Pre-ap bio passive and active transport

Passive transport

when dissolved molecules move across a membrane going down the concentration gradient going from [high] to [low]. This process doesn't need energy

Active transport

when dissolved molecules move across the membrane against the concentration gradient going from [low] to [high]. This process requires energy.

diffusion

the movement of particles (usually small) from [high] to [low] through a selectively permeable membrane until it reaches equilibrium, Part of passive transport

Osmosis

the movement of water across the membrane from [high] to [low], part of passive transport

facilitated diffusion

a protein channel used to help larger particles that usually cannot diffuse on their own though the Semipermeable (selective) membrane going from [high] to [low], part of passive transport

endocytosis

the movement of large particles into the cell; a form of active transport

exocytosis

the movement of large particles out of the cell; a form active transport

pinocytosis

a process by which the cell takes in the fluids along with dissolved small molecules, means “to drink” (part of endocytosis)

phagocytosis

a process by which the cell takes in larger substances, means “to eat” ( part of endocytosis)

Hypertonic Solution

Water leaves the cell, so it shrinks. Water flows out of the cell (high solute outside the cell, high water inside the cell)

Hypotonic Solution

Water enters the cell, so it swells and burst. Water flows into the cell. (high water outside the cell, high solute inside the cell)

Isotonic Solution

Water and Solute is the same inside and outside the cell, so the size of the cell stays the same.

The Sodium-Potassium pump

moves Na and K ions in opposite directions, each against its concentration gradient moving from [low] to [high]. 3 Na ions are extruded from and 2 K ions are imported into the cell.