Which is true of glycolysis

Options

A. In aerobic organisms, it is the only process in respiration
B. In this process glucose undergoes complete oxidation to form pyruvic acid
C. Enzyme hexokinase catalyses phosphorylation of glucose to glucose 6-phosphate
D. ATP is utilised in conversion of PEP to pyruvic acid

Answer

To determine which statement is true regarding glycolysis, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Statement Analysis**:
- **Statement 1**: "In aerobic organisms, it is the only process in respiration."
- **Analysis**: This statement is incorrect. Glycolysis is the first step in cellular respiration, but aerobic respiration also includes the Krebs cycle and oxidative phosphorylation. Therefore, glycolysis is not the only process in aerobic respiration.

2. **Statement 2**: "In this process, glucose undergoes complete oxidation to form pyruvic acid."
- **Analysis**: This statement is also incorrect. During glycolysis, glucose is partially oxidized to form pyruvic acid. The complete oxidation of glucose occurs later in the Krebs cycle and oxidative phosphorylation, where carbon dioxide and water are produced as end products.

3. **Statement 3**: "Enzyme hexokinase catalyzes phosphorylation of glucose to glucose 6-phosphate."
- **Analysis**: This statement is correct. Hexokinase is the enzyme that catalyzes the phosphorylation of glucose to form glucose 6-phosphate, which is the first step in glycolysis. This process involves the utilization of ATP.

4. **Statement 4**: "ATP is utilized in the conversion of phosphoenol pyruvate to pyruvic acid."
- **Analysis**: This statement is incorrect. In the conversion of phosphoenol pyruvate (PEP) to pyruvic acid, ATP is produced, not utilized. This reaction is catalyzed by the enzyme pyruvate kinase.

### Conclusion:
The only true statement about glycolysis is:
- **Enzyme hexokinase catalyzes phosphorylation of glucose to glucose 6-phosphate.**