BIOL 1107K - Cell Membrane Vocabulary

Vocabulary practice flashcards covering cell membrane composition, fluidity factors (phospholipids, temperature, cholesterol), the fluid mosaic model, and types of membrane proteins.

Cell Membrane

A physical barrier that separates internal components (cytoplasm) from the extracellular space, controls movement of ions, nutrients, and waste in and out of the cell, and provides structural support to help maintain shape.

Membrane Fluidity

The flexibility and movement characteristic of cell membranes, influenced by phospholipid structure, temperature, and cholesterol.

Unsaturated Phospholipids

Phospholipids with kinks in their hydrocarbon tails that prevent tight packing, making the membrane loosely packed and increasing fluidity and permeability.

Saturated Phospholipids

Phospholipids with straight hydrocarbon tails that allow them to pack tightly together, making the membrane structure more rigid and decreasing fluidity.

Van der Waals Interactions (Membrane)

Interactions between the hydrophobic tails of phospholipids that prevent them from completely separating at high temperatures.

Cholesterol

An essential amphipathic lipid component embedded in the cell membrane whose hydrophobic region forms van der Waals interactions with phospholipid tails.

Membrane Fluidity Buffer

The stabilizing action of cholesterol in the cell membrane: at low temperatures it forces phospholipids farther apart to increase fluidity, while at high temperatures it attracts phospholipids to decrease fluidity.

Fluid Mosaic Model

A structural model describing the cell membrane as 'fluid' (components can migrate) and a 'mosaic' (composed of phospholipids, cholesterol, and proteins).

Integral Proteins

Proteins that are permanently embedded in the plasma membrane and span its entire width.

Peripheral Proteins

Proteins that are attached to the surface of the cell membrane rather than spanning the hydrophobic core.

Amphipathic Integral Protein

A membrane-spanning protein with hydrophilic regions that interact with intracellular/extracellular aqueous environments and hydrophobic regions that interact with phospholipid tails.

Membrane Protein Functions

The essential biological roles carried out by membrane proteins, including transport, enzymatic activity, signal transduction, cell-cell recognition, intercellular joining, and attachment.

Glycoprotein

A membrane protein covalently attached to a carbohydrate chain on the extracellular side, functioning in processes like cell-cell recognition.

Glycolipid

A phospholipid covalently attached to a carbohydrate chain located on the extracellular surface of the plasma membrane.