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Biomedical Basics

Enzyme structure and function

  • Created by Henry Stewart Talks
Published on October 30, 2025   6 min

A selection of talks on Biochemistry

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This talk introduces enzyme structure and function, using it as a basis for further exploration of how enzyme architecture drives catalytic activity, specificity, and their essential roles in diverse biological processes. An enzyme’s activity depends on its three-dimensional structure. Enzymes are amino acid chains folded into specific shapes, starting with the primary sequence forming secondary structures like alpha helices and beta sheets, then folding into the functional tertiary form. Non-covalent interactions such as hydrogen bonds, hydrophobic interactions, van der Waals forces, and ionic bonds stabilize folding. Some enzymes are single polypeptide chains, while others assemble into a quaternary structure. These arrangements determine enzyme stability and define the properties of the active site, where catalysis occurs. The active site is a pocket on the enzyme where substrates bind and catalysis occurs. Though only a small part of the enzyme, its precise arrangement of functional groups gives it specificity and reactivity. Within this microenvironment, side chains of specific amino acids—often forming a catalytic triad or dyad—drive the reaction. Many enzymes also need “helpers,” such as coenzymes (organic molecules from vitamins) and metal ion cofactors, to boost reactivity. The arrangement and flexibility of active site residues bring substrates together, orient bonds, and enable transfer of electrons or protons.

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