📚 Topic Summary
Enzymes are biological catalysts that speed up chemical reactions in cells. The active site is the specific region of an enzyme where the substrate binds and the reaction occurs. Many enzymes require assistance to function properly. These helpers are called cofactors and coenzymes. Cofactors are inorganic ions (like $Mg^{2+}$ or $Fe^{2+}$), while coenzymes are organic molecules (often vitamins or derived from vitamins). Coenzymes bind to the enzyme and participate in the reaction, often carrying chemical groups from one reaction to another. Without the proper cofactor or coenzyme, an enzyme may not be able to catalyze its reaction effectively.
🧠 Part A: Vocabulary
Match each term with its correct definition.
| Term |
Definition |
| 1. Active Site |
A. An organic molecule, often derived from a vitamin, that assists an enzyme. |
| 2. Cofactor |
B. The location on an enzyme where the substrate binds. |
| 3. Coenzyme |
C. A protein that acts as a biological catalyst. |
| 4. Enzyme |
D. An inorganic ion that assists an enzyme. |
| 5. Substrate |
E. The molecule upon which an enzyme acts. |
🧪 Part B: Fill in the Blanks
Fill in the missing words in the paragraph below:
An enzyme's _______ is where the _______ binds. Some enzymes need help from _______, which can be inorganic ions, or _______, which are organic molecules. These helpers are essential for the enzyme to _______ correctly and perform its catalytic function.
💡 Part C: Critical Thinking
Explain, in your own words, why cofactors and coenzymes are important for enzyme function. Give a specific example of a coenzyme and its role in a biochemical pathway.
