Digestive system Flashcards
test for starch
iodine solution
if there is starch in food what colour will it change to
blue-black
test for simple sugars
Benedict’s solution
if there are simple sugars in food what colour will it change to
brick-red colour
test for protein
Biuret solution
if there is protein in food what colour will it change to
purple
test for lipids
ethanol
if there are lipids in food what colour will it change to
cloudy, white
where does digestion start
in the mouth by the teeth and salivary glands
how does saliva make it easier to swallow food?
acts as a lubricant
what is the function of the oesophagus?
to move food quickly and easily to the stomach
which organ produces bile?
liver
what is the function of bile?
breaks down lipids
where is bile stored?
gall bladder
what is the main function of the small intestine
absorbs products of digestion into blood
what are villi
microscopic, finger-like projections
what is the adaptations of villi that aid digestion
- many villi and micro villi: provides large surface area
- good blood supply: maintains diffusion gradient
- surface is one cell thick: short diffusion distance
- many mitochondria: provides energy for active transport
the main function of the large intestine
absorbs water and salts from remaining digestives food
what are the food groups
Carbohydrates, protein, fats, fibre, vitamins, water
digestion
the breaking down of food into smaller soluble molecules
active site
part of and enzyme molecule which has a special shape which lets them “lock” onto other substances
the function of an enzyme
to break down food into smaller, soluble molecules so it can be absorbed quicker
amylase
a carbohydrase - an enzyme that breaks down carbohydrates. made in salivary glands, pancreas and small intestine. starch ➡️ simple sugars
protease
made in stomach, pancreas and small intestine. protein ➡️ amino acids
lipase
made in pancreas and small intestine. lipids ➡️ fatty acids
what changes whether enzymes work best
temperature and pH conditions
optimum temperature
the best temperature for an enzyme to work in
can enzymes be in too hot conditions?
yes. it damages the enzymes which is denaturing
enzyme
biological catalysts which speed up the reaction of digestion
