Membrana de Transporte Biológico

Membrane Transport

Passive Transport

• Movement of molecules from high concentration to low concentration without energy expenditure
• Types:
  • Diffusion: random movement of molecules from high to low concentration
  • Osmosis: movement of water molecules from high to low concentration through a selectively permeable membrane

Active Transport

• Movement of molecules from low concentration to high concentration using energy (ATP)
• Types:
  • Primary active transport: uses ATP to pump molecules across the membrane
  • Secondary active transport: uses energy from other sources (e.g. ion gradients) to transport molecules

Facilitated Diffusion

• Passive transport of molecules through transport proteins in the membrane
• Types:
  • Channel proteins: form a channel for molecules to pass through
  • Carrier proteins: bind to molecules and change shape to transport them across the membrane

Osmosis

• Movement of water molecules through a selectively permeable membrane
• Types:
  • Isotonic: equal concentration of solutes on both sides of the membrane
  • Hypotonic: lower concentration of solutes on one side of the membrane
  • Hypertonic: higher concentration of solutes on one side of the membrane

Transport of Macromolecules

• Large molecules (e.g. proteins, carbohydrates) are transported through the membrane using:
  • Endocytosis: engulfing of molecules by the cell membrane
  • Exocytosis: release of molecules from the cell through the membrane
  • Receptor-mediated transport: specific binding of molecules to receptors on the membrane, followed by transport into the cell

Aprenda sobre os diferentes tipos de transporte de membrana, incluindo transporte passivo, transporte ativo, difusão facilitada, osmose e transporte de macromoléculas.