A source of maximum energy is

Options

A. Carbohydrate
B. Fat
C. Protein
D. Vitamins.

Answer

To determine the source of maximum energy among carbohydrates, fats, proteins, and vitamins, we can analyze the energy yield from each of these biomolecules.

### Step-by-Step Solution:

1. **Understanding Energy Sources**:
- Energy in living organisms is derived from the oxidation of biomolecules. The primary biomolecules include carbohydrates, fats, proteins, and vitamins.

2. **Analyzing Carbohydrates**:
- Carbohydrates, such as glucose, are a common energy source. The complete oxidation of one molecule of glucose yields approximately 30 ATP molecules.

3. **Analyzing Fats**:
- Fats, particularly in the form of triglycerides, are composed of glycerol and fatty acids. Fatty acids are highly reduced molecules, meaning they contain more hydrogen atoms relative to oxygen.
- For example, the oxidation of one molecule of palmitate (a 16-carbon saturated fatty acid) can yield about 106 ATP molecules.

4. **Analyzing Proteins**:
- Proteins are broken down into amino acids. These amino acids can be used to synthesize new proteins or can be converted into intermediates for energy production. However, the energy yield from proteins is generally lower than that from fats.

5. **Analyzing Vitamins**:
- Vitamins are essential nutrients but do not serve as a direct source of energy. They play roles as coenzymes and are crucial for various metabolic processes but do not provide energy directly.

6. **Conclusion**:
- Among carbohydrates, fats, proteins, and vitamins, fats provide the maximum energy upon oxidation. Therefore, the source of maximum energy is **fats**.

### Final Answer:
The source of maximum energy is **fats**.