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Enzymes. Shapes. Entrepreneurship.  And why enzymes are like lovers, locks, and keys.

enzymes lock and key induced fit lovers holding hands

1-Minute NomNom

Enzymes are everywhere! According to Scientific American, there are 4000 reactions that are “known to involve enzymes”. These enzymes speed up chemical reactions, including many in food and cooking, making it possible for us to cook and digest all sorts of delicious foods. bread and enzymes - Bakery. Delicious bread on white backgroundThese include the enzymes that age beef (see the 1-Minute NomNom “Oh say can jui-cy, how much I’ve aged for you?“); those in yeast that break down the sugars found in starch when we bake breads and doughnuts (see “You’re pretty, but can you be fluffy? Yeast we can!“); and proteases, which are enzymes that digest collagen, such as the bromelain found in pineapples (see “Love meat tender, love meat sweet“).enzymes lock and key active site substrate Depositphotos_73310243_original (1)The way enzymes work is an instructive illustration of how shape plays an important role in science.  Enzymes work when they bind to other molecules (known as substrates).

“The basic mechanism by which enzymes catalyze [i.e. speed up] chemical reactions begins with the binding of the substrate (or substrates) to the active site on the enzyme. The active site is the specific region of the enzyme which combines with the substrate… The active site has a unique geometric shape that is complementary to the geometric shape of a substrate molecule, similar to the fit of puzzle pieces.” (Source: Elmhurst College)

. enzymes and lock and key model - Locks and Keys on Isolated White BackgroundThere are two ways this fit can take place. The first is the lock and key model. This is where the enzyme active site and the substrate molecule shape fit exactly inside each other, very much like how specific keys fit into specific locks (and hence the name of the model), thus “unlocking” and speeding up the reaction.

enzymes - induced fit model like boy and girl holding handsThe second model is the induced fit model. This is where the enzyme does not fit the substrate exactly, at least when they first meet. But the enzyme recognises the substrate and thus adjusts or modifies its shape to fit the substrate molecule’s shape.

Very much like two lovers holding hands, and their fingers and hands curl and interlock with each other (which we all know how that always gets a reaction!)

Research and entepreneurship in beer brewing led to the lock and key model of how enzymes work - Freehand drawing of the brewery scheme on the old paper. Card for brewery with tanks for storage of beer, bags of malt, hops, water, yeast, mug and barrels.Interestingly, the lock and key model was first conceptualised because of beer and entrepreneurship. The scientist who first thought of it was Emil Fischer. He developed this theory in the 1890s as he was deeply involved in researching the science of yeasts and fermentation of beer. Why? His father wanted to

“instill in his son a thorough understanding of fermenation… to capitalize on his involvement in the newly founded, and highly profitable, beer industry in Dortmund (Germany).” (Source: Molecules That Changed the World).

And that’s how our understanding of enzymes all began. Amazing what beer can do!


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photos: in order – depositphotos/kpatyhkayekophotostudiosciencepicsnewlightGekaSkrXarlyxa


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