Questions: Protein synthesis is directed by a compound in the cell nucleus called ribonucleic acid (RNA) transfer RNA (tRNA) deoxyribonucleic acid (DNA) messenger RNA (mRNA)

The question seems to be about the role of different types of nucleic acids in protein synthesis. Let's address the relevant components:

Protein synthesis is a process that involves the creation of proteins based on the genetic instructions carried by nucleic acids. The main types of nucleic acids involved in this process are:

1. Deoxyribonucleic Acid (DNA): DNA contains the genetic blueprint for the synthesis of proteins. It resides in the cell nucleus and holds the instructions for making all the proteins in an organism.

2. Messenger RNA (mRNA): mRNA is synthesized from DNA during a process called transcription. It carries the genetic information from the DNA in the nucleus to the ribosomes in the cytoplasm, where protein synthesis occurs.

3. Transfer RNA (tRNA): tRNA is responsible for bringing the appropriate amino acids to the ribosome during protein synthesis. Each tRNA molecule has an anticodon that pairs with a corresponding codon on the mRNA strand, ensuring that the correct amino acid is added to the growing polypeptide chain.

4. Ribonucleic Acid (RNA): RNA is a broad category that includes mRNA, tRNA, and ribosomal RNA (rRNA). Each type of RNA plays a specific role in the process of translating genetic information into proteins.

In summary, protein synthesis is directed by DNA, which is transcribed into mRNA. The mRNA then guides the assembly of amino acids into proteins with the help of tRNA and rRNA.