Biology Lecture Review: Membrane Fluidity and Transport

These flashcards cover key vocabulary and concepts from the lecture notes centered around membrane fluidity, transport mechanisms, and relevant biological processes.

Membrane Fluidity

The viscosity of the lipid bilayer in a cell membrane, influenced by temperature and fatty acid composition.

Amphipathic Molecule

A molecule that has both hydrophilic (water-attracting) and hydrophobic (water-repelling) parts.

Passive Transport

The movement of molecules across a membrance without energy consumption, typically down their concentration gradient.

Facilitated Diffusion

The process of transporting molecules across a membrane through protein channels, down their concentration gradient.

Active Transport

The movement of molecules against their concentration gradient, requiring energy.

Hydrophobic

A property of molecules that repel water; typically nonpolar.

Hydrophilic

A property of molecules that attract water; typically polar.

Cholesterol

A lipid that stabilizes the cell membrane, affecting its fluidity and integrity.

Homeostasis

The process by which organisms maintain a stable internal environment despite external changes.

Transition Temperature

The temperature at which a membrane changes from a fluid state to a more solid state.

Saturated Fatty Acids

Fatty acids with no double bonds between carbon atoms, leading to tighter packing.

Unsaturated Fatty Acids

Fatty acids with one or more double bonds, causing kinks that prevent tight packing.

Dialysis Tubing

A selective permeable membrane used to separate small molecules from larger ones based on size.

Simple Diffusion

The passive movement of molecules from an area of high concentration to an area of low concentration, without the aid of proteins.

Transport Proteins

Proteins that assist in the movement of substances across a cell membrane.

Glucose

A simple sugar that serves as a primary energy source in cells and is transported across membranes.