Energy Systems (EXS 100)

Vocabulary flashcards covering key terms from the notes on energy metabolism, macronutrients, and energy systems.

Carbohydrates (CHO)

Macronutrient that provides energy; 4 kcal per gram; includes bread, sugars, and fruits; CHO can be stored as glycogen in the body.

Glycogen

Stored carbohydrate in liver and muscle; the body's stored form of CHO.

Starch

Plant storage carbohydrate; breaks down into glucose for energy.

Glucose

Simple sugar and primary energy source for cells; a basic CHO unit.

Anabolism

Biochemical processes that build larger molecules from smaller ones.

Catabolism

Biochemical processes that break down molecules to release energy.

Complete proteins

Proteins that contain all essential amino acids; typically found in meat; do not require combining to meet needs.

Incomplete proteins

Plant-based proteins lacking one or more essential amino acids; require a variety of sources to meet needs.

Protein

Macronutrient that provides 4 kcal/g; essential for tissue repair, enzymes, and hormones.

Calories per gram (Protein)

4 kcal per gram.

Calories per gram (Carbohydrates)

4 kcal per gram.

Calories per gram (Fat)

9 kcal per gram.

Fats (Lipids)

Energy-dense macronutrient; 9 kcal/g; sources include peanut butter, oils, avocado, butter; animal products contain fat.

ATP-PCr system

Immediate energy system that uses phosphocreatine to rapidly regenerate ATP; duration ~0–3 seconds; fuel: ATP available in the moment.

Phosphocreatine (PCr)

High-energy phosphate storage that regenerates ATP during short, intense activity.

Anaerobic energy system

Energy system without oxygen; ~5 seconds to 2 minutes; high-intensity activities; fuel: carbohydrates.

Aerobic energy system

Energy system requiring oxygen; duration >2–3 minutes; moderate-to-low intensity; fuel: carbohydrates and fats.