Which of the following accurately describes the action of rennin, and its effect on a specific substance, considering varying pH levels?
Rennin acts on milk, converting casein into calcium para-caseinate within the pH range of 7.2-8.2.
Rennin primarily acts on proteins in the stomach, regardless of pH.
Rennin targets fat in the intestine, with no pH dependency.
Rennin acts on milk, transforming casein into calcium para-caseinate within the pH range of 1-3.
Rennin is an enzyme that acts on milk, specifically on a protein called casein. It works best in the acidic environment of the stomach, where the pH is typically between 1 and 3. In this pH range, rennin transforms casein into a substance called calcium para-caseinate. This reaction helps in the digestion and coagulation of milk proteins, making them easier to absorb and use. Hence, the correct answer is option 4.