Cell membrane and transport

Selective Permeability: The ability of a cell membrane to allow some substances to pass through while blocking others.

Diffusion: The movement of particles from an area of high concentration to an area of low concentration.

Osmosis: The diffusion of water across a selectively permeable membrane.

Passive Transport: The movement of substances across a membrane without using energy.

Concentration Gradient: The difference in concentration of a substance between two areas.

Tonicity: How a solution affects the movement of water into or out of a cell.

Isotonic: A solution with the same concentration of solutes as the inside of a cell, resulting in no net water movement.

Hypertonic: A solution with a higher concentration of solutes than the inside of a cell, causing water to leave the cell.

Hypotonic: A solution with a lower concentration of solutes than the inside of a cell, causing water to enter the cell.

Osmoregulation: The process by which cells or organisms regulate water and solute levels to maintain balance.

Plasmolysis: The shrinking of a plant cell's cytoplasm due to water loss when in a hypertonic solution.

Turgid: A plant cell that is swollen with water, providing firmness.

Flaccid: A plant cell that has lost water and becomes limp.

Facilitated Diffusion: The movement of substances across a membrane through protein channels without energy use.

Ion Channels: Proteins in the cell membrane that allow specific ions to pass through.

Gated Channels: Ion channels that open or close in response to specific signals.

Active Transport: The movement of substances across a membrane using energy (ATP), often against a concentration gradient.

Sodium-Potassium Pump: A protein that uses energy to pump sodium out of the cell and potassium into the cell.

Exocytosis: The process of moving large substances out of a cell by enclosing them in a vesicle.

Endocytosis: The process of bringing large substances into a cell by engulfing them in a vesicle.

Phagocytosis: A type of endocytosis where the cell engulfs large particles or cells.

Pinocytosis: A type of endocytosis where the cell takes in fluids and dissolved substances.