In both cellular respiration and photosynthesis, a( built into a membrane pumps h+ across the membrane as electrons are passed from one electron carrier to the next in a series of redox reactions.

Electron Transport Chain

Explanation:

Electron transport Chain (ETC) is utilized both in cellular respiration and photosynthesis. In cellular respiration, it is a later stage whereas in photosynthesis it occurs earlier.

Electrons are passed through various complexes or electron carriers in ETC. During this process simultaneous oxidation and reduction of various molecules takes place. H+ gradient is generated across the membrane which is utilized by ATP synthase to generate ATP from ADP. While ATP is the final product in cellular respiration, in photosynthesis it is used to produce sugar molecule in the next stage which is Calvin cycle.

the sugar-phosphate backbone forms the structural framework of nucleic acids, including dna and rna. this backbone is composed of alternating sugar and phosphate groups, and defines directionality of the molecule.