Essential Concepts of Human Digestion and Metabolism

Enzyme Function and Segregation

1. What is the function of amylase? What is the function of pepsin? Why are they segregated?

• Amylase: Amylase begins the digestive process by breaking down starch when you chew your food, converting it into a smaller carbohydrate.
• Pepsin: Pepsin helps digest the proteins in food.

They are segregated because amylase functions primarily in the mouth (saliva), while pepsin functions in the highly acidic environment of the stomach.

Essential Digestive Terminology

2. Definitions:

• Chyme: Is the semi-fluid mass of partly digested food that is expelled by the stomach.
• Intestinal Flora: Is the symbiotic bacteria occurring naturally in the gut.
• Defecation: Is the final action of digestion, by which organisms eliminate solid, semi-solid, or liquid waste material from the digestive tract via the anus.
• Mechanical Digestion: This is the enzymatic breakdown of large, complex molecules found in food into smaller, simpler, more soluble nutrient molecules.

Macronutrients and Essential Molecules

3. Nutritional Components:

Carbohydrates

Glucose is a simple sugar or monosaccharide, one that cannot be broken down into smaller carbohydrates. Complex carbohydrates are substances that are the product of assembling or connecting many smaller molecules, for example, glucose.

Lipids (Fats and Cholesterol)

Fats can be broken down into simpler molecules, namely glycerol and fatty acids.

Types of Fats

• Unsaturated Fats: Of plant origin. They are liquid at room temperature and are referred to as oils.
• Saturated Fats: Such as butter, usually of animal origin. Solid at room temperature.

Proteins

Proteins, such as hemoglobin, are macromolecules formed by the union of hundreds of smaller molecules called amino acids.

Vitamins

Although our bodies only need very small quantities of these organic molecules, they are essential for proper function. As most vitamins are compounds that our bodies cannot synthesize, we must obtain them from our diet.

Basal Metabolism (BMR)

4. Basal Metabolism: Is the number of calories required to keep your body functioning at rest. BMR is also known as your body’s metabolism. Any increase to your metabolic weight, such as exercise, will increase your BMR. To get your BMR, simply input your height, gender, age, and weight below.