Exam 17: From Gene to Protein

Use the following model of a eukaryotic transcript to answer the next few questions. 5' UTR E₁ I₁ E₂ I₂ E₃ I₃ E₄ UTR 3' -Which of the following is a useful feature of introns for this model?

When the ribosome reaches a stop codon on the mRNA, no corresponding tRNA enters the A site. If the translation reaction were to be experimentally stopped at this point, which of the following would you be able to isolate?

The following questions refer to this table of codons. -A peptide has the sequence NH₂-phe-pro-lys-gly-phe-pro-COOH. Which of the following sequences in the coding strand of the DNA could code for this peptide?

Which of the following nucleotide triplets best represents a codon?

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

The process of translation, whether in prokaryotes or eukaryotes, requires tRNAs, amino acids, ribosomal subunits, and which of the following?

Which of the following mutations is most likely to cause a phenotypic change?

A frameshift mutation could result from

Which of the following types of mutation, resulting in an error in the mRNA just after the AUG start of translation, is likely to have the most serious effect on the polypeptide product?

The following question refers to this figure of a simple metabolic pathway: -A mutation results in a defective enzyme A. Which of the following would be a consequence of that mutation?

During splicing, which molecular component of the spliceosome catalyzes the excision reaction?

RNA polymerase in a prokaryote is composed of several subunits. Most of these subunits are the same for the transcription of any gene, but one, known as sigma, varies considerably. Which of the following is the most probable advantage for the organism of such sigma switching?

What is the function of GTP in translation?

Garrod hypothesized that "inborn errors of metabolism" such as alkaptonuria occur because

Use the following information to answer the next few questions. A transfer RNA (#1) attached to the amino acid lysine enters the ribosome. The lysine binds to the growing polypeptide on the other tRNA (#2) in the ribosome already. -Which component is not directly involved in translation?

The following information should be used for the next few questions. A part of an mRNA molecule with the following sequence is being read by a ribosome: 5' CCG-ACG 3' (mRNA). The following charged transfer RNA molecules (with their anticodons shown in the 3' to 5' direction) are available. Two of them can correctly match the mRNA so that a dipeptide can form. -The anticodon loop of the first tRNA that will complement this mRNA is

In the structural organization of many eukaryotic genes, individual exons may be related to which of the following?

Which small-scale mutation would be most likely to have a catastrophic effect on the functioning of a protein?

Use this representation to answer the following questions. DNA template strand 5' ____________________________ 3' DNA complementary strand 3' ____________________________ 5' -Given the locally unwound double strand above, in which direction does the RNA polymerase move?

A particular triplet of bases in the template strand of DNA is 5' AGT 3'. The corresponding codon for the mRNA transcribed is