Chapter 3 Vocabulary: Cells, Membranes, and Homeostasis

Vocabulary practice flashcards based on Chapter 3: Cells, Membranes, and Homeostasis from Biology: How Life Works (4th Edition).

Amphipathic

A molecule that contains both hydrophilic and hydrophobic regions.

Micelle

A spherical structure formed when amphipathic molecules arrange themselves with their hydrophilic regions facing water and their hydrophobic regions facing inward.

Integral Membrane Protein

A membrane protein that is embedded in the lipid bilayer and interacts with its hydrophobic interior.

Peripheral Membrane Protein

A membrane-associated protein that is attached to the membrane surface rather than embedded in the hydrophobic interior of the bilayer.

Transmembrane Protein

An integral membrane protein that extends completely through the lipid bilayer.

Fluid Mosaic Model

A model of membrane structure in which proteins and other molecules are distributed within a fluid phospholipid bilayer.

Facilitated Diffusion

The passive movement of molecules down their concentration gradient through a membrane transport protein rather than directly through the lipid bilayer.

Aquaporin

A membrane channel protein that allows water molecules to move rapidly across a cell membrane.

Osmotic Pressure

Pressure associated with the tendency of water to move across a selectively permeable membrane because of differences in solute concentration.

Primary Active Transport

Movement of substances against their concentration gradient using energy directly from ATP.

Secondary Active Transport

Active transport in which the energy stored in an electrochemical gradient is used to move another substance against its concentration gradient.

Electrochemical Gradient

A gradient across a membrane that contains both a chemical concentration component and an electrical charge component.

Lipid Raft

A specialized region of a cell membrane containing particular lipids and proteins that can function together in cellular processes.

Endomembrane System

An interconnected system of membranes in eukaryotic cells that creates cellular compartments and participates in the synthesis, modification, sorting, and transport of molecules.

Cisternae

Flattened membrane-enclosed compartments that make up structures such as the Golgi apparatus.