Diffusion and Osmosis Lecture

These flashcards cover the key vocabulary and concepts related to diffusion and osmosis as discussed in the lecture.

Diffusion

The spontaneous movement of molecules in solution from an area of high concentration to an area of low concentration.

Facilitated diffusion

The process of diffusion through pores, channels, or carrier proteins which requires a membrane protein.

Active transport

The movement of molecules through transporters or pumps that requires energy input and a membrane protein.

Osmosis

The spontaneous net movement of solvent molecules, particularly water, through a selectively permeable membrane.

Concentration gradient

The difference in concentration of a substance across a space, creating a gradient that drives diffusion.

Selectively permeable membrane

A membrane that allows only certain molecules to cross, important for maintaining homeostasis in cells.

Hydrophobic

The property of a molecule that does not interact with water and can diffuse through the lipid membrane.

Permeability barrier

The resistance presented by phospholipid head groups against the movement of polar molecules.

Hypertonic solution

A solution with a higher concentration of solute than inside the cell, causing it to shrink.

Hypotonic solution

A solution with a lower concentration of solute than inside the cell, causing it to swell or burst.

Isotonic solution

A solution with equal concentrations of solute, resulting in no net movement of water.

Solvent

A substance that dissolves a solute; in biological systems, this is often water.

Transport protein

A protein that facilitates the transport of certain substances across a cell membrane.

Random thermal motion

The erratic movement of particles in a solution, which contributes to diffusion.

Membrane composition

The structure and makeup of a membrane that influences its function and permeability.