enzymes DEFINITELY IN EXAM Flashcards
2 models of enzyme action
lock and key model
induced fit model
define lock and key model
substrate has to fit perfectly in the active site
define induced fit model
enzyme changes shape as it binds to the substrate
suggest 2 reasons why we can’t just make our cells ever warmer to increase rate of reactions
- heating our cells would require a lot of energy
- higher temperatures damage our cells
- higher temperature speed up non useful reactions
explain how increasing temperature causes an enzymes to denature
- high temperatures start to break the holding the enzymes together
- enzyme and it’s active site changes shape
- the enzymes active site will no longer be complementary to the substrate
factors that affect enzymes
- after 37 degrees Celsius most enzymes start to change (denature)
active site of enzymes changes too so the substrate doesn’t fit active site
optimum temperature= optimum rate of enzymes - pH
optimum pH depends on what part of the body the enzyme works in
most enzymes work best at pH of 7
in stomach the enzymes work best at a pH of 2
how do you figure out the rate of reaction
rate of reaction = how much a product or reactant changes by/ time it took change
- what enzyme is starch broken down by
- where is this enzyme found in the body
- what product is formed after starch is broken down
- amylase
- salivary glands, pancreas, small intestine
- simple sugars
maltose (into maltase into glucose)
- what enzyme are proteins broken down by
- where is this found enzyme in the body
- what product is formed after protein is broken down
- protease
- stomach, pancreas, small intestine
- amino acid
- what enzyme are lipids broken down by
- where is this enzyme found in the body
- what products are formed after protein is broken down
- lipase
- pancreas, small intestine
- glycerol and fatty acids
how does bile help with the digestion of lipids
- bile emulsifies the lipids
- which increases the surface area for lipase enzymes to break them down
what is the role of bile
bile is made in the liver and stored in the gall bladder
it is alkaline to neutralise the stomach acid
it emulsifies fat to form small droplets which increase the surface area.
the alkaline conditions and large surface area increase the rate of fat breakdown by lipase
helps to speed up the digestion of lipids (IS NOT AN ENZYME- bile emulsifies the lipids, increases the surface area of the lipid droplets and increases the rate of lipid breakdown by lipase)
what is an enzyme
a biological catalyst that speeds up reactions
what are proteins long chains of
proteins long chains of amino acids
describe a lipid molecule
lipid molecule consists of a molecule of glycerol attached to 3 molecules of fatty acids