digestion of carbohydrates Flashcards
(21 cards)
what enzyme is needed to break down starch?
- amylase
- maltase
what is starch first broken down into?
maltose
what does maltose break down into ?
glucose
why does starch digestion stop in the stomach?
amylase enzyme is denatured by the low ph in the stomach acid
what do salivary glands secrete?
saliva, containing the enzyme amylase
where is amylase secreted from?
- salivary glands
- pancreas
why are enzymes broken down?
they are large and insoluble so cant be absorbed easily into the blood stream
where is maltose found?
i the brush border of the small intestine
what enzymes are found in the brush border of the small intestine?
- maltase
- lactase
where in the brush border are enzymes found ?
in the microvilli of the intestinal epithelial cells
write a word equation to show the break down of sucrose?
sucrose + water = glucose + fructose
write a word equation to show the break down of lactose?
lactose + water = glucose +galactose
name the enzymes that digest proteins
peptidases or proteases
where does protein digestion begin ?
in the stomach and continues in the small intestine
why is it beneficial to digest polypeptides in the middle to produce smaller peptides ?
to increase the surface area and provide more ‘ends’ for exopeptides
where are proteases found?
in the brush border of the small intestine
pancreas
describe the function of endopeptides
catalyse the hydrolysis of peptide bonds between specific amino acids in the middle of the polypeptide chain
describe the function of exopeptides
catalyse the hydrolysis of peptide bonds between specific amino acids in the ends of the polypeptide chain
what do endopeptides release ?
- dipeptides
- single amino acids
what do exopeptides produce?
- dipeptides
- amino acids
where do lipids begin to digest?
in the duodenum and is completed in the ileum
