Passive Transport Diffusion Definition

This cartoon illustrates passive diffusion.

Passive transport diffusion definition. The movement of substances as by diffusion across a cell membrane without the expenditure of energy compare active transport first known use of passive transport 1953 in the meaning defined above. Diffusion is a passive process of transport. You are familiar with diffusion of substances through the air. Passive transport is a type of cellular transport in which substances such as ion s and molecule s move down their respective concentration gradient s.

This is a spontaneous process and cellular energy is not expended. Passive transport also known as passive diffusion is a process by which an ion or molecule passes through a cell wall via a concentration gradient or from an area of high concentration to an area of low concentration. Passive transport does not require the cell to expend any energy and involves a substance diffusing down its concentration gradient across a membrane. Definition of passive transport.

It is totally opposite to active transport. Passive transport is a movement of ions and other atomic or molecular substances across cell membranes without need of energy input. Substances tend to move towards the region where they are few. For example think about someone opening a bottle of perfume in a room filled with people.

It is also known as passive diffusion which forms a region of high concentration to the region of low concentration. A single substance tends to move from an area of high concentration to an area of low concentration until the concentration is equal across the space. It is a process in which a molecule or ion passes through a cell membrane via a concentration gradient. Unlike active transport it does not require an input of cellular energy because it is instead driven by the tendency of the system to grow in entropy.

What is passive transport. Passive diffusion follows a concentration gradient which relates to the transport of molecules from a location of higher concentration to a site of lower concentration without using chemical energy according to fick s law of diffusion. It means that the substance tends to move from an area of higher concentration to an area of lower concentration. Passive diffusion across a cell membrane.