The Digestive Process and Enzyme Action

Digestive System

• The process of breaking down food into smaller molecules is called digestion.
• The main function of the digestive system is to break down food into smaller molecules that can be absorbed and utilized by the body.

Organization Levels

• The most basic unit of life is the cell.
• The level of organization that involves interaction between tissues and response to the environment is the organ level.

Circulatory and Respiratory Systems

• The main function of the circulatory system is to transport oxygen and nutrients to cells and remove waste products.
• The primary function of the respiratory system is to bring oxygen into the body and remove carbon dioxide.

Digestion and Absorption

• The stomach stores food, breaks it down mechanically and chemically, and empties partially broken down food into the small intestine.
• Most of the digestion of food components occurs in the small intestine.
• The main function of the large intestine is to absorb water and electrolytes, and store and eliminate waste.

Nutrient Absorption and Immune System

• The liver is the first stop for most absorbed nutrients.
• The main fuel for the human brain is glucose.
• A deficiency in protein can increase the risk of infection and death.
• The leading cause of immune system deficiency worldwide is HIV/AIDS.
• The system that regulates appetite, nutrient absorption, and storage is the endocrine system.
• When the digestive system is compromised, nutrient absorption is impaired.