Which of the following molecules in eukaryotic cells play a direct role in regulating gene expression?

• A. DNA polymerase
• B. tRNA synthetases
• C. Transcription factors
• D. Ribosomal proteins

Answer: (C)

Verified step by step guidance

1. Understand the role of gene expression regulation: Gene expression involves the process by which information from a gene is used to synthesize functional products like proteins. Regulation of gene expression ensures that genes are expressed at the right time, location, and quantity.
2. Identify the function of transcription factors: Transcription factors are proteins that bind to specific DNA sequences near genes to either promote or inhibit the transcription process. They play a direct role in regulating gene expression by controlling the activity of RNA polymerase during transcription.
3. Clarify why DNA polymerase is not the correct answer: DNA polymerase is an enzyme responsible for DNA replication, not gene expression regulation. It does not directly influence the transcription or translation processes.
4. Explain why tRNA synthetases are not involved in gene expression regulation: tRNA synthetases are enzymes that attach amino acids to their corresponding tRNA molecules during translation. While they are essential for protein synthesis, they do not regulate gene expression.
5. Discuss why ribosomal proteins are not the correct answer: Ribosomal proteins are structural components of ribosomes, which facilitate translation. They are involved in protein synthesis but do not directly regulate the transcription of genes.