enzymes Flashcards
what are enzymes
proteins which are biological catalysts (speed up chemical reactions)
they are specific and catalyse only one reaction
why can enzymes only catalyse one reaction
they have a specific shaped active site which only fits a specific substrate
what is the difference between -ase and -ose
-ase is enzymes
-ose is sugars
what enzyme breaks down proteins
protease
what enzyme breaks down carbohydrates
carbohydrase
what enzyme breaks down lipids
lipase
induced fit theory
The active site approximately fits the substrate and flexes slightly to fit the substrate after bonding
synthesis of substrates
two substrates join together in an enzyme substrate complex, forming a single product
digestion/breakdown of substrates
one substrate splits apart in an enzyme substrate complex, forming 2 products
why do some bacteria/fungi release enzymes into their surroundings
to digest large biological molecules which can diffuse across the cell surface membrane into the organism
what is a substrate
the molecule that is changed in a reaction
what is a denatured enzyme
an enzyme which has permanently changed shape due to high pH or temperature. the active site no longer fits the substrate
breakdown of hydrogen peroxide (H2O2) by catalase
-set up apparatus (flask connected to water cylinder via delivery tube submerged in water trough)
-add potato extract and hydrogen peroxide to flask
-every 30s, record volume of oxygen in measuring cylinder
(hydrogen peroxide is broken down by catalase into water and oxygen)
benedict’s test
REDUCING SUGARS
-Mix food substance with benedict’s solution and place in 75’C water
-Blue = no reducing sugar
Red = large amount of reducing sugar
Biuret’s test
PROTEINS
-Biuret solution is potassium hydroxide and copper sulphate
-Darker colour = more protein
