digestive enzymes Flashcards
what do enzymes catalyse?
chemical reactions
what is a catalyst
a substance that speeds up the rate of a chemical reaction yet remains unchanged
what are enzymes?
large protein molecules
what do enzymes have on their surface?
they have a groove on their surface called the active site
what is the active site
the active site is where the substrate attaches to
what is a substrate?
it’s the molecule that the enzyme breaks down
enzymes are specific, what does this mean for the substrate?
The substrate must fit perfect into the active site (the lock and key theory)
what is the lock and key theory?
the the substrate must fit onto the active site of an enzyme
what are the specific enzymes of the digestive system?
proteases- breaks down proteins
amylase-breaks down carbohydrates
lipase=digests lipid molecules
where are proteases found?
the stomach , the pancreatic fluid and the small intestine
what are amino acids?
the long chains of chemicals
what happens when we digest proteins?
the protease enzymes convert the protein back to the individual amino acids, which are then absorbed into the bloodstream.
where are amino acids absorbed?
in the bloodstream
what happens when amino acids are absorbed?
when they are absorbed by the body cells, they are joined together in a different order to make human proteins
what does starch consist of?
a chain of glucose molecules
what is produced when carbohydrates like starch is broken down?
simple sugars
where is amylase found?
in saliva and the pancreatic fluid
what does a lipid molecule consist of?
a molecule of glycerol attached to 3 molecules of fatty acids
what produces glycerol and fatty acids?
when lipid molecules are digested by the enzyme lipase
what does lipase produce?
glycerol and fatty acids
where can we find lipase?
pancreatic fluid and small intestine
where is bile made and stored?
made and released by the liver
stored in the gall bladder
what is the function of bile ?
speeds up the digestion of lipids
breaks down fats into fatty acids
when bile converts large lipid droplets to smaller droplets. what do scientists call this.
this is when bike emulsified the liquid
what does bile emulsifying a liquid lead to?
increases the surface area of the lipid droplets (because they are broken down) which increase the rate of lipid breakdown by lipase
how does bile neutralise the stomach acid?
bile is an alkaline, it creates alkaline conditions in the small intestine
this also increases the rate of lipid digestion by lipase
name ways in which can increase the rate of lipid digestion by lipase.
bile being an alkaline and neutralising the stomach acid
bile emulsifying a liquid
what does it mean for bile to emulsify a liquid?
it converts large lipid droplets into smaller droplets.
