Download Enzyme Notes - Ms. Fox's Science Spot

Enzymes
Unit 2
What is an enzyme?
• An enzyme is a special protein
+
What are they made of?
• Enzymes are made of amino acids (just
like proteins!!!)
The lock and key model
What do they do?
• Enzymes start or speed up the rate of a
chemical reaction.
How do they do that?
• Enzymes lower the activation energy
– They make it easier for the reaction to start
like lowering a hurdle
energy (kJ)
Ea without enzyme
Ea with enzyme
reaction (time)
What is a chemical reaction?
• A chemical reaction is where atoms are
rearranged into a different order
Reactant 1 + Reactant 2
Product
– Reactants go into the reaction (left)
– Products come out of the reaction (right)
How do they help with a chemical
reaction?
• Enzymes match up to a single partner like
a lock and a key
– We say they are specific
↔
+
enzyme
+
reactant
↔
↔
enzyme-reactant
complex
+
↔
enzyme
+
products
What happens when they are done
helping with the reaction?
• After enzymes help start or speed up the
chemical reaction they wait around to help
with another reaction
– We say they are reusable
What hurts enzymes?
• Enzymes do not like changes in
temperature.
What hurts enzymes?
• Enzymes do not like changes in pH.
What happens to an enzyme when
temperature or pH changes?
• Enzymes denature (lose their shape, die)
in extreme temperatures or pH.
heat
pH
normal
denatured