While hiking in the forest, paul came upon a bear hunting along the river. paul knows the best thing to do is to remain quiet and back away very slowly, but his body is suddenly primed to run away at full speed. the system is activated when paul first encounters the bear?

not too sure but maybe in the hot springs.

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.