Introduction: Biuret's Test
The food we consume is a complex mixture of several macromolecules like simple sugars, carbohydrates, lipids, proteins, etc. All these macros provide a surplus source of nutrition and energy for running the body’s metabolism. The human body is designed so that it requires a proportionate diet where each of these macros is assigned a specific role. It holds for proteins as well.
Proteins are the most overhyped food macromolecules of the 21st century. The supplement market is overwhelmed with proteins from people taking protein powders, whey proteins, and specific amino acid supplements like BCAA, L-threonine, beta-alanine, etc. No doubt proteins are important building blocks of the body. Their prevalence in the commercial market has reached new heights in the past few years.
With everyone aware of proteins and amino acids in our food, the need for biochemical tests at industrial and research levels is necessitated. Such a test is the “Biuret's Test”. It tests for the presence of bonds peculiar to proteins i.e. peptide bonds.
Students introduced to this test often find it difficult to learn its details, underlying principle, and its real-world applications.
We, at Labster, understand the complexities of this biochemical test. This article can provide some help as it attempts to identify the major issues encountered by students whilst studying this topic. It also lists practical solutions that teachers and educators can incorporate in their next class. By the end, we’ll convince you why a virtual lab simulation will prove useful not only for your students but also for you as an educator to deliver concepts more efficiently.
Why can the Biuret's Test be tricky to teach or learn?
There are 3 reasons why students dread and get confused about the topic of the Biuret's Test. Acknowledging these blocks is the first step toward making the topic more approachable.
1. Not comprehending the test's underlying premise
This is one of the main reasons why most students don’t understand the working of the Biuret's test and other biochemical tests performed for food macromolecules. When the underlying principle is unclear, the test becomes less logical and more theoretical to students. The ‘why’ (reason for performing the test) and ‘how’ (the underlying principle of the test) of each test performed for different macromolecules must be thorough to young learners.
2. The core concepts about macromolecules structures are weak
Directly teaching about the Biuret's test in your next class might not work. Many students aren’t sure of what constitutes a peptide bond in proteins and how it is formed. Basic knowledge about proteins, their structure, bonds involved, etc. are prerequisites before one moves on to complex topics like biochemical testing, reagents used for tests, etc.
3. Unsure of its practical uses
Learning a technique seems not helpful to students when they don’t know how to use it in their future research or industry job or businesses. Biuret's tests are often taught to students without educating them about their practical utility. This makes the learning journey non-conducive.
5 ways to make Biuret's Test a more approachable topic to understand
To address the issues encountered while teaching this topic, educators can engage the under-listed solutions in their classes. These can decode many different aspects of the Biuret's Test. Not only can they make teaching easier for educators like you but they will also make lessons clearer and easier to assimilate for your students.
1. Strengthen the core concept of proteins and their structures
This is our foremost advice to all the educators dealing with Biuret's tests. Designing biochemical tests that exploit the basic biochemistry of proteins at the molecular level necessitates the need for strong core concepts. You can begin with the underlisted examples in your next class.
Different types of food macromolecules (You can use the Introduction to Food Macromolecules simulation from Labster)
Basis of differentiating different food macromolecules
Introduction of proteins
Protein structure and its types (primary, secondary, tertiary, and quaternary)
Atoms involved in peptide bond
Synthesis of polypeptides (in vivo)
Different types of amino acids and their side chains
Inter and intramolecular forces involved in protein formation
Catering to these topics before moving to the explanation of the Biuret's test can ease the work for you. Additionally, it will encourage students to raise questions in a more open-ended manner during classroom teaching sessions related to “basic science”.
Figure: A GIF from the Biuret's test simulation by Labster. It can be used to simplify the core concepts important for understanding the techniques and its principle. It is available for School and University/College classes.
2. Teach them how to scientifically approach a problem
The Biuret's test is one of the many biochemical tests used in both academic research and the R&Ds of industries. Teaching your students how to scientifically approach a problem can help them reason out where Biuret's test can be applied and where it shouldn't be. This will help them in recognizing the practical applicability of techniques. It will also boost their confidence to translate theory lessons into practical experiments.
Teaching them how to set the experiment, use controls (both positive and negative controls), the meaning and importance of these controls, and drawing out conclusions by comparing the sample with controls can advance their scientific aptitude. You can also use The Scientific Method simulation from Labster where similar concepts are explained in detail.
Figure: A snippet from the Biuret's test simulation by Labster. It can explain how the peptide bond is formed and how it’s exploited in the Biuret's test. It is available for School and University/College classes.
3. Demonstrate the technique
Students are more likely to remember teachings and their specifics when they get hands-on experience with lab procedures. We understand that it’s not always possible for educators to conduct individual practice sessions for all the experiments. In such cases, we recommend at least demonstrating the experiment. Since the Biuret's test is based on a chromogenic change (color change), students might find it quite interesting when they observe the color change in front of their eyes.
You can use different food items like egg whites, rice, cheese, salad, cottage cheese, tofu, etc which are rich in proteins to conduct a practical class testing protein’s presence in them. Watch out for your students as the color changes of the Biuret test engage them in the class!
Additionally, you can increase participation by asking your students to bring a variety of foods from home that they believe to be high in protein so that you can include them in the experiment.
Figure: A snippet from the Biuret test simulation by Labster showing the benchtop setup of the experiment for checking protein content in different food items. It is available for School and University/College classes.
4. Simplify, don’t complicate!
Educators must simplify the science behind technical experiments. It's crucial to explain why the color in this experiment changes. If you simplify that for your students, half of the job is done.
Explain why the Biuret solution is blue. The initial color of the solution is blue because it contains copper ions. The Biuret solution is composed of copper sulfate (CuSO4) and sodium hydroxide (NaOH).
Explain how the presence of peptide bonds is exploited in this test. Copper sulfate present in the Biuret solution actively binds with the peptide bonds present in all proteins. This leads to the formation of a structure that gives a ‘violet color’ in an alkaline environment.
Explain the role of sodium hydroxide. Since the “CuSO4-peptide bond complex” gives a violet color ONLY in an alkaline environment, NaOH provides that environment in the experiment.
Figure: Chromogenic reaction in Biuret test involves a blue to violet color change. To be 100% sure of our results, the inclusion of positive and negative controls is very important. Blue is the negative control (no protein added to Biuret solution) while violet is the positive control (known protein added to Biuret solution). Image Source
5. Use virtual lab simulations
The Biuret's test is a practical technique used for the detection of proteins in food-based research labs and industries. When teachers and educators aren’t able to demonstrate the experiment in their class, theory lessons can be quite taxing for students.
We, at Labster, understand the issues faced by both students and teachers. Therefore, we encourage modern-day educators to make the most of Biuret's test simulation. It takes your students into a virtual world where they can understand how peptide bonds are formed, how proteins are synthesized from DNA, RNA, amino acids (central dogma of life), how the different controls are used, etc. It also helps your students to actively engage in the experiment using different food items like rice, eggs, green veggies, etc.
With virtual laboratory simulations from Labster, teachers can make more insightful points as students are rendered with better visual options where they can follow the different concepts freely.
Your students no longer have to struggle as our interactive Biuret's test simulation and gamification elements will help. By using this way of active and immersive teaching, our virtual learning platform takes an advent in the field of Science to make the upcoming scientists thorough with the “basics of their respective subjects”.