Video Notes: Cell Membrane Transport - Vocabulary

Vocabulary flashcards covering cell membrane structure, transport types, gradients, and plant–animal osmosis concepts from the lecture notes.

Active transport

Movement of a substance from low to high concentration, against the gradient, requiring energy (ATP) and transport proteins.

Sodium-potassium pump

Ubiquitous active transport pump exporting 3 Na+ for 2 K+ in per cycle to maintain resting membrane potential and electrochemical gradient.

Electrochemical gradient

Combination of ion concentration gradient and electrical gradient used to drive movement of ions and other solutes.

Bulk transport

Active transport that moves large molecules via vesicles (not through simple diffusion or channels).

Phagocytosis

Endocytosis of solid particles by engulfment with pseudopods, forming a vesicle.

Pinocytosis

Endocytosis of dissolved solutes via vesicles; nonspecific uptake of extracellular fluid.

Receptor-mediated endocytosis

Highly specific uptake requiring binding of a molecule to membrane receptors before endocytosis.

Endocytosis

Process by which cells take in material by engulfment into vesicles from the plasma membrane.

Exocytosis

Vesicles fuse with the plasma membrane to release contents outside the cell.

Diffusion

Passive movement down a concentration gradient; can be simple or facilitated.

Facilitated diffusion

Diffusion through transport proteins (channels or carriers) for substances that cannot diffuse directly.

Osmosis

Diffusion of water across a selectively permeable membrane; no ATP required; driven by solute differences.

Aquaporins

Channel proteins that facilitate rapid water movement across membranes.

Glucose transporters

Membrane proteins that facilitate diffusion of glucose into cells.

Channel proteins

Proteins that form channels allowing ions or molecules to pass through membranes.

Transport proteins

Proteins that move substances across membranes, including channels, carriers, pumps.

Resting membrane potential

Electrical potential difference across the membrane when a cell is at rest; typically negative inside.

Ion channels

Protein channels that allow specific ions to cross the membrane, contributing to membrane potential.

Plant cell turgor pressure

Structural support in plants due to water uptake against cell walls, aiding rigidity and upright growth.

Osmosis in plant roots

Water uptake driven by higher solute concentration in root hair cells relative to soil; essential for root water transport.