Lecture on Metabolism and Nutrients

Composition of the Human Body

Water: 64%
Proteins: 16%
- Present in muscles, neurons (sodium-potassium pumps), blood (hemoglobin), and enzymes.
Fats: 16%
Minerals: 4%
- Includes calcium, phosphorus, iron.
Carbohydrates: 1%
- Consumed for energy or stored as glycogen.

Body constantly acquires, retains, uses, and discards materials.
Lifelong synthesis of protein equates to 225-450 kg.
Metabolism: Series of reactions for converting food into energy and raw materials.

Metabolism encompasses all biochemical reactions in the body.
Two main processes:
- Anabolism: Builds larger molecules, consumes energy.
- Catabolism: Breaks down molecules, releases energy.

Water: Major component of the body.
Vitamins: Fat-soluble and water-soluble, aid in nutrient utilization.
- Examples: Vitamin C (iron absorption), Vitamin K (blood clotting), B vitamins (ATP production).
Minerals: Support structural and functional roles.
- Examples: Calcium, magnesium, phosphorus (bones/teeth), iron (hemoglobin).
Carbohydrates:
- Primarily from plants, converted to glucose.
- Stored as glycogen or triglycerides.
- Essential for ATP production, especially for neurons and red blood cells.
Fats:
- Store energy, vitamins, and cushion organs.
- Found in adipose tissue, myelin, oils, breast milk.
- Cholesterol and phospholipids are vital.
Proteins:
- Comprise muscles, connective tissues, enzymes, and ion channels.
- Consist of 20 amino acids, 9 essential ones must be consumed.

Metabolism is a continuous, complex process of energy and material transformation.
Learning how nutrients function helps understand human biology and energy dynamics.

Information provided by Crash Course team.
- Writer: Kathleen Yale
- Editor: Blake de Pastino; Consultant: Dr. Brandon Jackson
- Director: Nicholas Jenkins; Sound: Michael Aranda; Graphics: Thought Cafe
Supported by Patreon patrons, filmed in the Doctor Cheryl C. Kinney Crash Course Studio.