Which is a key building block of proteins?

Amino acids are indeed the key building blocks of proteins. Proteins are large, complex molecules that play critical roles in the body, and they are made up of long chains of amino acids linked together by peptide bonds. There are 20 different amino acids that combine in various sequences to form proteins, each sequence determining the unique structure and function of the protein.

When proteins are synthesized in the body, specific sequences of amino acids fold and twist into unique three-dimensional shapes, allowing them to perform their biological functions, such as catalyzing biochemical reactions, providing structural support, and facilitating communication between cells. The unique properties of different amino acids, such as their size, charge, and hydrophobic or hydrophilic nature, influence the overall function and behavior of the resulting proteins.

The other choices represent different types of biological molecules or compounds. Fatty acids are key components of lipids, ammonia is a nitrogenous waste product, and simple sugars are carbohydrates that serve as energy sources. Although these molecules are vital for various biological processes, they do not serve as the building blocks of proteins.