Cellular Transport Quiz Series

The process in which particles spread out from each other

Substances must be dissolved

Gas exchange in the lungs

Alveoli in the lungs

The direction along the concentration gradient and the type of substance being exchanged

Diffusion is the process in which particles spread out from each other, moving from high concentration to low concentration until they are evenly distributed. Examples include gas exchange in the lungs, such as oxygen moving from the alveoli into the blood, and carbon dioxide from the blood into the alveoli, as well as carbon dioxide moving from the air into the leaves of plants and how digested foods like amino acids move from the small intestine into the blood.

The cell membrane allows substances to pass into or out of cells across it, provided the substances are dissolved and there is a concentration gradient for them to move from high concentration to low concentration. The cell membrane facilitates the process of diffusion.

Specialized exchange surfaces, such as the alveoli in the lungs, root hairs in plants, and nephrons in kidneys, provide increased surface area and specific structures to enhance the exchange of materials between cells and their environment, making the exchange as efficient as possible.

The three methods of transport involved in the movement of substances are diffusion, osmosis, and active transport. They differ based on the movement of particles from high to low concentration (diffusion), the movement of water across a selectively permeable membrane (osmosis), and the movement of substances against the concentration gradient requiring energy (active transport).

Diffusion is utilized in gas exchange in the lungs, movement of carbon dioxide into the leaves of plants, and the transport of digested foods like amino acids from the small intestine into the blood. These are all examples of natural processes where diffusion plays a crucial role in the movement of substances.