Questions: What is the function of casein in milk?

The answer is the third one: Supply amino acids for growth.

Explanation for each option:

1. Aid in digestion: Casein is not primarily involved in aiding digestion. It is a protein that is digested in the stomach, but its main role is not to facilitate digestion.

2. Enhance flavor: Casein does not enhance the flavor of milk. It is a protein that contributes to the nutritional value rather than the taste.

3. Supply amino acids for growth: This is the correct answer. Casein is a major protein in milk that provides essential amino acids necessary for growth and development, especially in infants and young animals.

4. Provide energy: While proteins can be used as an energy source, this is not the primary function of casein. Its main role is to supply amino acids for growth and repair.

In summary, the primary function of casein in milk is to supply amino acids for growth.