Topic 4.2: Protein Synthesis Questions

State the name of the enzyme that carries out transcription.

State the name of the structure that reads the mRNA codons and joins the amino acids together during translation.

Which type of bond joins neighbouring amino acids together in a polypeptide?

What is the role of a tRNA molecule in translation?

State what is meant by a codon.

Which event takes place during translation?

Calculate the number of amino acids in the polypeptide it encodes.

Which enzyme carries out transcription, and what does it produce?

How many bases of an mRNA molecule are read together as a single codon?

What does it mean to say that the genetic code is universal?

During transcription, which base is added to the mRNA opposite an adenine (A) on the DNA template strand?

Where in the cell does translation take place?

In which part of a eukaryotic cell does transcription take place?

A single base in an mRNA codon changes so that UUU becomes UUC. Both UUU and UUC code for phenylalanine. Explain, using the idea of degeneracy, why this change has no effect on the protein produced.

RNA polymerase and DNA polymerase are two enzymes that act on nucleic acids. Distinguish between the roles of RNA polymerase and DNA polymerase, and explain why mRNA is important for making a protein.

A section of mRNA has the base sequence AUG–UUU–UCU–UAU. A codon table shows: AUG = methionine (start), UUU = phenylalanine, UCU = serine, UAU = tyrosine. Deduce the order of amino acids in the polypeptide coded by this mRNA, and outline how you used the genetic code to work it out.

A drug (rifampicin) inhibits transcription by blocking RNA polymerase. What is the immediate effect on the cell?

Which statement correctly describes the role of mRNA in protein synthesis?

A codon table shows UCU = serine, UAU = tyrosine and CAU = histidine. Which order of amino acids does the mRNA sequence UCU–UAU–CAU code for?

Which statement correctly describes what it means for the genetic code to be degenerate (redundant)?