`alpha`-helix : secondary structure : : enzymes : ……………

Explanation

To solve the analogy presented in the question, we need to identify the relationship between the terms given. The analogy is structured as follows:

**Alpha-helix : Secondary structure : : Enzymes : ?**

### Step-by-Step Solution:

1. **Understanding the First Pair (Alpha-helix and Secondary Structure)**:
- An alpha-helix is a specific type of secondary structure found in proteins. Secondary structures are formed by the folding of the polypeptide chain into structures like alpha-helices and beta-sheets due to hydrogen bonding.
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