3: Cell Membrane Structure and Function

Vocabulary flashcards covering key concepts related to cell membrane structure and function, transport mechanisms, and cell junctions.

Plasmodesmata

Channels between plant cells.

Tight junctions

Seal cells together.

Desmosomes

Anchor cells via intermediate filaments.

Gap junctions

Allow communication via ion/molecule transfer.

Plasma Membrane

A phospholipid bilayer with embedded proteins; regulates transport and communication.

Fluid Mosaic Model

Describes the membrane as a dynamic mix of lipids and proteins that move fluidly.

Aquaporins

Channel proteins that facilitate rapid water transport across membranes.

Sodium-Potassium Pump

Active transport protein that moves 3 Na+ out and 2 K+ into the cell, maintaining electrochemical gradients.

Diffusion

Movement of molecules from high to low concentration.

Osmosis

Diffusion of water across a membrane.

Passive transport

Transport that requires no energy.

Active transport

Transport that requires energy (ATP).

Hypotonic

Solution where the cell swells as water enters.

Isotonic

Solution where there is no net movement of water.

Hypertonic

Solution where the cell shrinks as water exits.

Pinocytosis

Cell drinking; uptake of fluids.

Phagocytosis

Cell eating; uptake of large particles.

Receptor-mediated endocytosis

Specific uptake of molecules via receptors.