Nutrition: Carbohydrates, Lipids, and Proteins

Vocabulary flashcards covering the essential terms, classifications, biochemical processes, and health conditions associated with carbohydrates, lipids, and proteins from Chapters 4, 5, and 6.

Carbohydrates

Essential macronutrients produced by plants through photosynthesis using sunlight, carbon dioxide, and water to create glucose, which fuels human body processes.

Monosaccharides

Simple carbohydrates that consist of a single sugar unit, including glucose, fructose, and galactose.

Disaccharides

Simple carbohydrates consisting of two sugar units joined together, including maltose, lactose, and sucrose.

Polysaccharides

Complex carbohydrates that contain more than $2$ sugar units, such as starch and fiber.

Fructose

The sweetest of all sugars, found abundantly in sweets.

Glycogen

The storage form of glucose in animals, stored in the liver and muscle tissue.

Resistant starch

A type of starch that is not digested in the gastrointestinal (GI) tract.

Soluble fiber

A form of dietary fiber that dissolves in water and is easily fermented by bacteria in the intestine, helping lower cholesterol and blood glucose.

Insoluble fiber

A form of dietary fiber that does not dissolve in water and is not easily fermented by intestinal bacteria, functioning to increase stool bulk and relieve constipation.

Functional fiber

Fiber that has been extracted or isolated from a plant or manufactured by the food industry, which has demonstrated health benefits.

Glycogenesis

The metabolic process of converting excess glucose into glycogen for storage in the liver and muscles.

Glycogenolysis

The metabolic process of breaking down stored glycogen into glucose.

Gluconeogenesis

The metabolic process of generating new glucose from non-carbohydrate sources, such as glucogenic amino acids.

Ketone bodies

By-products of the incomplete breakdown of fat to meet energy needs after about $18\,\text{hours}$ of fasting, which make the blood more acidic once liver glycogen is depleted.

Insulin

A protein hormone produced by the pancreas that acts to lower blood sugar and maintain blood glucose levels within a healthy range.

Glucagon

A pancreatic hormone that works alongside insulin to increase blood glucose levels when they drop, maintaining levels within $70\text{ to }110\,\text{mg/dL}$.

Cortisol

A hormone released from the adrenal glands, known as the stress hormone, which increases blood glucose by stimulating gluconeogenesis and reducing muscle glucose uptake.

Lipogenesis

The metabolic process of fat synthesis in which excess nutrients are converted into glycerol and fatty acids to be stored as triglycerides in adipocytes.

Hypoglycemia

A condition characterized by a blood glucose level $< 70\,\text{mg/dL}$, often resulting from excess insulin production.

Type 1 diabetes

An autoimmune disease accounting for $5\%\text{ to }10\%$ of diabetes cases, in which the immune system destroys pancreatic beta cells, causing an absence of insulin production.

Type 2 diabetes

The most common form of diabetes, making up $90\%\text{ to }95\%$ of cases, characterized by insulin resistance where the pancreas overproduces insulin before decreasing production over time.

Prediabetes

A state of impaired glucose tolerance marked by a fasting blood sugar level between $100\,\text{mg/dL}$ and $126\,\text{mg/dL}$.

Gestational diabetes

A form of diabetes diagnosed during pregnancy with no prior diabetes history, caused by pregnancy-related hormone interference and inadequate insulin secretion.

Lactose intolerance

A deficiency of the enzyme lactase, causing maldigestion of lactose that presents as nausea, cramps, bloating, flatulence, and diarrhea.

Lipids

A category of hydrophobic macronutrients composed of carbon, hydrogen, and oxygen, encompassing triglycerides, phospholipids, and sterols.

Fatty acids

The basic building blocks for triglycerides and phospholipids.

Saturated fatty acids

Fatty acids in which every carbon atom is fully bound to hydrogen atoms with no double bonds, possessing straight chains and remaining solid at room temperature.

Hydrogenation

A food manufacturing process that adds hydrogen atoms to unsaturated liquid oils to improve fatty acid stability and reduce rancidity.

Omega-3 fatty acids

Essential polyunsaturated fatty acids characterized by multiple double bonds in their carbon chains, found as ALA in plants and as EPA and DHA in seafood.

Essential fatty acids

The two polyunsaturated fatty acids that the human body cannot synthesize on its own: linoleic acid and alpha-linolenic acid.

Lecithin

A type of phospholipid commonly used as an emulsifier in foods.

Cholesterol

The best-known sterol found in every animal cell, which serves as a precursor to vitamin D, sex steroids, and adrenal corticoids.

Phytosterols and stanols

Plant-derived compounds found in plant oils, legumes, seeds, and grains that lower blood LDL levels by competing directly with cholesterol for absorption.

Rancidity

The chemical breakdown of fats and oils caused by exposure to oxygen, heat, light, water, or enzymes, leading to stale tastes, foul odors, and reduced nutritional quality.

Lipases

The group of enzymes responsible for the chemical digestion of fats.

CCK (Cholecystokinin)

A hormone that triggers the gallbladder to release bile into the digestive tract for fat digestion.

High-Density Lipoproteins (HDLs)

Lipoproteins produced by the liver that carry out reverse cholesterol transport by collecting excess cholesterol from arterial walls and body cells to take it back to the liver.

Low-Density Lipoproteins (LDLs)

Lipoproteins that transport cholesterol from the liver to tissues; excess oxidized forms can be ingested by macrophages to create foam cells and arterial plaque.

Denaturation

A process that alters the three-dimensional shape of a protein without breaking its primary amino acid sequence, triggered by heat, acids, bases, salts, or mechanical agitation.

Deamination

The metabolic process of removing the amine group from an amino acid, resulting in the production of ammonia.

Albumin

A blood protein synthesized by the liver that plays a critical role in regulating fluid balance in the human body.

Positive nitrogen balance

A physiological state in which nitrogen intake exceeds nitrogen excretion, occurring in growing children, pregnant women, and individuals recovering from injury or surgery.

Negative nitrogen balance

A state in which nitrogen excretion exceeds nitrogen intake, typically seen following acute surgery, during infection, or during severe emotional trauma.

Vegan

A strict vegetarian dietary subgroup that consumes exclusively plant foods and excludes all animal-derived foods such as meat, fish, poultry, eggs, and dairy.