A group of proteins aligned in a membrane can form a(n) transport chain, which releases energy at each step in the chain and plays a role in both photosynthesis and respiration.

micro/nanoscale topography surface exhibits many prominent properties and is extensively employed in biomedical device, microfluidic device and energy device fabrication. additionally, the clinical applications of biomaterials can be largely expanded with of nanostructured surfaces.

i believe it is "they are not used up by reactions" as the answer to your question, text me back if this is correct because i just learned this.