The monomers of protein molecules are calledMultiple choice question.amino acids.monosaccharides.monoproteins.nucleic acids.

To answer your multiple-choice question regarding the monomers of protein molecules, let’s analyze the options provided:

1. Amino Acids

   • Amino acids are indeed the building blocks of proteins. Each protein is made up of one or more chains of amino acids that are linked together by peptide bonds. There are 20 different amino acids that combine in various sequences to create a vast array of proteins, and they play critical roles in biological processes.

2. Monosaccharides

   • Monosaccharides are the simplest form of carbohydrates, like glucose and fructose. These are not involved in protein synthesis but are crucial for energy production and providing structural components in cells.

3. Monoproteins

   • The term "monoproteins" is not commonly used in biochemistry to refer to a specific class of molecules. Instead, proteins are typically classified based on their structure and function.

4. Nucleic Acids

   • Nucleic acids (such as DNA and RNA) are polymers made up of monomers called nucleotides. They serve as the information carriers in cells but are not related to the formation of proteins directly.

Conclusion

Given this analysis, the correct option that fits the description of the monomers of protein molecules is amino acids.

Final Answer: Amino acids