Week 27 – Sugar, Bacteria, and Chemical Reactions

This week chemistry focused on carbohydrates and organic reactions, and it connected perfectly to something I’ve written about since the beginning of this journal: sugar and cavities.

Sugar Is Chemistry, Not Just Taste

In class, we learned that sugars are small carbohydrate molecules — like glucose, fructose, and sucrose. Starch is a larger carbohydrate made of many sugar units linked together. When bacteria in plaque encounter these molecules, they treat them as fuel.

The reaction that matters for teeth is fermentation. Oral bacteria break down sugars and release acids (especially lactic acid) as byproducts. That acid is what lowers mouth pH and starts demineralizing enamel.

Frequency Beats Quantity

One idea from both chemistry and dentistry clicked for me this week: reaction time matters. It’s not only how much sugar you eat — it’s how often you restart the acid-producing reaction.

Each sugary snack or sip can trigger another round of bacterial fermentation. If those reactions happen throughout the day, enamel spends more time below the critical pH. That’s why sipping soda for hours can be worse than drinking it with a meal.

Sticky Foods Keep the Reaction Going

Sticky carbs (like candy or crackers) cling to tooth surfaces longer. In chemistry terms, that means the reactants stay available to bacteria for a longer period, so acid production continues. Rinsing with water or chewing sugar-free gum helps clear leftovers and supports saliva’s buffering work.

Final Thoughts

Week 27 made sugar feel less like a vague “bad food” warning and more like a clear chemical process: carbohydrates → bacterial metabolism → acid → enamel damage. Once you see the reaction pathway, prevention makes more sense.

Brushing, flossing, and smarter snacking aren’t random rules. They’re ways of interrupting a chemical chain reaction before it reaches your teeth.