A person is undergoing prolonged fasting. His urine will be found to contain abnormal quantities of –

Options

A. Fats
B. Amino acids
C. Ketone body
D. Glucose

Answer

### Step-by-Step Solution:

1. **Understanding Prolonged Fasting**: When a person undergoes prolonged fasting, the body starts to utilize its energy reserves. Initially, glucose is used, but as fasting continues, the body begins to break down fats and proteins for energy.

2. **Metabolism During Fasting**: During fasting, the liver increases the breakdown of fatty acids to produce energy. This process leads to the formation of ketone bodies as a byproduct. Ketone bodies are produced from the oxidation of fatty acids and are used as an alternative energy source when glucose levels are low.

3. **Formation of Ketone Bodies**: The primary ketone bodies produced in the liver are acetoacetate, beta-hydroxybutyrate, and acetone. These compounds enter the bloodstream and can be used by various tissues, including the brain, as an energy source.

4. **Excretion of Ketone Bodies**: When the concentration of ketone bodies in the blood increases, the kidneys filter them out, leading to their presence in urine. This condition is known as ketonuria, which is characterized by the abnormal presence of ketone bodies in the urine.

5. **Conclusion**: Therefore, during prolonged fasting, the urine will contain abnormal quantities of ketone bodies due to increased fatty acid oxidation and the subsequent production of ketone bodies in the liver.

### Final Answer:
The urine will be found to contain abnormal quantities of **ketone bodies**.

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