c1.1 - importance of ATP Flashcards
ATP
adenosine triphosphate
universal energy carrier found in all living cells
where is ATP produced
synthesised in the internal membranes of mitochondria + chloroplasts
how is ATP synthesised
involves ATP synthase - enzyme found embedded in cellular membranes
ATP synthase phosphorylates ADP to form ATP as protons flow through it, down electrochemical gradient
flow of protons across mitochondrial v chloroplast membrane
mitochondrial - H+ flow across inner membrane, from intermembrane space into matrix
chloroplast - H+ flow across thylakoid membrane, from thylakoid space into stroma
chemiosmosis
synthesis of ATP through movement of protons across partially permeable membrane, catalysed by ATP synthase
as protons move down, energy is released for attachement of inorganic phosphate to ADP forming ATP
how is proton gradient maintained during chemiosmosis
potential energy associated with excited electrons is coupled to active transport of H+ across membrane by proton pumps
electron transport chain
series of electron carrier proteins each w/ progressively lower energy levels that transfer electrons in chain of oxidation-reduction reactions, forming gradient of protons that enables ATP synthesis
how can dehydrogenase activity be investigated
using artificial hydrogen acceptors
e.g: DCPIP, methylene blue, terazolium compounds
colour change when DCPIP is reduced
blue to colourless
colour change when methylene blue is reduced
blue to colourless