Why can different adult proteins be produced from calliphorin in a fly larva?

• A. Amino acids from calliphorin can be joined in different sequences
• B. Calliphorin acts as a catalyst for transcription
• C. Calliphorin cannot be used to make other proteins
• D. Calliphorin is a lipid used for energy

Answer: (A)

Proteins differ because the order of amino acids in a protein determines its shape and function. If you assemble the same pool of amino acids in different sequences, you get different polypeptides that fold into different proteins. So, from calliphorin in a fly larva, the amino acids can be joined in various orders to produce different adult proteins. The other statements don’t fit this idea: calliphorin isn’t known as a transcription catalyst, it’s not a lipid, and proteins aren’t inherently unable to contribute to the makeup of other proteins—amino acids from proteins can be reused to build new ones in general.