What molecules carry the energy derived from breaking down glucose? Where are these molecules made?
Now, I'm thinking ATP and NADH but I'm not sure. Both these molecules are made outside the mitochondria in the cytoplasm.
That's correct! The molecules that carry the energy derived from breaking down glucose are ATP (adenosine triphosphate) and NADH (nicotinamide adenine dinucleotide). ATP is often called the "energy currency" of cells because it is used to power various cellular activities.
During the process of glucose metabolism, ATP is produced through a series of reactions known as glycolysis, which takes place in the cytoplasm of the cell. Glycolysis converts glucose into two molecules of pyruvate, while generating a small amount of ATP. This ATP is produced through substrate-level phosphorylation, where a phosphate group is directly transferred to ADP (adenosine diphosphate) to form ATP.
NADH is also produced during glycolysis, specifically in the reaction where NAD+ (oxidized form) is reduced to NADH (reduced form). NADH carries the high-energy electrons removed from glucose during glycolysis and serves as an electron carrier in subsequent stages of cellular respiration.
Once glycolysis is complete, the pyruvate molecules are transported to the mitochondria for further energy extraction through a process called aerobic respiration. In the mitochondria, pyruvate undergoes further reactions, including the citric acid cycle and the electron transport chain. These processes generate additional ATP and NADH, which are used as energy sources by the cell.
Therefore, while ATP and NADH are initially produced in the cytoplasm during glycolysis, they play a crucial role in powering cellular processes within the mitochondria during aerobic respiration.