Cell Membranes and Transport Mechanisms

A series of vocabulary flashcards covering key concepts related to cell membranes and transport mechanisms in biology.

Fluid-Mosaic Model

A model describing the structure of cell membranes as flexible and composed of various components including phospholipids and proteins.

Phospholipids

Molecules with hydrophilic heads and hydrophobic tails that form the bilayer of cell membranes.

Amphipathic

Describes molecules that have both hydrophilic and hydrophobic parts.

Heterokaryon Experiment

An experiment that demonstrated the mobility of proteins in cell membranes by fusing mouse and human cells.

Membrane Fluidity

The ability of the lipid bilayer to remain flexible, allowing components to move laterally.

Cholesterol

A molecule inserted in the membrane that can decrease or increase fluidity depending on temperature.

Glycoproteins

Proteins that have carbohydrate groups attached, involved in various cellular functions including cell recognition.

Selective Permeability

The property of cell membranes that allows certain substances to pass while restricting others.

Active Transport

The movement of molecules across a membrane from low to high concentration, requiring energy.

Passive Transport

The movement of molecules across a membrane from high to low concentration without energy use.

Facilitated Diffusion

The process in which polar and charged molecules cross membranes with the help of transport proteins.

Osmoregulation

The process of maintaining water balance and osmotic pressure in cells.

Co-Transport

A transport method that moves more than one molecule at a time across a membrane.

Na+/K+ Pump

An active transport mechanism that pumps sodium ions out of the cell and potassium ions into the cell.

Endocytosis

The process of incorporating materials into the cell by forming vesicles from the plasma membrane.

Exocytosis

The process of transporting materials out of the cell via vesicle fusion with the plasma membrane.