Final answer:
Caveolae and clathrin-coated pits are both used in endocytosis, where cell membrane structures internalize substances into the cell. Caveolae are associated with potocytosis for small molecules, while clathrin-coated pits are involved in receptor-mediated endocytosis for larger substances.
Step-by-step explanation:
Caveolae and clathrin-coated pits are specialized structures on the cell membrane involved in endocytosis, which is a process where cells ingest external substances by engulfing them within a portion of the plasma membrane. Caveolae utilize the protein caveolin for the formation of vesicles, while clathrin-coated pits rely on clathrin to form clathrin-coated vesicles. Both structures facilitate the internalization of substances into the cell and are not involved in exocytosis (exporting substances) or phagocytosis (ingesting large particles or cells).
Caveolae-mediated endocytosis, also known as potocytosis, is predominantly used for the uptake and transcytosis of small molecules. On the other hand, clathrin-coated pits form clathrin-coated vesicles, primarily involved in receptor-mediated endocytosis, which is specific for larger molecules recognized by cell-surface receptors.