Final answer:
NADH has the capacity to transport three hydrogen ions (3 H+) across the mitochondrial membrane into the intermembrane space during the electron transport chain, contributing to ATP synthesis and body heat generation.
Step-by-step explanation:
The electron transport chain (ETC) is a crucial part of cellular respiration, and NADH plays an important role in this process. When NADH donates electrons to the ETC at Complex I, it facilitates the transport of hydrogen ions across the membrane.
Specifically, NADH has sufficient energy to transport three hydrogen ions (3 H+) into the intermembrane space of mitochondria. This contributes to the formation of an electrochemical gradient known as the proton motive force, which drives the synthesis of ATP through oxidative phosphorylation.
FADH2 also contributes to the electron transport chain but enters at Complex II, resulting in the transport of two hydrogen ions (2 H+) into the intermembrane space. The energy released from these redox reactions, where NADH is oxidized to NAD+, is also partially used to generate heat, playing a role in thermoregulation of the body.