Cell Membrane Transport

Flashcards reviewing key concepts of cell membrane transport, including passive transport, active transport, simple diffusion, facilitated diffusion, and reverse osmosis.

Passive Transport

Movement from high to low concentration, no energy required, driven by concentration gradients.

Active Transport

Movement from low to high concentration, requires energy (ATP), enables uptake against gradients.

Bulk Transport

Movement independent of concentration gradients, requires energy, includes endocytosis and exocytosis.

Passive Transport Characteristics

Movement from high to low concentration along the concentration gradient, no energy required, occurs until equilibrium is reached.

Simple Diffusion

Occurs without help from proteins, molecules move freely through the phospholipid bilayer, limited to small, nonpolar molecules.

Facilitated Diffusion

Involves specific membrane proteins, allows transport of molecules that cannot pass readily through the lipid bilayer.

Reverse Osmosis

A semipermeable membrane separates salty/polluted water from pure water, pressure is applied to the salty side to force water the other way against the natural osmotic flow.

Active Transport Definition

Movement of molecules against their concentration gradient (low to high concentration), requires energy, usually in the form of ATP.

Active Transport Characteristics

Not passive energy input is necessary, involves specific transport proteins in the membrane, maintains essential concentration gradients in the cell.