A Level Biology Practice Exam 2025 – All-in-One Study Guide to Excel in Your A Levels!

Protein denaturation refers to the structural alteration of proteins due to factors such as changes in temperature, pH, or the presence of certain chemicals. This process disrupts the weak bonds and interactions that maintain the protein's specific three-dimensional shape. As a result, the protein loses its normal conformation, which is crucial for its function.

The loss of normal function is significant because proteins, including enzymes, rely on their specific shapes to bind substrates and catalyze reactions efficiently. When denatured, a protein can no longer perform its biological role, leading to decreased or completely lost activity. For example, enzymes that have undergone denaturation cannot catalyze reactions effectively because their active sites, which are essential for substrate binding, may no longer be configured correctly.

In contrast, denaturation does not lead to increased enzyme activity, normal protein folding, or improved structural integrity, as the protein's function is inherently connected to its structure. Thus, the correct outcome of protein denaturation is a loss of normal function.