Biology and Chemistry, Together at Last

Science courses have traditionally been taught as discrete subjects, with life sciences, chemistry, physics and other core subjects existing as distinct topics. There are many reasons for this, including state and national standards that prioritize the mastery of subject-specific concepts. For example, although the Next Generation Science Standards (NGSS) highlights the importance of crosscutting concepts these only superficially include other scientific disciplines. However, as we all know, science does not exist in a vacuum and these subjects are inherently linked. Similar to the push to incorporate technology, engineering, art, and mathematics into a science curriculum (often referred to as STEAM), educators have recently moved to feature the interactions between life sciences and other science disciplines. Perhaps the most consistent overlap exists between biology and chemistry.

Photo by Polina Tankilevitch on Pexels.com

You Got Chemistry In My Biology

Fortunately, it’s easy to incorporate chemisity into your life science classroom. In fact, many common biology experiments feature a significant amount of chemistry. For example, many biological processes depend on enzymes to catalyze a chemical reaction – lowering the activation energy required for a the reaction to proceed. Enzymes, therefore, are often thought of as a molecular machine formed by the proper folding of amino acids. These amino acids contain a relatively simple chemical structure: an amine group (NH2), a carboxyl group (CO2H), and an R side chain. This side chain determines the polarity and pH of the amino acids, and in turn the order of amino acids in a protein will determine the way a protein bends and folds.

Even the most complex protein folding depends on simple interactions between amino acids.

Enzyme kinetics are also tightly controlled by the chemical makeup of the solution. Changes to the pH can have significant effects of the rate that a reaction takes place, and extreme pH changes can fully inhibit the reaction. In addition, the concentration of both the enzyme and substrate influences the rate of the reaction. Finally, many enzymes require chemical cofactors, non-protein chemical compounds that are required for the protein’s activity. For example, magnesium is an essential cofactor to over 300 enzymes in the human body, including DNA polymerase. Because of this, magnesium is a key component in every polymerase chain reaction (PCR)!

The Chemistry of Electrophoresis

Even common life science laboratory techniques depend on a significant amount of chemistry concepts. For example, DNA and protein electrophoresis is used daily in molecular biology laboratories worldwide to separate complex samples. Although electrophoresis experiments are primarily concerned with the biological materials being examined, the process depends on the chemical structure of the biomolecules and the pH, concentration, and composition of the electrophoresis buffer. Additionally, the stains used to identify the DNA or protein depend on the chemical structure and charge of the biological molecules. Visible dyes, like methylene blue, can bind to nucleic acids through electrostatic interactions – the cationic dyes will bind to the negatively charged regions of DNA and RNA. Fluorescent dyes often intercalate between base pairs or fit into the major or minor grooves in the nucleic acids. Importantly, the chemical structure of both the nucleic acid and dyes determines binding efficiency and specificity. 

Hoechst dye binding to the minor groove of a DNA strand

Finding Chemistry In Your Curriculum

It is evident that many life science experiments contain a significant number of basic chemistry concepts, but as we previously mentioned many existing graduation standards ignore this overlap between subjects. How then can you incorporate chemistry into your biology classroom? The easiest method is to ask students to think about the chemical implications of the experiments they are already performing. Why is the solution kept at a specific pH or concentration, why is a certain chemical added to the experiment, and how does the chemical structure of the components influence the outcome? This method can be used in almost every laboratory activity, from electrophoresis to bacterial transformation, enzymatic reactions, and antigen-antibody interactions.

It’s also possible to bring chemistry into your existing curriculum through targeted experiments that focus on real-world applications. Edvotek now offers a wide range of chemistry kits that cover important biological concepts, including food sciences, medical diagnostics, and forensics. Many of these experiments are already common in biology classrooms, but our new kits allow students to focus on the chemical or biochemical reactions at the foundation of these techniques. Check out all of our chemistry offerings here!

Students benefit from an integrated curriculum, including understanding of the interactions between the major scientific disciplines. We hope that we have given you some ideas on how to incorporate chemistry into your classroom!