Nutrition and Organisms

Study Notes

Nutrition is the process by which an organism uses food to support its life, providing energy and chemical structures.
Failure to obtain the required amount of nutrients causes malnutrition.

Nutrients are substances that provide energy and physical components to the organism, allowing it to survive, grow, and reproduce.
Approximately 30 elements are found in organic matter, with nitrogen, carbon, and phosphorus being the most important.
Macronutrients are the primary substances required by an organism, and micronutrients are substances required by an organism in trace amounts.
Organic micronutrients are classified as vitamins, and inorganic micronutrients are classified as minerals.

Organisms can be classified by how they obtain carbon and energy.
Heterotrophs obtain nutrients by consuming the carbon of other organisms.
Autotrophs produce their own nutrients from the carbon of inorganic substances like carbon dioxide.
Mixotrophs can be heterotrophs and autotrophs, including some plankton and carnivorous plants.
Phototrophs obtain energy from light, while chemotrophs obtain energy by consuming chemical energy from matter.
Organotrophs consume other organisms to obtain electrons, while lithotrophs obtain electrons from inorganic substances.
Prototrophs can create essential nutrients from other compounds, while auxotrophs must consume preexisting nutrients.

Scientific analysis of food and nutrients began during the chemical revolution in the late 18th century.
The first vitamin to be chemically identified was thiamine in 1926, and vitamin C was identified as a protection against scurvy in 1932.
Modern nutrition science began in the 1910s as individual micronutrients began to be identified.
The first recommended dietary allowances for humans were developed to address fears of disease caused by food deficiencies during the Great Depression and the Second World War.