Here's why:
* Enzymes: A huge number of proteins act as enzymes, which are biological catalysts that speed up chemical reactions essential for life.
* Structural Components: Proteins provide structure and support to cells, tissues, and organs. Examples include collagen, keratin, and actin.
* Transport: Proteins like hemoglobin carry oxygen in the blood, while others transport nutrients and waste products.
* Signaling: Proteins act as messengers, transmitting signals within and between cells.
* Defense: Antibodies are proteins that protect the body from disease.
While other molecules like carbohydrates, lipids, and nucleic acids play vital roles, proteins are the most versatile and are involved in the vast majority of cellular functions.
