Enzyme Activity Assay
Enzyme Activity Assay - Related Videos
04:35
Enzyme Activity - Concepts
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2019
Biological Catalysts All living organisms continuously perform numerous biochemical reactions to sustain their presence. Most of these reactions require an input of energy to start, which is called the activation energy. Catalysts are chemicals that lower the activation energy. Even though catalysts facilitate a chemical reaction, they are not consumed by it. This means a catalyst can facilitate a specific chemical reaction over and over in succession, increasing the rate of that reaction.
09:05
Enzyme Activity - Student Protocol
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2019
Baseline Peroxidase Enzyme Experiment ExpandTo begin, the baseline for the peroxidase enzyme reaction must be determined. Make the substrate by adding 7 mL of distilled water to a clean test tube and then add 0.2 mL of guaiacol. Note: Guaiacol is a color-changing indicator that becomes more yellow-orange as the enzyme reaction progresses. Next, add 0.3 mL of 0.1% H2O2. Using a marker, label the test tube substrate and then cover the tube with a piece of sealing film. Holding the cover in place,...
02:20
Enzyme Activity - Instructor Prep
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2019
Investigating the Effect of pH and Temperature on Peroxidase Activity ExpandTo make the extraction buffer for the peroxidase enzyme, mix equal volumes of 0.1 M sodium phosphate monobasic and 0.1 molar sodium phosphate dibasic solutions to achieve a final volume of 500 mL. Test the resulting solution using a pH meter. The mixture should be between a pH of 6.8 and 7.2. To extract the turnip peroxidase, use a knife to remove the outer layer of a turnip and then cut the turnip into approximately...
08:07
Enzyme Assays and Kinetics
0 Views •
2023
Enzyme kinetics describes the catalytic effects of enzymes, which are biomolecules that facilitate chemical reactions necessary for living organisms. Enzymes act on molecules, referred to as substrates, to form products. Enzyme kinetic parameters are determined via assays that directly or indirectly measure changes in substrate or product concentration over time. This video will cover the basic principles of enzyme kinetics (including rate equations) and kinetic models. The concepts governing...
03:27
Insoluble Chromogenic Biomass-Based Enzyme Screening: An Assay to Evaluate the Degradation Activity of Plant Biomass-Degrading Enzymes
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2025
This video demonstrates an assay to screen enzymes effective in degrading complex polysaccharides in plant biomass using insoluble chromogenic biomass or ICB. The enzymes hydrolyze ICB to release soluble dye-linked oligosaccharides, and the enzyme activity is assessed by colorimetric analysis of the reaction product.
FAQs
The measured reaction rate reflects the combined effects of enzyme and substrate concentrations and the defined conditions used during the experiment. Keeping these factors controlled allows researchers to attribute differences in rate to the variable under investigation rather than to inconsistent assay setup. This control is essential when comparing samples, disease-associated changes, or treatment effects.
Enzyme abundance indicates how much of an enzyme is present, whereas activity reveals whether that enzyme is functioning catalytically. A sample can therefore show altered performance without a corresponding change in measured amount. In medicine, this functional distinction helps identify abnormal enzyme behavior and provides information about disease-related changes that concentration measurements alone may miss.
Reaction rates can be calculated by monitoring either the increase in product or the decrease in substrate over time. The assay converts one of these chemical changes into a measurable signal, such as absorbance or fluorescence, and uses the signal change to quantify catalytic performance. Choosing either measurement route can provide a functional readout of the same reaction.
An inhibitor response shows how strongly a candidate compound changes the enzyme's catalytic performance under the assay conditions. Comparing reaction rates with and without the compound enables a quantitative assessment of treatment effect. This approach helps characterize drug candidates by linking exposure to a measurable change in enzyme function rather than merely documenting compound presence.
A basic workflow combines controlled amounts of enzyme and substrate under defined assay conditions, then tracks product formation or substrate loss using an appropriate measurable signal. The resulting measurements are used to calculate reaction rate. Consistent setup and signal collection make it possible to compare enzyme activity across samples, experimental conditions, or candidate treatments.
Medical researchers and laboratories use these assays when functional enzyme information is needed. Diagnostic applications can reveal abnormal enzyme activity, while research applications can clarify disease pathways and evaluate candidate drugs. Because the result is quantitative, investigators can compare activity among samples or determine how strongly a treatment changes catalytic performance.
Measured enzyme activity can indicate how a disease-associated process changes catalytic function and can help characterize the pathway involved. The same assay framework allows researchers to test inhibitors or other candidate drugs by comparing reaction rates. These comparisons provide quantitative evidence of treatment effects and support decisions about which compounds merit further study.