At the end of glycolysis, X is the net energy gain from one molecule of glycose via Y, but there is also energy stored in the form of Z. Identify X,Y and Z.

Options

A. `{:(X,Y,Z),(1ATP,"Oxidative phosphorylation",NADH+H^(+)):}`
B. `{:(X,Y,Z),(2ATPs,"Oxidative phosphorylation",NADH+H^(+)):}`
C. `{:(X,Y,Z),(1ATP,"Substrate level phosphorylation",FADH_(2)):}`
D. `{:(X,Y,Z),(2ATPs,"Substrate level phosphorylation",NADH +H^(+)):}`

Answer

To solve the question, we need to identify three components: X, Y, and Z, based on the process of glycolysis.

### Step-by-Step Solution:

1. **Understanding Glycolysis**: Glycolysis is the metabolic pathway that converts glucose into pyruvate, producing energy in the form of ATP and NADH in the process. It occurs in the cytoplasm of the cell.

2. **Identifying X (Net Energy Gain)**: During glycolysis, a net gain of ATP occurs. Specifically, for each molecule of glucose that undergoes glycolysis, a total of 2 ATP molecules are produced. This is the net energy gain from glycolysis.

3. **Identifying Y (Process)**: The process through which this energy is gained is known as substrate-level phosphorylation. In this process, a phosphate group is directly transferred from a substrate to ADP, forming ATP.

4. **Identifying Z (Stored Energy)**: In addition to ATP, glycolysis also produces NADH (nicotinamide adenine dinucleotide + hydrogen). NADH is a carrier of electrons and can be used later in cellular respiration to produce more ATP. Therefore, the energy is also stored in the form of NADH.

### Final Answers:
- **X**: 2 ATP (net energy gain)
- **Y**: Substrate-level phosphorylation (the process)
- **Z**: NADH + H+ (energy stored)