Biological Membranes and Transport Mechanisms

This set of flashcards covers key vocabulary and concepts related to biological membranes and transport mechanisms.

Phospholipid bilayer

A structure that allows the movement in and out of the cell, composed of phospholipids with hydrophilic heads and hydrophobic tails.

Fluid mosaic model

A model that describes the cell membrane as a dynamic structure with various proteins embedded in or attached to a phospholipid bilayer.

Intrinsic proteins

Proteins that are embedded within the cell membrane and play roles in transport and signaling.

Extrinsic proteins

Proteins located on the surface of the membrane that may have roles in cell signaling or structural support.

Active transport

The movement of substances against their concentration gradient using energy, often in the form of ATP.

Facilitated diffusion

The passive movement of molecules across the cell membrane via special transport proteins.

Endocytosis

A process where the cell membrane engulfs materials to bring them into the cell, forming vesicles.

Exocytosis

The process of vesicles fusing with the plasma membrane to release their contents outside the cell.

Osmosis

The diffusion of water across a selectively permeable membrane from an area of lower solute concentration to an area of higher solute concentration.

Turgid

A state of a plant cell when it is swollen with water, creating pressure against the cell wall.

Plasmolysis

The process where the cell membrane pulls away from the cell wall due to water loss in a hypertonic solution.

Crenation

The process in which animal cells shrink due to water loss in a hypertonic environment.

Hydrophobic R-groups

Hydrophobic side chains of amino acids that can affect the membrane protein's orientation within the lipid bilayer.