To determine which two substances cells need in order to make NADH, we need to understand the biochemical process involved.
NADH stands for Nicotinamide Adenine Dinucleotide (in its reduced form). It is an important coenzyme found in all living cells. The key to forming NADH is the reduction of NAD^+ (the oxidized form of the coenzyme). During cellular respiration, NAD^+ accepts electrons (and protons) and gets converted into NADH.
1. NAD+ (Nicotinamide Adenine Dinucleotide): NAD+ is the oxidized form of NAD. It is crucial in the electron transport chain and needs to be reduced to form NADH. This means it is one of the necessary components.
2. H+ (proton): In order to convert NAD+ into NADH, a proton (H+) is also required in the reaction. This proton, along with an electron, is added to NAD+ to form NADH.
Based on this, the two substances required to make NADH are:
- NAD+
- H+
Thus, the correct choices are:
- [tex]$\text{C. NAD}^+$[/tex]
- [tex]$\text{D. H}^+$[/tex]
Therefore, the two substances that cells need in order to make NADH are substances C (NAD+) and D (H+).
