In computational complexity theory, a problem refers to the abstract question to be solved. In contrast, an instance of this problem is a rather concrete utterance, which can serve as the input for a decision problem. For example, consider the problem of primality testing.
Oxygen plays a vital role in both the aerobic and anaerobic metabolic systems. While oxygen is required as a direct energy source in the aerobic system, it is also essential in clearing the blood of excess lactic acid buildup in the anaerobic system.
Anaerobic respiration is respiration without oxygen; the process uses a respiratory electron transport chain but does not use oxygen as the electron acceptors. Cells that use it. Aerobic respiration occurs in most cells.naerobic respiration is respiration without oxygen; the process uses a respiratory electron transport chain but does not use oxygen as the electron acceptors. Cells that use it. Aerobic respiration occurs in most cells.