📚 Topic Summary
Enzymes are biological catalysts that speed up chemical reactions in living organisms. They have a specific 3D structure that includes an active site where substrates bind. pH, a measure of acidity or alkalinity, profoundly impacts this structure and, consequently, the enzyme's activity. Each enzyme has an optimal pH at which it functions most efficiently. Deviations from this optimum can disrupt the enzyme's shape, altering the active site and reducing or even eliminating its catalytic ability. This disruption is often due to the protonation or deprotonation of amino acid residues critical for maintaining the enzyme's three-dimensional conformation.
The pH affects the charges on the amino acids in the enzyme. Changes in these charges can disrupt the ionic and hydrogen bonds that maintain the enzyme's shape. Extreme pH values can cause the enzyme to denature, which means the enzyme unfolds and loses its shape. Denaturation is often irreversible, rendering the enzyme inactive.
🧪 Part A: Vocabulary
Match the term to its correct definition:
| Term |
Definition |
| 1. Enzyme |
A. The unfolding of a protein, leading to loss of function. |
| 2. Active Site |
B. A substance that speeds up a chemical reaction without being consumed in the process. |
| 3. pH |
C. The location on an enzyme where the substrate binds and catalysis occurs. |
| 4. Denaturation |
D. The measure of the acidity or alkalinity of a solution. |
| 5. Optimal pH |
E. The pH at which an enzyme exhibits maximum activity. |
📝 Part B: Fill in the Blanks
Enzymes are biological ________ that speed up chemical reactions. Each enzyme functions best at its ________ pH. Extreme pH values can cause an enzyme to ________, leading to a loss of function. The pH affects the ________ on the amino acids in the enzyme. Changes in these charges can disrupt the ________ and hydrogen bonds that maintain the enzyme's shape.
🤔 Part C: Critical Thinking
Explain how altering the pH of a reaction environment can inhibit or enhance enzyme activity. Include specific examples of how changes in pH affect the enzyme's structure and active site.