Digestion and absorption Flashcards
Role of the oesophagus?
carries food from the mouth to the stomach
Role of the stomach?
stores and digests food. Has glands which produce enzymes for protein digestion
Role of the ileum (small intestine)?
food is digested by enzymes produced in the walls and glands of the small intestine. Inner walls are folded into villi, with small projections called microvilli which give a large surface area, for rapid absorption into the bloodstream
Role of the large intestine?
absorbs water
Role of the salivary glands?
secrete amylase, which hydrolyses starch into maltose
Role of the pancreas?
secretes pancreatic juice containing protease, lipase and amylase
Why is it necessary to digest polymers?
- need to be small enough to pass into the bloodstream from the small intestine
- need to be soluble for absorption
What are physical and chemical digestion?
physical - large pieces of food are broken down into smaller pieces by physical structures, which increases surface area for chemical digestion
chemical - large, insoluble molecules are broken down into smaller, soluble molecules by enzymes through hydrolysis reactions
What is the substrate of amylase?
starch
What is the substrate of maltase?
maltose
What is the substrate of lactase?
lactose
What is the substrate of lipase?
triglycerides
What is the substrate of sucrase?
sucrose
What is the substrate of exopeptidase?
polypeptides and dipeptides
What is the substrate of endopeptidase?
polypeptides
What is the product of starch?
maltose