During glycolysis, ………………. molecules of `NADH_(2)` are formed.

Explanation

### Step-by-Step Text Solution:

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

2. **Process of Glycolysis**: The process begins with glucose, which is a six-carbon sugar. Through a series of enzymatic reactions, glucose is broken down into two three-carbon molecules of pyruvate.

3. **Formation of NADH**: During glycolysis, specifically in the conversion of glyceraldehyde 3-phosphate to 1,3-bisphosphoglycerate, NAD+ is reduced to NADH. This is a key step in the glycolytic pathway.

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