enzymes
DESCRIPTION
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. E a without enzyme. - PowerPoint PPT PresentationTRANSCRIPT
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
reaction (time)
ener
gy
(kJ)
Ea with enzyme
Ea without enzyme
What is a chemical reaction?
• A chemical reaction is where atoms are rearranged into a different order
– Reactants go into the reaction (left)– Products come out of the reaction (right)
Reactant 1 + Reactant 2 Product
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↔products
enzyme
+↔
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.
• Enzymes do not like changes in pH.
What hurts enzymes?
What happens to an enzyme when temperature or pH changes?
• Enzymes denature (lose their shape, die) in extreme temperatures or pH.
normal denatured
heat
pH