What is the substance that serves as the building block of proteins?

The substance that serves as the building block of proteins is amino acids. Proteins are composed of long chains of amino acids linked together by peptide bonds. There are 20 different amino acids that can be combined in various sequences to create a wide variety of proteins, each with unique functions in biological systems, including structural roles, enzyme activity, and the regulation of tissues and organs.

Amino acids contain both an amino group and a carboxyl group, and differ from one another by their side chains, which dictate the properties of the proteins they form. When proteins are synthesized in the ribosome, the sequence of amino acids is determined by the genetic code carried by messenger RNA, allowing for the precise construction of proteins essential for life.

In contrast, carbohydrates, nucleotides, and fatty acids serve different roles in biological processes. Carbohydrates primarily provide energy and structural components in cells. Nucleotides are the building blocks of nucleic acids like DNA and RNA, which are involved in genetic information storage and transfer. Fatty acids are involved in constructing lipids, which are essential for cell membranes and energy storage. Understanding the unique roles of these biomolecules is fundamental in biotechnology and molecular biology.