Nutrition, Metabolism, and Energy Balance Glossary

This set of flashcards contains key terms and definitions related to nutrition, metabolism, and energy balance, covering macronutrients, micronutrients, metabolic pathways, and energy regulation.

Macronutrients

Nutrients required by the body in large amounts that provide energy and support growth and metabolism.

Micronutrients

Vitamins and minerals required by the body in small amounts that are essential for proper physiological function but do not provide energy.

Carbohydrates

Organic compounds composed of carbon, hydrogen, and oxygen that serve as the body's primary energy source.

Monosaccharides

Simple sugars that cannot be broken down into simpler sugars; the basic units of carbohydrates.

Disaccharides

Carbohydrates composed of two monosaccharide units linked together.

Polysaccharides

Complex carbohydrates composed of long chains of monosaccharide units.

Glucose

A six-carbon monosaccharide that is the primary fuel source for cellular respiration.

Glycogen

A polysaccharide that serves as the storage form of glucose in animals.

Fiber (Dietary Fiber)

Indigestible carbohydrates found in plant foods that promote digestive health.

Proteins

Large macromolecules composed of amino acids linked by peptide bonds.

Amino Acids

Organic molecules that serve as the building blocks of proteins.

Essential Amino Acids

Nine amino acids that cannot be synthesized by the body and must be obtained from dietary sources.

Nonessential Amino Acids

Amino acids that can be synthesized by the body.

Complete Protein

A protein source that contains all nine essential amino acids in adequate amounts.

Incomplete Protein

A protein source that lacks one or more essential amino acids.

Lipids

Hydrophobic organic molecules that serve as energy storage and cell membrane components.

Triglycerides

The most common form of dietary fat, composed of three fatty acids attached to a glycerol backbone.

Fatty Acids

Long hydrocarbon chains that are the building blocks of many lipids.

Saturated Fatty Acids

Fatty acids with no double bonds between carbon atoms.

Unsaturated Fatty Acids

Fatty acids containing one or more double bonds between carbon atoms.

Trans Fats

Unsaturated fats with trans-configuration double bonds, associated with increased cardiovascular disease risk.

Cholesterol

A steroid lipid that is a component of cell membranes.

HDL (High-Density Lipoprotein)

A lipoprotein that transports cholesterol from tissues to the liver for excretion.

LDL (Low-Density Lipoprotein)

A lipoprotein that transports cholesterol from the liver to tissues.

Vitamins

Organic micronutrients required in small amounts for various physiological functions.

Water-Soluble Vitamins

Vitamins that dissolve in water and are not stored in significant amounts.

Fat-Soluble Vitamins

Vitamins that dissolve in fat and can be stored in the body's fatty tissues.

Minerals

Inorganic elements required by the body for various physiological functions.

Macrominerals

Minerals required in amounts greater than 100 mg per day.

Trace Minerals (Microminerals)

Minerals required in amounts less than 100 mg per day.

Nutrient Density

The amount of essential nutrients provided per unit of energy in food.

Empty Calories

Calories from foods that provide energy but little to no essential nutrients.

Recommended Dietary Allowance (RDA)

The average daily nutrient intake level sufficient to meet the requirements of nearly all healthy individuals.

Adequate Intake (AI)

The recommended average daily nutrient intake level when an RDA cannot be determined.

Malnutrition

A condition resulting from an inadequate, excessive, or imbalanced intake of nutrients.

Undernutrition

A form of malnutrition resulting from insufficient intake of energy, protein, or essential nutrients.

Overnutrition

A form of malnutrition resulting from excessive intake of nutrients.

Bioavailability

The proportion of a nutrient that is absorbed from the diet and becomes available for use.

Metabolism

The sum of all chemical reactions occurring in the body that maintain life.

Catabolism

Metabolic pathways that break down complex molecules into simpler ones.

Anabolism

Metabolic pathways that build complex molecules from simpler ones.

ATP (Adenosine Triphosphate)

The primary energy currency of cells.

Cellular Respiration

The metabolic process by which cells break down glucose and other nutrients in the presence of oxygen.

Aerobic Respiration

The complete oxidation of glucose in the presence of oxygen.

Anaerobic Respiration

The incomplete breakdown of glucose without oxygen.

