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How do proteins help cells carry out chemical reactions?
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Biology
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Proteins help cells carry out chemical reactions primarily by acting as enzymes, which function as biological catalysts. These proteins regulate the rate of biochemical processes, allowing reactions to occur at speeds necessary for life that would otherwise be too slow to sustain a cell.12
How Enzymes Work
Enzymes facilitate reactions by lowering the activation energy required for a chemical change to take place. The process generally follows these steps:2
- Binding: A specific region of the protein, known as the active site, binds to a specific substrate. This site is a unique groove or pocket formed by the protein's specific three-dimensional folding pattern.32
- Complex Formation: The enzyme and substrate form an enzyme–substrate complex. The protein may undergo a change in shape to bring reactive groups together, facilitating the transformation.324
- Catalysis: The enzyme catalyzes the reaction, sometimes forming a temporary covalent intermediate with the substrate, to form the final products.3
- Release: The products dissociate from the enzyme, leaving the protein unchanged and ready to catalyze another reaction.32
Because enzymes are not consumed in the process, they can be used repeatedly, allowing a small quantity of protein to catalyze thousands of reactions per minute.2