I. How Glucose Reaches Body Cells, cont. Ways that Big Molecules Enter Cells. Take in random samples of surrounding fluid. See Becker fig. See Becker fig.
Cells take in specific substances from surrounding fluid using a receptor.
See Becker fig. Need specific receptor for each substance transporte d 2 . Concentrates substance transported 3 . Clathrin is coat protein for vesicles forming from plasma membrane and trans-Golgi. Exocytosis balances endocytosis so cell surface area stays the same.