Nutrition and Organisms

Nutrition

• 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

• 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.

Nutritional Groups

• 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.

History of Nutrition Science

• 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.