In the process of alcohol fermentation, 2 NADH molecules are converted to 2 NAH+ as energy from the NADH is used to drive the formation of ethanol. Explain why there is a need to add energy to a process whose purpose is to extract energy from glucose.
I thought it would be that you need energy for the action of extracting energy from glucose but I'm not sure...
You're on the right track! In the process of alcohol fermentation, the ultimate purpose is to extract energy from glucose. However, the conversion of NADH to NAD+ is a crucial step in this process, and it requires a small amount of energy input.
Let's break it down further:
1. First, glucose is broken down through a series of metabolic reactions (glycolysis) to produce energy-rich molecules called NADH. This step does release a small amount of energy, but it is not enough to drive the conversion of NADH to NAD+ on its own.
2. NADH is an "energy carrier" molecule, meaning it can transfer high-energy electrons produced during glucose metabolism to other reactions in the cell that require energy. In alcohol fermentation, NADH is involved in the synthesis of ethanol. However, for the conversion of NADH to NAD+ to occur, some additional energy is needed.
3. By adding energy, usually in the form of ATP (adenosine triphosphate), to the system, it provides the necessary input to convert NADH to NAD+. This conversion regenerates the NAD+ molecules required for glycolysis to continue, allowing the extraction of energy from glucose to proceed.
4. The ATP used in this process is ultimately derived from the breakdown of glucose itself, so the net energy gain from fermentation is still positive despite the small energy input required for NADH conversion.
In summary, the need to add energy to the process of alcohol fermentation allows for the conversion of NADH to NAD+, which is essential for glycolysis to continue. This ensures the continuous production of ATP and enables the extraction of energy from glucose.