Which of the following conversions involve ATP synthesis during glucolysis?

Options

A. Glucose `rarr` Glucose-6-phosphate
B. Fructose-6-phosphate `rarr` Fructose-1,6-biphosphate
C. 1,3-bisphonsphoglyceric acid (BPGA) `rarr` 3-phosphoglyceric acid (PGA)
D. All of these

Explanation

To determine which conversions involve ATP synthesis during glycolysis, we need to analyze the glycolysis pathway step by step. Here is a detailed breakdown:

### Step-by-Step Solution:

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

2. **Initial Steps**: The glycolysis pathway begins with glucose, which is phosphorylated to form glucose-6-phosphate (G6P). This step does not involve ATP synthesis; rather, it consumes ATP.

3. **Conversion to Fructose**: Glucose-6-phosphate is converted to fructose-6-phosphate (F6P), which also does not involve ATP synthesis.

4. **Formation of Fructose-1,6-bisphosphate**: Fructose-6-phosphate is then phosphorylated to form fructose-1,6-bisphosphate (F1,6BP). This step also consumes ATP and does not produce ATP.

5. **Splitting into Two Products**: Fructose-1,6-bisphosphate is split into two three-carbon molecules: glyceraldehyde-3-phosphate (G3P) and dihydroxyacetone phosphate (DHAP). No ATP is produced in this step.

6. **Conversion of G3P**: Glyceraldehyde-3-phosphate is converted into 1,3-bisphosphoglycerate (1,3BPG). During this conversion, NAD+ is reduced to NADH, but there is no ATP synthesis.

7. **ATP Formation**: The first ATP synthesis occurs when 1,3-bisphosphoglycerate is converted to 3-phosphoglycerate (3PG). In this step, an ATP molecule is produced from ADP through substrate-level phosphorylation.

8. **Further Conversions**: 3-phosphoglycerate is then converted to 2-phosphoglycerate (2PG), and this step does not involve ATP synthesis.

9. **Conversion to Phosphoenolpyruvate (PEP)**: 2-phosphoglycerate is converted to phosphoenolpyruvate (PEP), which again does not produce ATP.

10. **Final ATP Formation**: The second ATP synthesis occurs when phosphoenolpyruvate is converted to pyruvate. This step also produces an ATP molecule from ADP through substrate-level phosphorylation.

11. **Total ATP Production**: In total, glycolysis produces 2 ATP molecules directly from the substrate-level phosphorylation steps mentioned above.

### Conclusion:
The conversions that involve ATP synthesis during glycolysis are:
- From 1,3-bisphosphoglycerate to 3-phosphoglycerate (producing 1 ATP).
- From phosphoenolpyruvate to pyruvate (producing another ATP).