Plasma Membrane

These flashcards cover key concepts related to the structure and function of the plasma membrane.

Plasma Membrane

The structure that defines the borders of a cell and maintains its functionality.

Selectively Permeable

A property of the plasma membrane that allows certain molecules to pass through while blocking others.

Fluid Mosaic Model

A model describing the plasma membrane as a fluid combination of phospholipids, cholesterol, and proteins.

Phospholipids

Molecules that form the fundamental structure of the plasma membrane, consisting of hydrophobic tails and hydrophilic heads.

Integral Proteins

Proteins that are integrated completely into the membrane structure, interacting with both hydrophilic and hydrophobic regions.

Functions of Membrane Proteins

Includes transport, enzymatic activity, signal transduction, cell-cell recognition, intercellular joining, and attachment to the cytoskeleton and ECM.

Glycoproteins

Proteins that have carbohydrate chains attached, serving important roles in cell recognition.

Glycolipids

Lipids that have carbohydrate chains attached, found on the exterior surface of the plasma membrane.

Membrane Fluidity

The ability of phospholipids and proteins in the plasma membrane to move within the bilayer.

Determinants of Membrane Fluidity

Factors such as temperature, saturation of fatty acid tails, and the presence of cholesterol.

Cholesterol

A molecule that maintains membrane fluidity by restricting movement at high temperatures and preventing packing at low temperatures.

Glycocalyx

The collective term for carbohydrates bound to proteins and lipids on the extracellular surface of the plasma membrane.

Unsaturated Fatty Acids

Fatty acids with one or more double bonds that increase membrane fluidity.

Saturated Fatty Acids

Fatty acids without double bonds that make membranes more viscous.

Fish in Cold Climates Hypothesis

A proposed explanation of how fish plasma membranes resist freezing in extremely cold waters.