Which of the following occurs through an anabolic pathway ?

Options

A. Conversion of glucose into lactic acid
B. Formation of proteins from amino acids
C. Formation of acetyl CoA from pyruvate
D. All of these

Answer

To determine which of the following occurs through an anabolic pathway, we need to analyze each option provided:

1. **Conversion of glucose into lactic acid**:
- This process involves glycolysis, where glucose is broken down into pyruvate, followed by anaerobic respiration that converts pyruvate into lactic acid. Since this process involves the breakdown of glucose into a simpler molecule (lactic acid), it is a catabolic pathway.
- **Conclusion**: This option is incorrect.

2. **Formation of proteins from amino acids**:
- In this process, amino acids (the building blocks or monomers) are linked together to form proteins (the polymers). This synthesis requires energy input, as it builds complex molecules from simpler ones. Therefore, this is an anabolic pathway.
- **Conclusion**: This option is correct.

3. **Formation of acetyl-CoA from pyruvate**:
- This process occurs during aerobic respiration, where pyruvate is converted into acetyl-CoA. This conversion is part of the breakdown of glucose and is involved in energy production. Thus, it is a catabolic pathway.
- **Conclusion**: This option is incorrect.

4. **All of these**:
- Since we have identified that two of the options are catabolic pathways and only one is anabolic, this option cannot be correct.
- **Conclusion**: This option is incorrect.

Based on the analysis, the correct answer is **formation of proteins from amino acids**, which occurs through an anabolic pathway.

### Summary of Steps:
1. Analyze the conversion of glucose into lactic acid - identified as catabolic.
2. Analyze the formation of proteins from amino acids - identified as anabolic.
3. Analyze the formation of acetyl-CoA from pyruvate - identified as catabolic.
4. Evaluate the option "All of these" - identified as incorrect.