While the release of bioactive chemicals by the plant to protect itself from the insects attack is a

adaptation to avoid predators, while the release of bioactive chemicals by the plant to protect.

many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.