OCR General Certificate of Secondary Education (GCSE) Biology Practice Exam

What type of protein is collagen classified as?

1. Enzymatic protein

2. Transport protein

3. Structural protein

4. Contractile protein

The correct answer is: Structural protein

Collagen is classified as a structural protein because it plays a critical role in providing support and strength to various tissues in the body, such as skin, bones, tendons, and ligaments. It forms a fibrous network that helps maintain the integrity and elasticity of these structures, making it essential for overall tissue health and resilience. In contrast to other protein types: - Enzymatic proteins catalyze biochemical reactions and are crucial for metabolic processes but do not primarily provide structural support. - Transport proteins facilitate the movement of substances across cell membranes or within the bloodstream; they do not serve as structural components. - Contractile proteins are involved in muscle contraction and movement but are not designed for providing support to tissues like collagen. Thus, collagen's main function is as a building block in structural frameworks, solidifying its classification as a structural protein.