[27] Biochemistry of Digestion Flashcards
What is the primary function of the digestive system?
To break down food into nutrients, which the body uses for energy, growth, and cell repair.
What is digestion?
The process by which food is broken down into smaller components that can be absorbed by the body.
What are the main stages of digestion?
- Ingestion
- Digestion
- Absorption
- Elimination
What is mechanical digestion?
The physical breakdown of large pieces of food into smaller pieces.
What is chemical digestion?
The enzymatic breakdown of food into absorbable components.
What is the role of the mouth in digestion?
The mouth begins digestion by physically breaking down food via mastication and chemically breaking it down via salivary enzymes.
What are the major salivary enzymes and their functions?
- Amylase → Breaks down starch into simple sugars
- Lipase → Begins the breakdown of fat
What is the function of the stomach in digestion?
The stomach secretes acid and enzymes that digest food.
What are the major gastric enzymes and their functions?
- Pepsin → Breaks down proteins into smaller peptides
- Gastric lipase → Helps digest fat
What is the function of the small intestine in digestion?
The small intestine completes the digestion process and absorbs most of the nutrients.
What are the major enzymes secreted by the pancreas and their functions?
- Proteases → Break down proteins
- Amylase → Continues starch digestion
- Lipases → Complete fat digestion
What is the role of bile in digestion?
Bile, produced by the liver and stored in the gallbladder, emulsifies fats to aid in their digestion.
What is the role of the large intestine in digestion?
The large intestine absorbs water and electrolytes, forms and stores feces, and houses gut bacteria that contribute to digestion.
What is cellulose?
A complex carbohydrate, found in plant cell walls, that humans cannot digest.
What is the role of gut bacteria in digestion?
Gut bacteria contribute to digestion by breaking down some substances that human enzymes cannot, such as cellulose and certain sugars and proteins.
