Which type of organic compound includes enzymes that catalyze biochemical reactions?

The correct answer is proteins because they serve as biological catalysts known as enzymes, which play a crucial role in accelerating biochemical reactions within living organisms. Enzymes lower the activation energy required for reactions, enabling them to occur more rapidly and efficiently, which is vital for processes such as digestion, metabolism, and DNA replication.

Proteins are composed of long chains of amino acids that fold into specific three-dimensional structures, allowing them to interact with substrates and facilitate reactions. Each enzyme has a unique active site that binds to its specific substrate, promoting the conversion of reactants to products.

In contrast, carbohydrates primarily serve as energy sources and structural components in cells, while sugars refer specifically to simple carbohydrates. Nucleotides are the building blocks of nucleic acids like DNA and RNA, playing key roles in genetic information storage and transfer but do not function as catalysts for biochemical reactions. Thus, proteins are uniquely positioned to function as enzymes.