzymes would denature
Coupled reactions are very important for photosynthesis. In general, what would be an example of one within photosynthesis?
Example of a response:
Light gives energy, photosynthesis uses this to make ATP.
Plants need CO2 to do photosynthesis. When provided a surplus of it, plants only reach a maximum rate. Why is this? (I have a hint if needed)
Concentration of the substrates vs conc of enzymes. There's a lot of substrate (CO2), the enzymes can only do so much at a time