Types of Nutrients: Organic and Macronutrients

Flashcards covering the classification of nutrients, chemical compositions, energy yields, and the functions/properties of carbohydrates, fats, and proteins.

Nutrients

Chemical substances obtained from food and used in the body to provide energy, structural materials, and regulating agents to support growth, maintenance, and repair of the body’s tissues.

Six Classes of Nutrients

The chemical categories of substances used by the body: carbohydrates, lipids, proteins, water, vitamins, and minerals.

Energy-yielding nutrients

The three classes of organic nutrients used by the body to provide energy: carbohydrates, lipids (fats), and proteins.

Macronutrients

Nutrients the body requires in relatively large amounts, measured in grams ($g$) or kilograms ($kg$), which include water, carbohydrates, lipids, and proteins.

Micronutrients

Nutrients required in small amounts, such as vitamins and minerals, with requirements expressed in milligrams ($1\text{mg} = 1/1,000\text{g}$) or micrograms ($1\text{µg} = 1/1,000,000\text{g}$).

Organic nutrients

Nutrients composed of organic molecules containing carbon bonded to hydrogen, including carbohydrates, proteins, lipids, and vitamins.

Inorganic nutrients

Nutrients composed of molecules that do not contain carbon-hydrogen bonds, specifically minerals and water.

Carbohydrate energy yield

The amount of energy produced when a gram of carbohydrate is completely broken down, which is about $4\text{\thinspace kcal}$.

Protein-sparing action

The function of carbohydrates to supply energy needs (requiring at least $50–100\text{\thinspace g/day}$) so that proteins can be used for their primary purpose of building and repairing body tissues.

Monosaccharides

A class of carbohydrates with the chemical formula $C_{6}H_{12}O_{6}$, including examples like glucose, fructose, and galactose.

Disaccharides

Carbohydrate molecules with the formula $C_{12}H_{22}O_{11}$ formed by pairs of monosaccharides: maltose ($\text{glucose} + \text{glucose}$), sucrose ($\text{glucose} + \text{fructose}$), and lactose ($\text{glucose} + \text{galactose}$).

Polysaccharides

Complex carbohydrates with the formula $(C_{6}H_{10}O_{5})_{n}$, including starch, glycogen, cellulose, and pectin.

Ketoacidosis

A metabolic state resulting from a serious carbohydrate deficiency where the liver is depleted of glycogen and builds up ketones in the bloodstream as by-products of fat breakdown.

Fat energy yield

The concentrated energy provided by one gram of fat, which is $9\text{\thinspace calories}$.

Triglycerides

The form of $95\text{\thinspace percent}$ of lipids in the body, composed of a glycerol framework attached to three fatty acid chains.

Essential fatty acids (EFAs)

Necessary polyunsaturated fats that humans cannot synthesize and must obtain via diet, categorized into omega-3 and omega-6 families.

Saturated Fats

Fats containing only single bonds between carbon molecules, usually solid at room temperature, and found in meat, egg yolks, whole milk, and some plant oils like palm and coconut.

Unsaturated fatty acids

Loosely packed fats that are liquid at room temperature and contain one or more double bonds in their carbon chains; they are found in vegetable oils, nuts, and seeds.

Monounsaturated fatty acids (MUFAs)

A type of unsaturated fat with only one double bond, of which oleic acid comprises approximately $90\text{\thinspace percent}$ in the diet.

Hydrogenation

The chemical process of adding hydrogen atoms to unsaturated fats to produce semisolid or solid products, resulting in the creation of trans-fatty acids (TFAs).

Cholesterol

A sterol found in animal foods and body cells (but not plants) used to synthesize bile, sex hormones, cortisone, and vitamin D; the liver produces $800$ to $1,000\text{\thinspace mg}$ daily.

Atherosclerosis

A cardiovascular disease characterized by the formation of plaque (fatty deposits) on artery walls, which can lead to heart attacks or strokes.

Plasticity

The unique property of fats where they melt over a range of temperatures rather than at a fixed point, allowing some to be spreadable at room temperature.

Shortening

A property of fats used in baking to coat flour particles and prevent water absorption, thereby reducing gluten development and creating a crumbly texture.

Complete proteins

Proteins of high biologic value that contain all the essential amino acids, primarily found in animal foods like meat, fish, poultry, eggs, and milk.

Incomplete proteins

Proteins that lack one or more essential amino acids and cannot build tissue alone, typically found in plant foods like grains, nuts, and legumes.

Essential amino acids

The ten amino acids necessary for growth and development that must be provided by the diet: Arginine, Phenylalanine, Histidine, Threonine, Isoleucine, Tryptophan, Leucine, Valine, Lysine, and Methionine.

Protein composition

Like carbohydrates and fats, they contain carbon, hydrogen, and oxygen, but they are the only nutrient group to always contain nitrogen (and sometimes sulfur).

Denaturation

A partially reversible change in the structure of protein molecules caused by heat, salts, pH, or mechanical action, such as whisking egg whites into a foam.

Coagulation

An irreversible change following denaturation where proteins become firmer or set, seen in cooking eggs, making cheese, or thickening sauces.

Gluten

A strong, elastic composite of proteins joined with starch found in wheat flour that forms a 3D network to give bread structure and retain expanding gases.

Gelation

A reversible process where gelatine (derived from collagen) unwinds in warm water and traps liquid upon cooling to form a gel.