Enzymes (2.5) Flashcards
What type of proteins are enzymes? What are their functions?
Globular proteins. Catalyze biochemical reactions.
What is a catalyst?
Chemical agent that speeds up chemical reactions inside an organism without being consumed by the reaction.
What happens after an enzyme catalyzes a reaction
It’s used over and over again by a assuming its original shape after the reagent-product conversion.
What is the name given to the molecule that binds to the enzyme?
substrate.
What’s the relation between the substrate and enzyme?
The substrate perfectly fits in the active site of the enzyme
Enzyme + substrate: Product
(e.g. Maltase + Maltose = Glucose + Glucose
What is the name of the bond created by the enzyme and substrate?
enzyme-substrate bond.
Enzymes usually end with:
Sugars usually end with:
- ase
- ose
What is the induced fit?
It is the shape incorporated by the enzyme (there is a 3D alteration) after the bond of the substrate with the active site.
What happens during the induced fit?
The enzyme induces the weakening of the bonds within the substrate, lowering the activation energy needed for the reaction to take place.
What can affect an enzyme’s efficiency?
Temperature, pH, substrate concentration, and enzyme concentration.
How does temperature affect enzyme efficiency?
When temperature is low, molecules tend to move slowly. The chance of collision between substrate and enzyme molecules is also low. When temperature rises, molecules move more rapidly and it is more likely that they will collide with each other. At some point the enzyme will become denatured and lose its effectiveness.
How does pH affect enzyme activity?
Enzyme activity is at its maximum value at the optimum pH. As the pH value is increased above or decreased below the optimum pH the enzyme activity decreases.
Explanation
At very acidic and alkaline pH values the shape of the enzyme is altered so that it is no longer complementary to its specific substrate. This effect can be permanent and irreversible and is called denaturation.
The diagram below shows what happens to an enzyme when denaturation occurs.
A protein and a substrate are complementary shapes. The pH of the solution made very acidic or alkaline and they become non-complementary shapes.
Each enzyme has an optimum pH but it also has a working range of pH values at which it will still work well. This depends on the type of enzyme.
The enzyme pepsin breaks down proteins in the acidic conditions of the stomach. Pepsin has an optimum of pH 2.5 and a working range of between pH 1-4. Catalase has an optimum pH of 9 and a working range of between pH 7-11. Most other enzymes function within a working pH range of about pH 5-9 with neutral pH 7 being the optimum.
How does substrate concentration affect enzyme activity?
When the substrate concentration is low, there are more enzyme molecules available than the substrate. (the rate of a reaction is limited by the amounts of substrate present and available enzyme.)
When can denaturation be reversible?
Denaturation can be reversible when there is only a minor temperature increase or change in pH…..the protein can fold back to its original and functional conformation.
Describe how Enzymes can be used in the industrial environment.
https://docs.google.com/presentation/d/1cVjR4H43i0X1BKFpb1THmhZ-Clm1R1Eh1lo2aY9An_0/edit#slide=id.p
