ABSTRACT
Food is any material that is taken into the human body for the purpose of satisfying hunger, growth, maintenance, tissue repair, reproduction, work, or pleasure. As a general rule, humans must eat other forms of life, their derivatives, or synthetically created versions of these things to subsist. Not all forms of life follow this rule. For example, plants largely exist without consuming other forms of life. They are able to absorb water and minerals from the soil in which they grow. At the same time, nitrogen compounds are also extracted from the soil and utilized in the production of amino acids and proteins. Plants can also harness solar electromagnetic radiation for the synthesis of carbohydrates and also pro duce lipid structures, including a variety of fatty acids. Plants also participate in symbiotic relationships with microorganisms. This can be said for humans and other animals as well. For example, the microflora of the human lower gastrointestinal tract produce small, yet nutritionally significant, quantities of biotin and vitamin K.
