Enzymes
- Due Jan 25, 2023 at 11:59am
- Points 9
- Questions 9
- Available Jan 7, 2023 at 12am - Feb 1, 2023 at 11:59pm
- Time Limit None
- Allowed Attempts 3
Instructions
Instead of a textbook, I have written my own explanations and assembled some videos. You will need to read this and watch the videos and then take these quiz questions to make sure that you understand the material. You will have 3 attempts at the quiz and it is open notes.
Learning Objectives
After reading this material and watching these videos, you should be able to:
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Explain the structure and function of enzymes. Specifically understand
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What Are Enzymes and How do They Work?
All living organisms depend on enzymes to catalyze (speed up) chemical reactions. Without enzymes, reactions would not occur fast enough to support life. There are many types of enzymes, active in all types of cells. Each reaction uses a specific enzyme.
In enzyme driven chemical reactions, the reactant is called a substrate. The enzyme and substrate must first collide with each other due to the random molecular motion of the solution. Then amino acids lining the active site create attractions between the enzyme and its substrate. The enzyme then catalyzes the chemical reaction, produces the product. The enzyme is written above the arrow to indicate that it is unaltered by the reaction and can be used again (and again). Here is a specific example, and the one we will be using in lab. The enzyme is called catalase.
All enzymes are proteins. The amino acid sequence determines the three-dimensional shape of the enzyme. This shape is critical because it allows the enzyme to interact with its substrate molecule, the molecule that the enzyme works on. Enzyme action changes the substrate into a product(s). The enzyme itself remains unchanged in the reaction, it can be reused. Each enzyme works best at a specific temperature and pH. Most enzymes in the human body exhibit maximal activity at 37oC and a pH of around 7. Extremes in temperature and pH can change the shape of the enzyme rendering it inactive.
Watch these videos to help visualize the information from the paragraph above.
Ignore the material about induced fit vs. lock and key.
Ignore the material about calculating the rate of reaction
Do you understand? (Metacognition)
Test your understanding by answering these study guide questions and then to take a quiz on the topic.
Explain how the amino acid sequence of an enzyme determines the shape of the active site (structure). Why are enzymes so specific? Make sure to use the following vocabulary: amino acid side chain, amino acid interactions, protein folding, shape of active site and shape of substrate(s).
Why do all living organisms need enzymes to catalyze reactions? Make sure to use the following vocabulary: chemical reactions, rate of reactions.
What would happen to an enzyme reaction if there were low concentrations of the substrate? Make sure to use the following vocabulary: collision, active site, substrate, reaction rate.