BIO120 - Cell Membrane & Transport

A collection of vocabulary flashcards covering key terms and concepts related to cell membranes and transport mechanisms.

Plasma Membrane

The boundary that separates the living cell from its non-living surroundings.

Selective Permeability

The property of a membrane that allows some substances to cross it more easily than others.

Phospholipid Bilayer

A double layer of phospholipids that forms the structural foundation of cell membranes.

Amphipathic Molecules

Molecules that contain both hydrophobic and hydrophilic regions.

Fluid Mosaic Model

A model describing the cell membrane as a fluid structure with a mosaic of various proteins embedded in it.

Cholesterol

A type of lipid that helps to maintain membrane fluidity at varying temperatures.

Integral Proteins

Proteins that are embedded in the lipid bilayer and span the membrane.

Peripheral Proteins

Proteins that are not embedded but associate loosely with the membrane.

Active Transport

Transport that requires energy, moving substances against their concentration gradient.

Passive Transport

Transport that does not require energy, moving substances down their concentration gradient.

Diffusion

The tendency for molecules to spread out evenly into the available space.

Osmosis

The diffusion of water across a selectively permeable membrane.

Hypertonic Solution

A solution with a higher solute concentration than that inside the cell, causing the cell to lose water.

Hypotonic Solution

A solution with a lower solute concentration than that inside the cell, causing the cell to gain water.

Isotonic Solution

A solution with the same solute concentration as that inside the cell, resulting in no net water movement.

Facilitated Diffusion

Passive transport aided by transport proteins, allowing specific molecules to cross the membrane.

Exocytosis

The process of transporting materials out of the cell via vesicles that fuse with the plasma membrane.

Endocytosis

The process where the cell takes in macromolecules by forming vesicles from the plasma membrane.

Phagocytosis

A form of endocytosis in which the cell engulfs large particles or cells.

Pinocytosis

A form of endocytosis in which the cell ingests extracellular fluid and small particles.

Receptor-Mediated Endocytosis

Endocytosis triggered by the binding of ligands to specific receptors on the cell membrane.

Transport Proteins

Proteins that assist in the movement of substances across the cell membrane.