Final answer:
The three main stages of cellular respiration are glycolysis, the Krebs cycle, and the electron transport chain. Glycolysis breaks down glucose into pyruvate, the Krebs cycle processes the pyruvate into CO₂ and harvests energy carriers, and the electron transport chain uses these to produce a high yield of ATP.
Step-by-step explanation:
The Three Main Processes of Cellular Respiration
The process of cellular respiration is a fundamental biological process which converts the energy stored in glucose into Adenosine Triphosphate (ATP). There are three main stages in cellular respiration: glycolysis, the Krebs cycle, and the electron transport chain.
Glycolysis
Stage one of cellular respiration is glycolysis. During glycolysis, one molecule of glucose, which contains six carbon atoms, is broken down into two molecules of pyruvate, each consisting of three carbon atoms. This process occurs in the cytoplasm and can happen with or without oxygen, resulting in a net gain of two ATP molecules and the reduction of NAD+ to NADH.
Krebs Cycle (Citric Acid Cycle)
Stage two follows glycolysis and occurs within the mitochondria. The pyruvate molecules undergo transformation to create Acetyl CoA, which then enters the Krebs cycle. This cycle is a series of reactions that produce CO₂, NADH, FADH₂, and a small amount of ATP. The mitochondria's inner membrane plays a crucial role here, with its folds, called cristae, increasing surface area for reactions.
Electron Transport Chain
Stage three is the electron transport chain, which also takes place in the mitochondria's inner membrane. The NADH and FADH₂ generated from previous stages donate their electrons to the chain, powering the production of a significant amount of ATP. This stage requires oxygen as the final electron acceptor, completing the process of aerobic respiration.
Altogether, these processes ensure that cells efficiently produce the energy required for their functions via the catabolization of glucose into ATP.