Active Transport

• Molecules moved through a membrane against a concentration gradient use a carrier protein, requiring ATP
• When molecules are too large to be moved across a membrane, even through a carrier protein, they can be moved by bulk transport
• Exocytosis involves vesicles joining to the plasma membrane to release the vesicle contents to the external environment
• Endocytosis involves a body from the external environment being invaginated by the plasma membrane, and enclosed in a vacuole within the cell
• Endocytosis can be either phagocytosis or pinocytosis
• Define active transport?

  Movement of molecules across a cell membrane that requires energy.
• Define ATP and it’s use?

  Adenosine triphosphate. Energy currency in cells.