What are the by-products of the breakdown of glucose in aerobic respiration?

The by-products of the breakdown of glucose in aerobic respiration are carbon dioxide, water, and energy in the form of ATP.

In aerobic respiration, glucose is broken down in the presence of oxygen to produce carbon dioxide, water, and energy. This process occurs in three main stages: glycolysis, the Krebs cycle, and the electron transport chain.

Glycolysis, which takes place in the cytoplasm of the cell, involves the splitting of one molecule of glucose into two molecules of pyruvate. This process produces a small amount of ATP and also generates NADH, a molecule that carries electrons to the next stage of respiration.

The Krebs cycle, also known as the citric acid cycle, occurs in the mitochondria. Here, each pyruvate molecule is further broken down, releasing carbon dioxide as a by-product. This cycle also generates more NADH, as well as FADH2, another electron carrier, and a small amount of ATP.

The final stage, the electron transport chain, is where the majority of the ATP is produced. The NADH and FADH2 molecules generated in the previous stages donate their electrons to this chain, which is a series of proteins embedded in the inner mitochondrial membrane. As the electrons move along the chain, they power the pumping of hydrogen ions across the membrane, creating a gradient. The flow of these ions back across the membrane drives the synthesis of ATP. The final electron acceptor in the chain is oxygen, which combines with the electrons and hydrogen ions to form water.

In summary, the breakdown of glucose in aerobic respiration produces carbon dioxide and water as by-products, along with a significant amount of ATP, the energy currency of the cell. This process is vital for life, as it provides the energy needed for all cellular activities.