Uptake

Uptake is the process of taking in something from the surrounding environment into an organism, cell, or system. The term is used across biology, environmental science, and social sciences to denote absorption, incorporation, or adoption. Uptake can describe the physical movement of substances into an organism, the internalization of molecules by cells, or the acceptance and use of ideas or technologies by people or organizations.

Biological uptake refers to absorbing nutrients, water, gases, or other molecules. In animals, nutrients are taken up in the gut through mechanisms such as passive diffusion, facilitated diffusion, active transport, and endocytosis. Respiratory uptake involves gas exchange in the lungs or gills. In plants, water and mineral ions are taken up by roots via root hairs, with transport through the xylem driven by transpiration; nutrient uptake can be aided by mycorrhizal fungi.

Uptake is influenced by concentration gradients, temperature, pH, membrane transporters, and saturation of transport systems. Many uptake processes follow Michaelis-Menten kinetics when transport is carrier-mediated, showing a rate that rises with substrate concentration and then levels off.

In ecology and earth science, uptake describes the removal of substances from the environment, such as carbon uptake by forests and oceans, or nutrient uptake by soils and biota, affecting ecosystem productivity and carbon cycles.

In social contexts, uptake denotes the adoption or acceptance of innovations, practices, or policies. Factors affecting uptake include perceived usefulness, ease of use, accessibility, social influence, and incentives, and uptake is often described by diffusion or adoption curves.