<span>Proline.
Is an amino acid which is a constituent of most proteins, especially collagen. In plants, proline accumulation is a common physiological response to various stresses but is also part of the developmental program in generative tissues.</span>
Answer:
well because of the salt in the water that is why it takes longer to freeze.
Explanation:
To test for it, use two containers, one which contains only water and the second should be one with salt solution.
then experiment the time each take to freeze.
hope it helps .
It is a membrane that is surround the cytoplasm of a cell. They help and protect the cell.