Chapter 4 Nutrition, Metabolism, Enzymes

malnutrition

the medical condition resulting from the lack of any essential nutrient in the diet.

nutrients

components in food that the body needs to grow, develop, and repair itself

energy

the ability to do work, including building complex molecules

macronutrients

nutrients that organisms must ingest in large amounts to maintain health. EX: carbohydrates, proteins, lipids (fats)

essential nutrients

nutrients that cannot be made by the body, so must be obtained from the diet.

starch

a complex plant made of linked chains of glucose molecules; a source of stored energy

essential amino acids

amino acids the human body cannot synthesize and must obtain from food. EX: meat, eggs, fish and dairy

catabolic reaction

any chemical reaction that breaks down complex molecules into simpler molecules

anabolic reaction

any chemical reaction that combines simple molecules to build more-complex molecules

metabolism

all the chemical reactions taking place in the cells of a living organism that allow it to obtain and use energy

enzyme

protein that speeds up a chemical reaction

catalysis

the process of speeding up the rate of a chemical reaction (by enzymes)

substrate

molecule to which an enzyme binds and on which it acts

active site

part of an enzyme that binds to a substrate

activation energy

energy required for a chemical reaction to proceed

mineral

an inorganic chemical element required by organisms of normal growth, reproduction, and tissue maintenance. EX: calcium, iron, potassium, zinc

micronutrients

nutrients, including vitamins and mineral, that organisms must ingest in small amounts to maintain health

vitamin

an organic molecule required in small amounts for normal growth, reproduction, and tissue maintenance

cofactor

an inorganic substance, such as a metal ion, required to activate an enzyme

coenzyme

a small organic molecule, such as a vitamin, required to activate an enzyme