Final answer:
NADH produced in glycolysis in the cytosol enters the inner mitochondrial membrane (IMM) through shuttle systems such as the glycerol phosphate shuttle, allowing the electrons to contribute to the electron transport chain and ATP production.
Step-by-step explanation:
Electrons from NADH made in glycolysis enter the inner mitochondrial membrane (IMM) through shuttle systems, as glycolysis occurs in the cytosol. The electrons are transported into the mitochondria due to the impermeability of the mitochondrial membrane to NADH. Shuttle systems like the glycerol phosphate shuttle facilitate this process.
During glycolysis, NADH is produced in the cytosol and needs to be oxidized in the electron transport chain (ETC) to form ATP, a process occurring inside the mitochondria. Once in the mitochondria, electrons from NADH are passed through the ETC, contributing to the formation of a proton gradient that drives the production of ATP through chemiosmosis. Thus, without these shuttles, the NADH electrons could not contribute to the process of oxidative phosphorylation, and aerobic respiration efficiency would be greatly reduced.