What is the movement of materials through a membrane against a concentration gradient called?

What is the movement of materials through a membrane against a concentration gradient called?

• A. Diffusion
• B. Active Transport
• C. Endocytosis
• D. Exocytosis

Answer: (B)

The movement of materials through a membrane against a concentration gradient is termed active transport. This process involves the use of energy, typically in the form of ATP, to transport substances from an area of lower concentration to an area of higher concentration. Unlike diffusion, which is a passive process that relies on the natural tendency of particles to move from areas of high concentration to low concentration, active transport requires energy input to move substances against this natural flow. Active transport is crucial for various cellular functions, such as maintaining ion concentrations across membranes, nutrient uptake, and waste removal. Examples include the sodium-potassium pump, which actively transports sodium ions out of and potassium ions into the cell, helping to establish a balance necessary for cell function. Understanding this concept is fundamental in cell biology, as it highlights how cells regulate their internal environments to ensure proper functioning, despite external concentration gradients that would otherwise favor passive movements of substances.

The movement of materials through a membrane against a concentration gradient is termed active transport. This process involves the use of energy, typically in the form of ATP, to transport substances from an area of lower concentration to an area of higher concentration. Unlike diffusion, which is a passive process that relies on the natural tendency of particles to move from areas of high concentration to low concentration, active transport requires energy input to move substances against this natural flow.

Active transport is crucial for various cellular functions, such as maintaining ion concentrations across membranes, nutrient uptake, and waste removal. Examples include the sodium-potassium pump, which actively transports sodium ions out of and potassium ions into the cell, helping to establish a balance necessary for cell function.

Understanding this concept is fundamental in cell biology, as it highlights how cells regulate their internal environments to ensure proper functioning, despite external concentration gradients that would otherwise favor passive movements of substances.