Select all that apply. Proteins vary widely in structure, whereas nucleic acids have rather uniform structures. How do you account for this major difference? Nucleic acids have many uses. Nucleic acids play an essential role in protein synthesis. Compared to proteins, which are made of up to 20 different amino acids, the composition of nucleic acids is considerably simpler. Proteins play an essential role in nucleic acids synthesis. Proteins have many uses. A DNA or RNA molecule contains only four types of building blocks: purines, pyrimidines, furanose sugars, and phosphate groups. Proteins have very specific and limited functions. Compared to nucleic acids, which are made up of many building blocks, the composition of proteins is considerably simpler. Nucleic acids have simpler, uniform structures because they are primarily used for protein synthesis.