Which is not an endocrine gland?

1 pancreas
2 thymus
3 parathyroid
4 stomach

true                                                                                                       true true true true true true

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.