Passive Transport

Definition

Passive transport is a process by which substances move across cell membranes without the need for energy input from the cell. It relies on the natural movement from areas of high concentration to areas of low concentration.

Scientific / Technical Definition

Passive transport is a type of cellular transport where molecules, such as ions and small molecules, pass through membranes via concentration gradients, without the requirement of cellular energy (ATP). This process includes diffusion, osmosis, and facilitated diffusion.

Benefits

• Helps maintain cellular homeostasis by allowing the movement of substances into and out of cells
• Regulates fluid and electrolyte balance in the body
• Facilitates the absorption of nutrients and expulsion of wastes at a cellular level

Examples

• The diffusion of oxygen from the lungs into the bloodstream
• Osmosis of water into plant roots
• Facilitated diffusion of glucose into cells

Additional Information

• importance: Passive transport is important for keeping a stable internal environment within cells and tissues, essential for the survival and function of living organisms.

Related Terms

• Osmosis
• Diffusion
• Facilitated Diffusion
• Active Transport
• Concentration Gradient

References

• Biochemistry - Concepts and Connections
• Cell Membranes