What is the term for a complex protein that is a catalyst for chemical processes in the body?

What is the term for a complex protein that is a catalyst for chemical processes in the body?

• A. Hemoglobin
• B. Hormone
• C. Amino acids
• D. Enzyme

Answer: (D)

Enzymes are biological catalysts: complex proteins that speed up chemical reactions inside the body by lowering the activation energy needed for the reaction to proceed. They have specific shapes with an active site that binds substrates, often requiring cofactors or coenzymes to work, and their activity depends on conditions like temperature and pH. They show substrate specificity, so each enzyme acts on particular molecules. By contrast, hemoglobin transports oxygen, hormones are signaling molecules, and amino acids are the building blocks of proteins. So the term that fits is enzyme.

Enzymes are biological catalysts: complex proteins that speed up chemical reactions inside the body by lowering the activation energy needed for the reaction to proceed. They have specific shapes with an active site that binds substrates, often requiring cofactors or coenzymes to work, and their activity depends on conditions like temperature and pH. They show substrate specificity, so each enzyme acts on particular molecules. By contrast, hemoglobin transports oxygen, hormones are signaling molecules, and amino acids are the building blocks of proteins. So the term that fits is enzyme.