Biology Active and Passive Transport

Active and Passive Transport

• Diffusion:

  • A passive process where molecules (liquids, solutes, gases) move across a cell membrane, balancing concentrations inside and outside the cell.

• Facilitated Diffusion:

  • A passive transport method that utilizes specific transport proteins to help molecules cross the cell membrane without energy expenditure.

• Osmosis:

  • Passive diffusion specifically referring to the movement of water molecules across a semipermeable membrane, crucial for maintaining cellular balance.

• Ion Pumps:

  • An active transport mechanism that regulates the concentration of specific ions (like Na⁺, K⁺) within a cell, functioning against the concentration gradient using energy.

• Exocytosis:

  • An active process where vesicles formed from the Golgi apparatus or endoplasmic reticulum fuse with the plasma membrane, releasing their contents outside the cell.

• Pinocytosis:

  • A type of active endocytosis, where the plasma membrane engulfs extracellular fluid, forming vesicles that bring fluid into the cell.

• Phagocytosis:

  • An active endocytosis process involving the engulfment of solid particles by the plasma membrane, creating a vacuole for digestion.

• Receptor-Mediated Endocytosis:

  • An active process where specific proteins with receptor sites interact with extracellular substances, allowing selective uptake via membrane invagination.