the digestive system Flashcards
(29 cards)
what do teeth do?
teeth break down food mechanically
what enzyme does saliva contain?
amylase
what do the Peristalis muscles do?
move food down the oesophagus and through the rest of the system
what does the stomach do?
the stomach contains hydrochloric acid and enzymes that chemically digest food
what is absorbed in the large intestine?
water is absorbed into the bloodstream
what is absorbed in the small intestine?
nutrients like glucose are absorbed into the bloodstream by the villi in the small intestine (starch is too large)
what does the liver produce?
the liver produces bile that is stored in the gall bladder before going into the small intestine
what does bile do?
bile emulsifies lipids to form droplets, increasing their surface area
it also neutralises stomach acid
where is waste excreted?
through the anus
what are enzymes?
-enzymes are proteins which act as biological catalysts
-break down large insoluble molecules into smaller, soluble molecules that can be absorbed into the bloodstream
what are the three main types of digestive enzymes?
carbohydrases, proteases and lipases
what do carbohydrases do?
break down carbohydrates into simple sugars such as glucose
what is amylase?
- a carbohydrase which breaks down starch into maltose
where is amylase made?why?
-amylase is made in the salivary glands, the pancreas and the small intestine
-amylase from the salivary glands gets denatured by stomach acid and must be replaced by amylase from the pancreas and the small intestine
what is maltase and what does it do?
-maltase is a carbohydrase which breaks down maltose into glucose
what are proteases?
proteases are a group of enzymes which break down proteins into amino acids
where is pepsin made?
in the stomach
what does pepsin do?
pepsin is an enzyme which breaks down proteins into smaller polypeptide chains
where are protease enzymes made?
in the pancreas and small intestine
what do protease enzymes do?
protease enzymes break the polypeptide chains into amino acids
what are lipases?
lipases are enzymes that break down lipids (fats) to glycerol and fatty acids
where are lipase enzymes made?
they are produced in the pancreas and secreted into the small intestine
what are carbohydrates needed for and where are they sourced?
-they are needed for respiration to release energy
-they are sourced in bread, cereal, pasta and potatoes
what are fats&oils needed for and where are they sourced?
-store of energy
-butter, nuts
