Exam 14: Gene Expression: From Gene to Protein

A eukaryotic transcription unit that is 8,000 nucleotides long may use 1,200 nucleotides to make a protein consisting of approximately 400 amino acids.Which of the following statements best explains this fact?

A mutation in a cell results in a structural change in the signal-recognition particle (SRP)so that it does not bind to the translocation complex in the ER correctly.Which of the following processes will occur because of this mutation?

There are 61 mRNA codons that specify an amino acid,but only 45 tRNAs.This is best explained by the fact that

-Given the locally unwound double strand of DNA in the figure above,in which direction and on what strand does the RNA polymerase move during transcription?

Garrod hypothesized that inherited diseases such as alkaptonuria,the inability to metabolize the chemical alkapton,occur because

What is the effect of a nucleotide-pair substitution that results in a nonsense mutation in a gene?

-The figure above represents a tRNA molecule that recognizes and binds a particular amino acid (in this instance,phenylalanine).Which codon on the mRNA strand codes for this amino acid?

The anticodon of a particular tRNA molecule is

A mutant bacterial cell has a defective aminoacyl-tRNA synthetase that attaches a lysine to tRNAs with the anticodon AAA instead of the normal phenylalanine.What would be a potential consequence for a cell in which this happens? Remember that phenylalanine may be encoded by multiple codons.

An experimenter has altered the 3' end of the tRNA corresponding to the amino acid methionine in such a way as to remove the 3' AC.Which of the following statements correctly describes the most likely result of this change?

Which small-scale mutation would be most likely to have the least negative effect on the function of a protein?

Which of the following statements best describes the termination of transcription in bacteria?

Which of the following statements correctly describes alternative RNA splicing?

Which of the following statements correctly defines the most current and complete description of a gene?

What is the function of the release factor in translation?

Using the figure below,identify a 5' → 3' sequence of nucleotides in the DNA template strand for an mRNA coding for the polypeptide sequence Phe-Pro-Lys. Figure 14.6

-The tRNA shown in the figure above has its 3' end projecting beyond its 5' end.Which of the following will occur at this 3' end?