Enzymes ReadingA substance that helps a chemical reaction to occur is a catalyst, and the special molecules that catalyze biochemical reactions are called enzymes. Almost all enzymes are proteins, made up of chains of amino acids, and they perform the critical task of lowering the amount of energy needed for the chemical reaction to take place inside the cell. Enzymes do this by binding to the reactant molecules, and holding them in such a way as to make the chemical bond-breaking and bond-forming processes take place more readily.
The chemical reactants to which an enzyme binds are the enzyme’s substrates. There may be one or more substrates, depending on the particular chemical reaction. In some reactions, a single-reactant substrate is broken down into multiple products. In others, two substrates may come together to create one larger molecule. Two reactants might also enter a reaction, both become modified, and leave the reaction as two products. The location within the enzyme where the substrate binds is called the enzyme’s active site. The active site is where the “action” happens, so to speak. Since enzymes are proteins, there is a unique combination of amino acids in the enzyme's active site. The unique combination of amino acid, their positions, sequences, structures, and properties, creates a very specific chemical environment within the active site. This specific environment is suited to bind to a specific chemical substrate (or substrates). Due to this jigsaw puzzle-like match between an enzyme and its substrates, enzymes are known for their specificity. The “best fit” results from the shape and the attraction to the substrate of the amino acids in the active site . There is a specifically matched enzyme for each substrate and, thus, for each chemical reaction. Each enzyme will work with only one type of substrate. This is called the "lock and key" hypothesis. |
Watch this video as a whole class.
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Sign up for groups on canvas. See this link for how to join a group.
Also sign up on this google doc. Please note that there are different sheet for each class. |
See below "Designing your experiment: - things to consider. Make sure you answer these questions to yourself before class ends.
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See below "Sample procedure for the control experiment." Use this as a guide for what your procedure should look like. Then use the handout provided in order to write the answers for questions 1, 3, and 4. Answers to those questions are due at midnight tonight (Fri-2nd).
There is also a section below called "After writing your procedure make sure..." Read this over and make sure you have met the standard for this assignment. |
If it is easier for you to type into a goole doc that is already formatted for you then please make a copy of this one. Once you have your copy, you can share it with the other members of your group. You should complete questions 1, 3, and 4. I have put comments to the right on the google doc with the specific questions to answer and things you should make sure you have explained. At the end of the class, one person should submit your copy of this document to canvas. Technically you have until midnight so if you want to do some edits thats fine but make sure you know who is responsible for turning in the assignment and when they will have it turned in by so you can check and make sure the work it turned in on time.
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Sample procedure for the control experiment:
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Preparing the gelatin:
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