What is the job of proteins in the human cell?

Proteins play vital roles in human cells, serving as the building blocks for cellular structure and function. They act as enzymes to catalyze biochemical reactions, facilitate communication between cells, and transport molecules across membranes. Additionally, proteins are involved in immune responses and the regulation of gene expression, making them essential for maintaining cellular health and homeostasis. Overall, proteins are crucial for virtually every biological process in the body.