B2 - Organisation Flashcards
What’s the main function of the digestive system?
To digest food and absorb nutrients
What’s the role of the pancreas and the salivary gland in the digestive system?
They produce digestive juices containing enzymes
What’s the role of the stomach in the digestive system?
It produces hydrochloric acid killing the bacteria present and provides the optimum acidic pH for the protease enzyme to function
What’s the role of the small intestine in the digestive system?
Soluble food molecules are absorbed into the bloodstream at the small intestine
What’s the role of the liver in the digestive system?
It produces bile (stored in the gallbladder) which breaks down lipids and allows lipase enzymes to work more efficiently
What’s the role of the large intestine in the digestive system?
Absorbs water from undigested food producing faeces(poo)
What’s the role of enzymes in the digestive system?
Enzymes act as biological catalysts and they speed up the breakdown of food
How does the shape of an enzyme affect its function?
Enzymes have a specific active site which is complimentary (combine) to the substrate.
What is metabolism?
The sum of all the reactions in an organism
What types of metabolic reactions to enzymes catalyse?
- Building larger molecules from smaller molecules
- Changing one molecule to another
- Breaking down larger molecules into smaller molecules
How does temperature affect enzyme action?
Increase in the temperature increases enzyme action, because molecules have a higher kinetic energy. Optimum temp = 37 degrees, Going above this temperature will mean that the enzyme begins to denature
How does pH affect enzyme function?
optimum pH = 7 (apart from protease in stomach) . If the pH is too extreme, the shape of the active site may be altered and the enzyme may no longer work
Where are carbohydrases, proteases and lipases produced in the body?
- Carbohydrases: amylase in the salivary gland and pancreas;; maltase in the small intestine
- Proteases: pepsin in the stomach
- Lipases: pancreas and small intestine
What’s the role of proteases in the digestive system?
They break down proteins into amino acids
What does amylase (carbohydrase) break down?
Starch (carbohydrate)
