Cell Membrane, Diffusion, and Transport Concepts

Flashcards covering key vocabulary related to cell membranes, transport processes, and diffusion.

Cell Membrane

A thin flexible barrier that surrounds all cells, regulating what enters and exits the cell.

Phospholipid Bilayer

A double layer of phospholipids that constitutes the fundamental structure of a cell membrane.

Hydrophilic Head

The water-attracting part of a phospholipid, which contains a phosphate group.

Hydrophobic Tails

The water-repelling fatty acid tails of phospholipids in the cell membrane.

Diffusion

The movement of particles from an area of high concentration to an area of low concentration.

Osmosis

The diffusion of water across a selectively permeable membrane.

Isotonic Solution

A solution where the concentration of solutes is equal on both sides of a membrane.

Hypertonic Solution

A solution with a higher concentration of solutes compared to another solution.

Hypotonic Solution

A solution with a lower concentration of solutes compared to another solution.

Facilitated Diffusion

A process where molecules that are too large use protein channels to cross the cell membrane without expending energy.

Active Transport

The movement of substances against their concentration gradient, requiring energy from the cell.

Endocytosis

The process of taking in large molecules into the cell by engulfing them.

Exocytosis

The process of moving large molecules out of the cell.