Answer:
The ATP synthase can be thought of as a type of molecule motor that is powered by the flow of __H+_ through the subunits and __down_ their concentration gradient.
Explanation:
There are two steps for the synthesis of carbohydrates in plants; one is light reaction and other is dark reaction. In light reaction the ATP and NADPH are produced from sunlight and these molecules are utilized for combining the carbon molecules in dark reaction.
Before we discuss chemiosmosis (Mechanism of ATP production) we should know that light reaction takes place in the thylakoid membrane of chloroplast. During the light reaction electrons removed from water are excited by light in photosystem I and photosystem II. These excited electron release the energy while traveling down the electron transport chain which is utilized to pump the H+ ions to stroma from lumen. This build a concentration difference of H+ ions across the membrane.
So when these H+ ions flow from stroma to lumen i.e. higher potential to lower potential they passes through ATP synthase complex. ATP synthase produces the ATP by the phosphorylation of ADP that why mechanism is also referred as Photophosphorylation.
Answer:
1.protons
2.Down
Explanation:
The ATP Synthase is an enzyme which catalyses the phosphorylation ADP to ATP, for synthesis of ATPs in the matrix of mitochondria and stroma of chloroplast.
ADP + Pi → ATPs.
ATPsynthase.
The source of energy to power the ATP synthase is from the electrochemical gradient set up by diffusion of protons from the intramembrane layer of mitochondria and thylakoid membrane,down into the matrix or stroma where the ATPase synthase is located.
The force for the proton pump into the intramembrane is known as the Proton Motive Force.(PMF).it is set up by the electrical mechanisms of electron transport chain. It constantly pumps protons into the intramembrane layers, therefore setting up the electrochemical gradient.
The proton is obtained from the splitting of hydrogen atoms, carried by the co-factors NADH+ and FADH2,from the Krebs cycle into the matrix or stroma, into protons and electron.
H2→→→ H+ + e-.
This explains the ATP synthase activities for ATP synthesis.