3.1 - the importance of ATP

what is ATP? (2)

• adenine triphosphate

• the universal energy currency in all living cells

where is ATP produced?

on the internal membranes of chloroplasts and mitochondria

how is ATP synthesised? (ATP synthase)

ATPsynthase phosphorylates ADP to ATP as protons flow through it

compare the flow of protons across the mitochondrial and chloroplast membranes

• mitochondrial - H+ flow from the intermembrane space into the matrix, across the inner membrane

• chloroplast - H+ flow from the thylakoid space into the stroma, across the thylakoid membrane

define chemiosmosis

the synthesis of ATP through the movement of protons down their electrochemical gradient across a semi-permeable membrane, catalysed by ATPsynthase

how is the proton gradient maintained during chemiosmosis?

potential energy associated with excited electrons is coupled to the active transport of H+ across the membrane by proton pumps

what is the electron transport chain?

a series of electron carrier proteins that transfer electrons in a chain of redox reaction, releasing energy

how can dehydrogenase enzyme activity be investigated?

using artificial hydrogen acceptors such as DCPIP, methylene blue and tetrazolium compounds

what colour change is observed when DCPIP is reduced?

dark blue to colourless

what colour change is observed when methylene blue is reduced?

dark blue to colourless