During aerobic respiration, all the ATP are synthesized as a result of

• Oxidative Phosphorylation:
  • It is the metabolic route in which electrons are transported from electron donors to electron acceptors in redox reactions that releases energy that is used to produce ATP.
  • Electrons are exchanged between molecules during this process, resulting in a chemical gradient that permits ATP to be produced.
  • The electron transport chain, which produces more ATP than any other element of cellular respiration, is the most important part of this process.
• Substrate Level Phosphorylation: 
  • Although most of your ATP is produced in the mitochondria, some ATP can be produced in the cytoplasm through a process known as substrate-level phosphorylation.
  • The physical addition of a phosphate group to ADP results in the formation of ATP.
  • Phosphorylation at the substrate level has a fancy name, but it's a simple process.
  • An adenosine diphosphate (ADP), which is a unit of adenosine connected to two (di) phosphate groups, is used in this kind of phosphorylation.
  • A phosphate group is extracted from an intermediate chemical, referred to as a substrate, and given to the ADP in order to convert it to adenosine triphosphate.

Hence, two processes - Oxidative and Substrate level phosphorylation, both release ATP.