enzymes and digestion

enzymes

proteins

biological catalysts that speed up the rate of a reaction without being used up itself

active site

allows substrate to fit into it

as each enzyme has a specific shape -----each enzyme can only catalyse a specific reaction

lock and key model

small make large

large break into small





substrate molecules fit into the active site


an enzyme-substrate complex is formed which allows bonds to be formed between the molecules


makes bigger molecule

large substrate molecule fits into the active site


enzyme-substrate complex is formed - allows bonds to break


2 smaller product molecules made

best

temperature

pH

concentration of enzyme

for many enzymes it'll be around 37*C (body temperature)

own optimum pH

kinetic energy

collisions

rate of reaction

^^ active site= irreversibly destroyed -- enzyme = denatured

lipase = 8


protease = 2

above or below optimum pH = denatured

start

end

increasing the enzyme concentration has no effect on the rate of reaction. substrate = LF

the more enzyme there are the faster the rate of the reaction. cuz there are more active sites for the substrate to fit into

enzyme inhibitors

similar shape to substrate

fits partially into the active site X the substrate

reduce or slow down the rate of reaction

digestion

is the breaking down large complex insoluble molecules into small soluble molecules

digestive enzymes

made in glands and lining of the gut

carbohydrase

amylase

protease

lipase

carbohydrate

simple sugar-glucose

starch

simple sugar-glucose

protein

amino acids

fats/lipids

glycerol & 3 fatty acids

pH

alkaline

acidic

stomach

kills bacteria in food

provides a low pH for enzymes to work

small intestine

bile

bile is produced by liver stored in gall bladder >> small intestine

emulsifies fats- larger surface area for lipase to work

neutralises the acid that was added to the food in stomach

provides alkaline conditions for enzymes