What term is used for the total molecular mass of a protein?

The correct term for the total molecular mass of a protein is "Daltons." This unit is specifically used to express the mass of biomolecules, including proteins, nucleic acids, and other macromolecules in biochemistry. One Dalton is defined as one twelfth the mass of a carbon-12 atom, making it a convenient scale for measuring the mass of very small particles like proteins, which can range from a few thousand to several hundred thousand Daltons based on their size and complexity.

Understanding that proteins are composed of amino acids and have a specific molecular weight determined by their sequence and structure helps clarify why Daltons are the appropriate measurement. Other measurements like atomic mass are used for individual elements or isotopes, gram weight generally refers to a mass measurement in grams, and calories are units of energy, not mass. Thus, the use of Daltons distinctly aligns with the molecular context of proteins.