This common misconceptions covers Common Misconceptions within Enzymes in Digestion for GCSE Biology. Enzyme structure and function, digestive enzymes, factors affecting enzyme activity, lock and key model, and practical investigations It is section 15 of 19 in this topic. Use this common misconceptions to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 15 of 19
Practice
20 questions
Recall
25 flashcards
Common Misconceptions
Misconception: "Enzymes are killed by high temperatures."
Reality: Enzymes are not alive, so they cannot be killed. The correct term is denatured. High temperatures break the bonds holding the enzyme's three-dimensional shape, permanently altering the active site. The protein still exists but can no longer function.
Misconception: "Enzymes are used up during reactions — you need more enzyme to keep the reaction going."
Reality: Enzymes are catalysts and are released unchanged after each reaction. The same enzyme molecule can catalyse thousands of reactions. Adding more enzyme speeds up the rate (more active sites available), but enzymes are not consumed.
Misconception: "All digestive enzymes work best at body temperature (37°C) and neutral pH."
Reality: While 37°C is typical for human enzymes, the optimal pH varies enormously. Pepsin in the stomach works best at pH 1.5 (strongly acidic), while trypsin in the small intestine works best at pH 8.5 (alkaline). Each enzyme is adapted to its specific location.