Unit 8- Enzymes

Unit 8- Enzymes

What are enzymes?

Multiple Choice

Enzymes are what macromolecule?

• Nucleic Acid

• Lipid

• Protein

• Carbohydrate

Multiple Choice

A is the

• substrate

• enzyme-substrate complex

• products

Multiple Choice

Enzymes

• speed up chemical reactions

• slow down chemical reactions

• do nothing to a chemical reaction

Multiple Choice

What 3 letters do enzymes typically end in?

• -ose
• -ase
• -ese
• -tic

Multiple Choice

Enzymes speed up reaction rates by changing...

• Activation Energy
• pH
• Hydrogen Bonds
• Kinetic Energy

Multiple Choice

Which enzyme below is involved in the following chemical digestion process?
FATS---->FATTY ACIDS/GLYCEROL

• Lipase
• Trypsin
• Amylase
• Pepsin

Multiple Choice

__________________ converts fats to emulsified fats

• Bile juice

• Pancreatic juice

• Gastric juice

• Orange juice

Multiple Choice

Question: According to the graph, what is the ideal pH for Trypsin (an intestinal enzyme) in the human body?

• 37 degrees
• 8
• 2
• between 40 - 90 degrees

Why is shape important?

• The shape of an enzyme is very important because it has a direct effect on how it catalyzes a reaction.

Open Ended

Why do enzymes have different shapes?

Why is shape important?

• An enzyme’s shape is determined by the sequence of amino acids in its structure, and the bonds which form between the atoms of those molecules.

• Different types of enzymes have different shapes and functions because the order and type of amino acids in their structure is different.

Why are enzymes so specific?

• Enzymes are very specific about which reactions they catalyze.

• Only molecules with exactly the right shape will bind to the enzyme and react. 

• These are the reactant, or substrate, molecules.

Multiple Choice

The region where the substrate binds into a specific enzyme is referred to as the active site.

• True
• False

Why are enzymes so specific?

• The part of the enzyme to which the reactant binds is called the active site.

• This is a very specific shape and the most important part of the enzyme.

Activation energy

Enzymes reduce the activation energy of a reaction.

Ie. they reduce the amount of energy required for a reaction to take place.

Normally by bending substrate molecules in a way that facilitates bond-breaking

Multiple Choice

Question: Which is the best description of activation energy?

• Energy barrier needed to be overcome to initiate a reaction.

• Energy released as the reaction proceeds

• Energy stored within the reactant molecules.

• Energy stored within the product molecules.

You have 5 minutes to complete this in your books

Open Ended

What is the induced fit hypothesis?

Induced fit hypothesis

• The shape of Active Sites are not exactly Complementary, but change shape in the presence of a specific substrate to become Complementary

Induced fit hypothesis

• When a substrate molecule collides with an enzyme, if its composition is specifically correct, the shape of the enzyme’s Active Site will change and an Enzyme-Substrate Complex can form.​ ​ 

•  The reaction is then catalysed and an Enzyme-Product Complex forms.

Multiple Choice

B is the

• substrate

• enzyme-substrate complex

• products

Multiple Choice

A is the

• substrate

• enzyme-substrate complex

• products

Multiple Choice

Reading Passage: Enzymes are biological catalysts, meaning that they are molecules capable of speeding up chemical reactions. They are large, protein-based compounds that bind to the reactants in a chemical reaction and, through one or more mechanisms, assist in the reaction without being changed at all themselves. Because chemical reactions are so diverse, the mechanisms by which enzymes speed up chemical reactions are also varied.  However, one thing that enzymes have in common is that they are Catalysts that lower the activation energy for reactions. The lower the activation energy for a reaction, the faster the rate. Thus enzymes speed up reactions by lowering activation energy. Question: How do enzymes speed up chemical reactions involved in the digestion of food?

• Enzymes increase the pH of the reactants involved in the reactions.
• Enzymes reduce the amount of energy the reactions must have in order to occur.
• Enzymes reduce the number of atoms needed in the products of the reactions.
• Enzymes provide heat energy that speeds up the molecules involved in the reactions.

Tasks:

1) Draw a diagrams to show the induced fit model of enzyme activity:​

2) Describe what is happening at each stage of the diagram​

​3) Research and compare the differences between the two models of enzyme activity​

​4) Explain the role of enzymes in the body. Make sure you use the words "activation energy" in your answer​