Ch 4 Hw Part 2

Examine the figure below, which depicts one stage in the process of translation in a eukaryote. What will happen when the ribosome shifts one codon further on the mRNA, assuming the next codon is NOT a stop codon? (Select all that apply.)

-The tRNA carrying the polypeptide will be in the P site. -A new tRNA will bind to the ribosome. -The tRNA that was carrying the polypeptide will be ejected from the ribosome

An mRNA molecule has a sequence 5'- CAGAUCUAAUGCUUAUCGGAU-3'. When translated in a laboratory setting in which translation can be initiated anywhere along the molecule, how many reading frames are possible?

3

A double-stranded DNA molecule is being transcribed, only part of which is shown below. If the molecule is translated from left to right, one of the nucleotides shown in bold would be the first transcribed in this small molecule. 5'-ATGATCGGATCGATCCAT-3' 3'-TACTAGCCTAGCTAGGTA-5'

5'-AUGAUCGGAUCGAUCCAU-3'

Assuming that transcription and translation both proceed from left to right, which is the correct orientation of the DNA template, the RNA transcript, and the protein product?

DNA template 3'- ......... -5' RNA transcript 5'- ......... -3' Protein product H2N- ....... -COOH

Because there are three different possible reading frames in a messenger RNA molecule, most mRNAs can be translated in a cell into three different proteins.

False

If the RNA transcript resulting from the DNA sequence above is present in the mRNA and translated codon by codon from one end to the other, which of the following polypeptides would correspond to this part of the mRNA? (Use Table 4.1 to answer this question.)

NH2 - Met-Ile-Gly-Ser-Ile-His -COOH

During elongation of translation, the growing polypeptide is transferred from the tRNA in the _____ site of the ribosome to the tRNA in the _____ site as a peptide bond is formed between the growing polypeptide and the newest tRNA.

P; A

Imagine that a primary RNA transcript from your favorite eukaryotic gene was processed incorrectly, such that it has no 5' cap. What would be the result?

The initiation complex would fail to form properly, and translation would not occur.

In what order does a charged tRNA move through the sites of a ribosome

The tRNA binds with the A site, then is moved to the P site, then the E site as the ribosome shifts.

Multiple ribosomes can be translating protein from a single mRNA simultaneously in a eukaryote, but the mRNAs being translated are monocistronic.

True

The energy to carry out the movement of a ribosome comes from GTP.

True

Which of the following codons is capable of terminating translation?

UGA, UAG, UAA

When a charged tRNA is about to bind to the vacant A site of a ribosome, where is the growing polypeptide?

in the P site

Examine the figure below, which depicts one stage in the process of translation in a eukaryote. Where will the tRNA be when the large subunit of the ribosome joins the complex?

in the P site of the ribosome

Transcripts of rRNA genes are concentrated in the:

nucleolus.

A consecutive sequence of codons following a start codon is called a:

reading frame.

Which one of the following types of proteins interacts directly with a stop codon?

release factor

Ribosomes in prokaryotes and eukaryotes are:

similar in structure and translate using the same genetic code.

In eukaryotes, the AUG codon that starts translation is:

the AUG nearest the 5' cap on the mRNA.