Unit 2 Study Guide: Plasma Membrane

Vocabulary flashcards covering the structure, lipid composition, and membrane proteins detailed in the Unit 2 Study Guide.

Plasma Membrane

An active barrier separating Intracellular Fluid (ICF) from Extracellular Fluid (ECF) that controls what enters and leaves the cell.

Intracellular Fluid (ICF)

The fluid located inside the cell, separated from Extracellular Fluid (ECF) by the plasma membrane.

Extracellular Fluid (ECF)

The fluid located outside the cell, separated from Intracellular Fluid (ICF) by the plasma membrane.

Lipid Bilayer

A flexible double layer of lipids that forms the core structure of the plasma membrane.

Glycocalyx

A surface coat on the plasma membrane formed by surface sugars.

Cell Junctions

Structures that help hold cells together.

Phospholipids

Membrane lipids that make up 75% of the lipid bilayer, consisting of polar/hydrophilic phosphate heads and nonpolar/hydrophobic fatty acid tails.

Phosphate Heads

The polar and hydrophilic component of membrane phospholipids.

Fatty Acid Tails

The nonpolar and hydrophobic component of membrane phospholipids.

Glycolipids

Membrane lipids consisting of lipids with attached sugar groups, making up 5% of membrane lipids.

Cholesterol

A lipid component comprising 20% of membrane lipids that increases membrane stability.

Integral Proteins

Membrane proteins firmly inserted into the membrane that function as channels, enzymes, or receptors.

Transmembrane Proteins

Integral proteins that span the whole length of the plasma membrane.

Peripheral Proteins

Membrane proteins that are loosely attached to the membrane and function in cell-to-cell connections.