Proteins that speed up chemical reactions are called

• A. Hormones
• B. Carbohydrates
• C. Enzymes
• D. Lipids

Answer: (C)

Enzymes are proteins that act as catalysts, speeding up chemical reactions by lowering the activation energy required for the reaction to proceed. They achieve this by providing an active site where the substrate binds, aligning molecules to react more readily, and then releasing the products after the reaction. Enzymes are highly specific for their substrates and are reused many times, functioning best under particular conditions of pH and temperature. Hormones are signaling molecules that regulate body processes, carbohydrates are sugars used for energy and structure, and lipids are fats and related molecules mainly involved in energy storage and membranes. Because a protein that speeds up reactions is an enzyme, enzymes are the correct choice.