Photosynthese Flashcards
What does the chemiosmotic hypothesis explain?
The mechanism of ATP synthesis in chloroplasts
Where does proton accumulation occur during photosynthesis?
In the lumen of the thylakoids
How does the proton gradient develop across the thylakoid membrane?
Through the splitting of water and electron transport processes
What happens to protons during the splitting of water molecules?
They accumulate within the lumen of the thylakoids
What is the primary accepter of electrons in the thylakoid membrane?
An H carrier
What role does NADP reductase play in ATP synthesis?
It reduces NADP+ to NADPH + H+ using protons from the stroma
What is the effect of proton accumulation in the lumen on pH?
It causes a measurable decrease in pH in the lumen
Why is the proton gradient important?
It leads to the synthesis of ATP when it is broken down
What are the two parts of the ATP synthase enzyme?
CF0 and CF1
What does the CF0 part of ATP synthase do?
It forms a transmembrane channel for facilitated diffusion of protons
What is the function of CF1 in ATP synthase?
It protrudes on the outer surface of the thylakoid membrane and is involved in ATP synthesis
What is required for chemiosmosis to occur?
A membrane, a proton pump, a proton gradient, and ATP synthase
What does the breakdown of the proton gradient provide?
Enough energy to cause a conformational change in CF1 for ATP synthesis
Fill in the blank: ATP synthase catalyses the formation of _______.
ATP
What is the immediate use of ATP and NADPH produced during photosynthesis?
In the biosynthetic reaction for fixing CO2 and synthesis of sugars
