Authors: GEORGIOS CHATZIGEORGIOU, biology teacher, 2nd General Lyceum of Oreokastro, Greece, ALEXANDROS TERZOPOULOS, Mentor
We would like to express our utmost gratitude to Ms Konstantina Sarantavga, Principal of the 2nd General Lyceum of Oraiokastro, for her continuous help and support in implementing the STEM activity in our school.
General overview of enzymes
Enzymes are proteins capable of catalysing biochemical reactions in living organisms. As biocatalysts, they accelerate such reactions by lowering the activation energy thereof. Enzymes possess a varying degree of specialisation with respect to the reactants (substrates) of the reactions they catalyse; for their action, the binding of the substrate to the region of the protein known as the active site is required (in a lock-and-key manner). The velocity of enzymatic reactions is affected by temperature, substrate and enzyme concentration, binding affinity, pH etc. The enzyme function may be halted or increased by the presence of various substances (e.g. inhibitors, activators, allosteric effectors). Inhibition may be reversible or non-reversible.
Relevance to school curriculum-Benefits of our approach
The subject and encompassed disciplines are part of the curriculum for the General Orientation Biology course mandatorily taught in the 2nd Class of the General Lyceum (5th year of secondary education) in Greece. Enzymes specifically are taught within the framework of Chapter 3 “Metabolism”, section “Enzyme-Biocatalysts”. The time allocated for this section is one class sessions for the theoretical part, and an additional 1-2 hours to complete the experimental section designed herein.
The teaching approach we followed replaces the typical “dry” theory-repetitive presentation of this subject in the class with inquiry-based learning, including a hands-on experience in the lab with a strong visual stimulus. In our first implementation, 15 students participated (most of them girls) who showed great interest in the way the STEM fields of Biology and Chemistry were explored with this activity.
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