Exam Gene to proteins

Refer to the figure above. What would the anticodon be for a tRNA that transports phenylalanine to a ribosome?

AAA

Which one of the following, if missing, would usually prevent translation from starting?

AUG codon

Codons are three-base sequences that specify the addition of a single amino acid. How do eukaryotic codons and prokaryotic codons compare?

Codons are a nearly universal language among all organisms

Which of the following mutations would likely be most dangerous to a cell?

Deletion of one nucleotide

Which of the following best describes the significance of the TATA box in eukaryotic promoters?

It is the recognition site for a specific transcription factor.

What must occur before a newly made polypeptide is secreted from a cell?

Its signal sequence must target it to the ER, after which it goes to the Golgi.

Once researchers identified DNA as the unit of inheritance, they asked how information was transferred from the DNA in the nucleus to the site of protein synthesis in the cytoplasm. What is the mechanism of information transfer in eukarotes?

Messenger RNA is transcribed from a single gene and transfers information from the DNA in the nucleus to the cytoplasm, where protein synthesis takes place.

Which one of the following statements about RNA processing is true?

Ribozymes may function in RNA splicing.

In an experimental situation, a student researcher inserts an mRNA molecule into a eukaryotic cell after she has removed its 5' cap and poly-A tail. Which of the following would you expect her to find?

The molecule is digested by enzymes because it is not protected at the 5' end.

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

UUC

Which of the following DNA mutations is most likely to damage the protein it specifies?

a base-pair deletion

A ribozyme is _____.

an RNA with catalytic activity

According to the central dogma, what molecule should go in the blank? DNA → _____ → Proteins

mRNA

Refer to the metabolic pathway illustrated above. If A, B, and C are all required for growth, a strain that is mutant for the gene-encoding enzyme A would be able to grow on medium supplemented with _____.

nutrient B only

Refer to the metabolic pathway illustrated above. If A, B, and C are all required for growth, a strain mutant for the gene-encoding enzyme B would be able to grow on medium supplemented with _____.

nutrient C only

Use the following information to answer the question(s) below. 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. tRNA Anticodon Amino Acid GGC CGU UGC CCG ACG CGG Proline Alanine Threonine Glycine Cysteine Alanine The dipeptide that will form will be _____.

proline-threonine

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. The consequence of this for the cell will be that _____.

proteins in the cell will include lysine instead of phenylalanine at amino acid positions specified by the codon UUU

Transcription in eukaryotes requires which of the following in addition to RNA polymerase?

several transcription factors

In eukaryotic cells, transcription cannot begin until

several transcription factors have bound to the promoter.

Which of the following is the first event to take place in translation in eukaryotes?

the small subunit of the ribosome recognizes and attaches to the 5' cap of mRNA