If an enzyme is placed in a lower than optimal pH, its loss of activity might be due to

denaturing of the peptide bonds

Explanation:

Enzymes are proteins that help speed up chemical reactions. However, they require specific temperatures and pH's to work optimally and produce the best outcome.

If an enzyme is placed in a lower than optimal pH, that means that there are more H+ ions, and the environment is more acidic. This influx of H+ ions can denature the peptide bonds within the enzyme, causing it to fold in a different way and be unable to carry out its normal duties. Hence, the activity of the enzyme will decrease significantly.

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