Enzymes
A quick guide
Enzymes
• Enzymes make the chemical reactions in
our body happen at a faster rate
• A chemical that speeds up a reaction is
called a catalyst.
• Enzymes are often called biological
catalysts.
• http://www.lpscience.fatcow.com/jwanama
ker/animations/Enzyme%20activity.html
Breakers and Builders
• Enzymes come in two main types:
1. Breakers- these break down large
molecules into smaller ones. This is
important in digestion
2. Builders- these join small molecules
together to make large ones. These build
important molecules inside our cells
How an enzyme works
• Enzymes work on
substances called
substrates.
An enzyme in action
An enzyme in action
• The substrate fits into the active site of the
enzyme.
• The enzyme breaks the substrate down
into smaller molecules called products.
http://www.lpscience.fatcow.com/jwanamake
r/animations/Enzyme%20activity.html
Common Enzymes
Enzyme: Amylase
Substrate: Starch
Product: Glucose
Enzyme: Catalase
Substrate: Hydrogen peroxide
Products: Water & Oxygen
Important Properties
1. They are all proteins
2. Each enzyme controls one particular
reaction.
3. They can be used again and again.
http://www.lewport.wnyric.org/jwanamaker/a
nimations/Enzyme%20activity.html
4. They are affected by temperature.
5. They are affected by pH.
Enzymes are specific
• This means that they only work with one
particular substrate.
• No other substrate can fit into the active
site of the enzyme.
http://www.lpscience.fatcow.com/jwanamake
r/animations/Enzyme%20activity.html
Enzymes are affected by
temperature
• Warm an enzyme and they work faster.
• But if they get too hot they stop working.
• There is an optimum temperature where
they work best.
Enzymes are affected by
temperature
• Enzymes are made of proteins. At high
temperatures, the proteins break down.
• The shape of the active site changes, so
the substrate can no longer fit.
• We say that the enzyme has been
denatured. It no longer works.
http://www.lpscience.fatcow.com/jwanamake
r/animations/Enzyme%20activity.html
Enzymes are affected by pH
• Change the pH and the shape of the
active site will change.
• Every enzyme has optimum pH at which it
works best.
Pineapple enzyme lab…
• LAB QUESTIONS:
• 1. Write a short summary paragraph in which you describe what you
have learned and/or what you can conclude about enzymes.
• 2. Create a visual image to represent the enzyme-catalyzed reaction
used in these labs. Label the substrate, active site, enzymesubstrate complex, and the products. Assume the products are 4
small chains of amino acids.