What is the role of NADH in cellular respiration?

NADH plays a significant role in the process of cellular respiration. It is involved in the processes of the citric acid cycle and glycolysis, functioning as an electron carrier. More specifically, NADH accepts electrons from sugar molecules during the two processes and delivers them to the electron transport chain for ATP production. There are two forms of NADH, which are NAD+ and NADH. NAD+ is the oxidized form, and loses an electron, while NADH is the reduced form, which gains the electron lost by NAD+. NADH is also able to store energy, as it (alongside with FADH2 molecules) are used in the electron transport chain for the generation of the 32 ATP molecules. It is also important to note though NADH is vital to the metabolic activities of the cell; high levels of NADH are toxic. NADH accumulation occurs when cells do not receive enough oxygen or are unable to utilize it properly.