Assimilation (from similis, lat. = similar), in biology, designates the process of the transformation of external substances and materials into substances and materials internal to the body. Examples of assimilation are:

• By mean of photosynthesis, carbon dioxide and water are transformed into a number of organic molecules in plant cells.
• Nitrogen fixation from the soil into organic molecules by symbiotic bacteria which live in the roots of certain plants, such as Leguminosae.
• The absorption of nutrients into the body after digestion in the intestine and its transformation in biological tissues and fluids

Related topics

• Anabolism
• Biochemistry