Term | Definition |
Autotroph | an organism that is able to form nutritional organic substances from simple inorganic substances such as carbon dioxide. |
Heterotroph | an organism deriving its nutritional requirements from complex organic substances. |
Chemoautotroph | an organism, typically a bacterium, that derives energy from the oxidation of inorganic compounds. |
Photoautotroph | any organism that derives its energy for food synthesis from light and is capable of using carbon dioxide as its principal source of carbon |
Calories | either of two units of heat energy. |
Energy | the strength and vitality required for sustained physical or mental activity |
Ingestion | the process of taking food, drink, or another substance into the body by swallowing or absorbing it. |
Digestion | the process of breaking down food by mechanical and enzymatic action in the alimentary canal into substances that can be used by the body. |
Egestion | is the discharge or expulsion of undigested material (food) from a cell in case of unicellular organisms, and from the digestive tract via the anus in case of multicellular organisms. |
Roughage | fibrous indigestible material in vegetable foodstuffs that aids the passage of food and waste products through the gut. |
Cellulose | an insoluble substance that is the main constituent of plant cell walls and of vegetable fibers such as cotton. It is a polysaccharide consisting of chains of glucose monomers. |
Body mass index | a weight-to-height ratio, calculated by dividing one's weight in kilograms by the square of one's height in meters and used as an indicator of obesity and underweight. |
Absorption | the process or action by which one thing absorbs or is absorbed by another. |
Diffusion | the spreading of something more widely. |
Villi | any of numerous minute elongated projections set closely together on a surface, typically increasing its surface area for the absorption of substances, in particular. |
Constipation | a condition in which there is difficulty in emptying the bowels, usually associated with hardened feces. |
Enzyme | a substance produced by a living organism that acts as a catalyst to bring about a specific biochemical reaction. |
Macromolecules | a molecule containing a very large number of atoms, such as a protein, nucleic acid, or synthetic polymer. |
Bulimia | an emotional disorder involving distortion of body image and an obsessive desire to lose weight, in which bouts of extreme overeating are followed by depression and self-induced vomiting, purging, or fasting. |
Anorexia | a lack or loss of appetite for food (as a medical condition). |