Exam 14: Gene Expression: From Gene to Protein

Which of the following types of mutation, resulting in an error in the mRNA just after the 3ʹ AUG start codon, is likely to have the most serious effect on the polypeptide product?

What must happen to a newly made polypeptide before it can be secreted from a cell?

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

Which of the following experimental procedures is most likely to speed up mRNA degradation in a eukaryotic cell?

When translating secretory or membrane proteins, ribosomes are directed to the ER membrane by

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

In eukaryotic cells, transcription cannot begin until

What is the function of the release factor in translation?

Figure 14.5 -The tRNA shown in Figure 14.5 has its 3' end projecting beyond its 5' end. What will occur at this 3' end?

Which of the following is a function of a poly-A tail in mRNA?

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

Figure 14.5 -What type of bonding is responsible for maintaining the shape of the tRNA molecule in Figure 14.5?

Use the following model of a eukaryotic transcript to answer the question. E1-4 refer to the exons and I1-3 refer to the introns in the pre-mRNA transcript. 5' UTR E1 I1 E2 I2 E3 I3 E4 UTR 3' Suppose that exposure to a chemical mutagen results in a change in the sequence that alters the 5' end of intron 1 (I1). Which of the following results might occur?

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

In order for a eukaryotic gene to be engineered into a bacterial colony to be expressed, what must be included in addition to the coding exons of the gene?

A particular triplet of bases in the coding sequence of DNA is AAA. The anticodon on the tRNA that binds the mRNA codon is

Figure 14.3 -Given the locally unwound double strand in Figure 14.3, in which direction does the RNA polymerase move?

Garrod's information about the enzyme alteration resulting in alkaptonuria led to further understanding of these types of metabolic pathways in humans. Phenylketonuria (PKU) occurs when another enzyme in the pathway is altered or missing, resulting in a failure of phenylalanine (phe) to be metabolized to another amino acid: tyrosine. Tyrosine is an earlier substrate in the pathway altered in alkaptonuria. How might PKU affect the presence or absence of alkaptonuria?

The anticodon of a particular tRNA molecule is

Which of the following does not occur in prokaryotic gene expression, but does occur in eukaryotic gene expression?