Membrane Structure and Transport Vocabulary

Flashcards covering key vocabulary and concepts related to membrane structure and transport.

Lipid Bilayers

Phospholipids naturally form continuous sheet-like bilayers in water.

Cell Membrane Function

The primary function of the cell membrane is to act as a barrier.

Hydrophobic Core

The hydrophobic core of a lipid bilayer forms a barrier to hydrophilic particles.

Hydrophilic

Attracted to water.

Hydrophobic

Repelled by water.

Amphipathic

Having both hydrophilic and hydrophobic regions.

Fluid Mosaic Model

A model describing the structure of cell membranes as a dynamic arrangement of phospholipids, proteins, carbohydrates, and cholesterol.

Saturated Fatty Acids

Fatty acids with single bonds, leading to lower fluidity.

Unsaturated Fatty Acids

Fatty acids with double bonds, leading to higher fluidity.

Cholesterol

A modulator of membrane fluidity in animal cells.

Vesicles

Small structures within a cell, consisting of fluid enclosed by a lipid bilayer.

Endocytosis

The formation of a vesicle to bring materials into the cell.

Exocytosis

The release of materials from cells via vesicles.

Integral Proteins

Proteins embedded within the cell membrane.

Peripheral Proteins

Proteins on the membrane surface or anchored to an integral protein.

Simple Diffusion

Movement of molecules across a membrane from high to low concentration.

Osmosis

Movement of water molecules across membranes based on solute concentration.

Aquaporins

Proteins that facilitate the movement of water across cell membranes.

Selective Permeability

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

Facilitated Diffusion

The process of spontaneous passive transport of molecules or ions across a biological membrane via specific transmembrane integral proteins.

Channel Proteins

Proteins that provide a channel for facilitated diffusion of specific molecules or ions across a membrane.

Active Transport

The movement of ions or molecules across a cell membrane into a region of higher concentration, assisted by enzymes and requiring energy (ATP).

Pump Proteins

Proteins that actively transport molecules across the cell membrane, often using ATP.

Cotransporters

Proteins involved in indirect active transport, moving multiple molecules across the membrane at once.

Cell Adhesion Molecules (CAMs)

Molecules involved in the adhesion of cells to form tissues.

Exchange Transporters

Proteins that transport one molecule across the membrane in exchange for another.

Sodium-Potassium Pump

An exchange transporter that pumps sodium ions out of the cell and potassium ions into the cell.

Voltage-Gated Channels

Ion channels that open or close in response to changes in membrane potential.

Ligand-Gated Channels

Ion channels that open or close in response to the binding of a specific ligand or neurotransmitter.