b3 organisational and the digestive system Flashcards
what is the digestive system
mouth
salivary glands
aesophagus
stomach
liver
gall bladder
small intestine
large intestine
rectum
anus
what are enzymes
large proteins that catalyse reactions enzymes are not changed in the reactions they catalyse
what is the lock and key theory
1) the enzymes active site is a specific shape
2)the enzyme (lock)will only catalyse a specific reaction because the substrate(key)fits into its active site
3)at the active site enzymes can break molecules down into smaller ones or bind small molecules together to form larger ones
4)when the products have been released the enzymes active site can accept anotjer substrate molecule
how does ph affect enzymes
enzymes have optimum PH values for example part of the digestive system differ in ph
what are the digestive enzymes
amylase:produced in slaivary glands pancreas and small intestine breaks down starch into glucose
protease:produced in stomach pancreas small intestine breaks down proteins to amino acids
lipases:produced in pancreas and small intestine breaks down lipids to fatty acids and glycerol
what are digestive enzymes
they convert food into small soluble molecules that can be absorbed into the bloodstream
what is denaturation
at extremes of ph or at very high temperatures the shape of the enzymes active site can change. the substrate can no longer bind to the active site so the enzyme cannot catalyse the reaction
how do u test for proteins lipids starch and sugars
for proteins add biuret solution will turn mauve or purple if proteins present
for lipids add ethanol solution will turn cloudy is lipids present
for starch add iodine will turn blue black is starch is present
for sugar add benedicts solution will turn green yellow or red if sugar present
what does the mouth do
mouth:where food is chewed
what are salivary glands
salivary glands:make saliva containing the enzyme amylase
what is the aesophagus
aesophagus:carries food to stomach
what is the stomach
stomach:churns food releases protease releases hydrochloric acid
what is the liver
liver:makes bile
what is the gall bladder
gall bladder:stores bile bile is a alkaline to neutralise hydrochloric acid from the stomach emulsifies fat to form small droplets with a large surface area
what is the small intestine
small intestine:digested food is absorbed into the blood
