Dissolving the sugar cube in water is a physical change. It doesn't alter the sugar's chemical structure like burning it or breaking it down with acid.
Answer:
With protein kinase activation, a lot of enzymes are phosphorylated by other enzymes.
Explanation:
Hormones often cause multiple responses in a cell because they activate a cascade where the protein kinase activation, phosphorylation, and activation of one enzyme result in the phosphorylation and activation of another enzyme, and so on. This cascade of activation has multiple effects on the cell.
