apsorpciju

Apsorpciju, commonly translated as absorption, is the process by which a substance is taken up into another material. The term is used across many scientific disciplines to describe the uptake of matter or energy, including light, chemicals, nutrients, drugs, or pollutants.

In physics and chemistry, absorption refers to the capture of energy by a material, resulting in an increase of its internal energy. It is described by absorption spectra and quantified through approaches such as the Beer-Lambert law. Absorbed light is not transmitted or reflected, and the pattern of absorbed wavelengths reveals information about electronic or vibrational transitions within the substance.

In biology and medicine, absorption denotes the uptake of substances across biological membranes. For example, oral drug absorption involves transfer from the gastrointestinal tract into the bloodstream and is influenced by solubility, ionization (pH-dependent), dissolution rate, intestinal surface area, and transit time. First-pass metabolism can further reduce systemic availability. Absorption is a key component of a substance’s bioavailability.

In pharmacology, absorption is evaluated alongside distribution, metabolism, and excretion to understand a drug’s overall behavior in the body. Factors affecting absorption include formulation, particle size, lipophilicity, and interactions with transporters. Experimental models such as Caco-2 cell monolayers and diffusion chambers estimate permeability.

In environmental science, absorption also describes uptake by organisms or materials, and it is distinct from adsorption, which involves surface adhesion. Dermal absorption depends on lipid solubility, skin integrity, and exposure dose, while inhalation and ingestion follow related principles of transfer and rate.

See also: absorption spectrum, bioavailability, permeability, diffusion, adsorption.