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/jwanamaker/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.

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Common Enzymes

Enzyme: Amylase Substrate: StarchProduct: Glucose

Enzyme: CatalaseSubstrate: Hydrogen peroxideProducts: Water & Oxygen

Important Properties

1. They are all proteins2. Each enzyme controls one particular

reaction.3. They can be used again and again.http://www.lewport.wnyric.org/jwanamaker/animations/Enzyme%20activity.html4. 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.

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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.

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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, enzyme-substrate complex, and the products. Assume the products are 4 small chains of amino acids.