Cells require a structure that regulates the transfer of material in and out of the cell. This structure is the –
Cell membrane.
Answer:
The proton gradient produced by proton pumping during the electron transport chain is used to synthesize ATP. Protons flow down their concentration gradient into the matrix through the membrane protein ATP synthase, causing it to spin (like a water wheel) and catalyze conversion of ADP to ATP.
The specimen is VIRUS.
A virus is an infective agent which can only reproduce within a living cell. All virus contain genetic materials, either DNA or RNA but not both. A protein coat usually surround the genetic material of the virus. Virus can be classified based on the genetic material found in them and the size of the material.