Topic 4 - Digestion Flashcards
What is the digestive system?
The digestive system is an example of an organ system in which several organs work together to digest and absorb food.
What are enzymes?
Enzymes are biological catalysts that speed up chemical reactions in living organisms. They are large proteins that catalyze a specific reaction due to the shape of the active site being complementary to the shape of one specific substrate.
Why are enzymes denatured?
Enzymes are denatured by high temperature and extremes of pH due to changes in the shape of the active site. They have an optimum temperature and an optimum pH.
What is the ‘lock and key theory’?
The ‘lock and key theory’ model of enzyme action explains how enzymes work. The substrate fits into the active site of the enzyme like a key in a lock.
What do digestive enzymes do?
Digestive enzymes convert large food molecules into small soluble molecules that can be absorbed into the bloodstream.
What is amylase, protease and lipase?
Amylase is a carbohydrase which breaks down starch into glucose. Proteases break down proteins to amino acids. Lipases break down lipids (fats) to glycerol and fatty acids.
What do carbohydrases do?
Carbohydrases digest carbohydrates to simple sugars.