Glycolysis

A metabolic pathway that breaks down one glucose molecule into two pyruvate molecules.

Pyruvate

A three-carbon molecule produced by glycolysis.

Citric Acid Cycle (Krebs Cycle/TCA Cycle)

A series of chemical reactions that oxidize acetyl-CoA.

Electron Transport Chain (ETC)

A series of protein complexes that transfer electrons to oxygen.

Oxidative Phosphorylation

The process of ATP synthesis coupled to the electron transport chain.

Mitochondria

Organelles where aerobic respiration occurs.

Gluconeogenesis

The metabolic pathway that synthesizes glucose from non-carbohydrate precursors.

Glycogenesis

The metabolic pathway that synthesizes glycogen from glucose.

Glycogenolysis

The metabolic pathway that breaks down glycogen into glucose.

Lipogenesis

The process of synthesizing fatty acids and triglycerides.

Lipolysis

The process of breaking down triglycerides into glycerol and fatty acids.

Beta-Oxidation

The metabolic pathway that breaks down fatty acids in the mitochondria.

Ketogenesis

The metabolic process that produces ketone bodies from acetyl-CoA.

Ketone Bodies

Water-soluble molecules produced during fat metabolism.

Ketosis

A metabolic state characterized by elevated levels of ketone bodies in the blood.

Protein Synthesis

The anabolic process of building proteins from amino acids.

Protein Catabolism (Proteolysis)

The breakdown of proteins into amino acids.

Basal Metabolic Rate (BMR)

The rate of energy expenditure at complete rest.

Resting Metabolic Rate (RMR)

The rate of energy expenditure at rest under less stringent conditions than BMR.

Metabolic Rate

The rate at which the body expends energy or burns calories.

Thermic Effect of Food (TEF)

The increase in energy expenditure following food consumption.

Enzyme

A biological catalyst that speeds up chemical reactions.

Coenzyme

An organic molecule that assists enzymes in catalyzing reactions.

Insulin

A hormone that lowers blood glucose levels.

Glucagon

A hormone that raises blood glucose levels.

Blood Glucose Regulation

The process of maintaining blood glucose levels within a narrow range.

Hyperglycemia

Elevated blood glucose levels above normal range.

Hypoglycemia

Abnormally low blood glucose levels.

Metabolic Syndrome

A cluster of conditions that increase the risk of cardiovascular disease.

Energy Balance

The relationship between energy intake and energy expenditure.

Positive Energy Balance

A state where energy intake exceeds energy expenditure.

Negative Energy Balance

A state where energy expenditure exceeds energy intake.

Neutral Energy Balance (Energy Equilibrium)

A state where energy intake equals energy expenditure.

Calorie (kilocalorie, kcal)

A unit of energy measurement.

Energy Density

The amount of energy per unit weight of food.

Total Daily Energy Expenditure (TDEE)

The total number of calories burned in a day.

Physical Activity Energy Expenditure

Energy expended during planned exercise and physical activity.

Non-Exercise Activity Thermogenesis (NEAT)

Energy expended for activities outside of formal exercise.

Caloric Intake

The total amount of energy consumed in a given period.

Energy Deficit

The condition where caloric intake is less than energy expenditure.

Energy Surplus

The condition where caloric intake exceeds energy expenditure.

Set Point Theory

The hypothesis that the body maintains a predetermined weight range.

Adaptive Thermogenesis

Changes in metabolic rate in response to changes in energy intake.

Metabolic Adaptation

The decrease in metabolic rate that occurs during caloric restriction.

Body Composition

The proportion of fat mass and fat-free mass in the body.

Body Mass Index (BMI)

A measure of body weight relative to height.

Lean Body Mass (Fat-Free Mass)

The total mass of the body excluding fat tissue.

Adipose Tissue

Connective tissue composed primarily of fat cells.

White Adipose Tissue (WAT)

The primary form of fat storage in adults.

Brown Adipose Tissue (BAT)

Specialized adipose tissue that generates heat.

Leptin

A hormone produced by adipose tissue that signals energy status.

Ghrelin

A hormone that stimulates appetite.

Satiety

The feeling of fullness and satisfaction after eating.

Hunger

The physiological need or desire for food driven by internal signals.

Appetite

The psychological desire to eat.