Final answer:
Proteins are composed of amino acids and have a unique three-dimensional structure. The genetic information for proteins is stored in a cell's DNA and is transcribed into mRNA. This mRNA is then translated into a protein by ribosomes.
Step-by-step explanation:
Proteins are essential macromolecules that play a variety of roles in cells. They are composed of amino acids, which are linked together to form polypeptide chains. Each protein has its own unique amino acid composition and sequence, which determine its three-dimensional structure. Proteins can fold into a stable conformation, which is important for their function. The genetic information that encodes each protein is stored in a cell's DNA, which is found in the nucleus of eukaryotic cells. When a cell needs to make a specific protein, it undergoes a series of processes known as gene expression, which involves the synthesis of mRNA and the subsequent translation of mRNA into a protein by organelles called ribosomes.