Bio 1 Chapter 17 Review

Put the following events of elongation in prokaryotic translation in chronological order. 1. Binding of mRNA with small ribosomal subunit 2. Recognition of initiation codon 3. Complementary base pairing between initiator codon and anticodon of initiator tRNA 4. Base pairing of the mRNA codon following the initiator codon with its complementary tRNA 4. Attachment of the large subunit

1, 2, 3, 5, 4

Use the following information to answer the question 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. The anticodon loop of the first tRNA that will complement this mRNA is

3'GGC5'

Put the following events of bacterial transcription in chronological order. 1. Sigma binds to the promoter region 2. The double helix of DNA is unwound, breaking hydrogen bonds between complementary strands 3. Sigma binds to RNA polymerase 4. Sigma is released 5. Transcription begins

3, 1, 2, 5, 4

Use this model of a eukaryotic transcript to answer the following question(s). E = exon and I = intron 5' UTR E1 I1 E2 I2 E3 I3 E4 UTR 3' Which components of the previous molecule will also be found in mRNA in the cytosol?

5' UTR E1 E2 E3 E4 UTR 3'

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

5' cap or AUG codon

If the sequence in the coding strand of DNA for a particular amino acid is 5'AGT3' then the anticodon on the corresponding tRNA would be ________.

5'ACU3'

You want to engineer a eukaryotic gene into a bacterial colony and have it expressed. What must be included in addition to the coding exons of the gene?

A bacterial promoter sequence

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

A single nucleotide deletion in an exon coding for an active site

During elongation, which site in the ribosome represents the location where a codon is being read?

A site

During elongation, RNA polymerase has three prominent channels, or grooves. These channels provide sites for all of the following EXCEPT ____________.

A site for the exit of the diphosphates removed from the nucleotide triphosphates

How does termination of translation take place?

A stop codon is reached

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

AAA

There are 61 codons that each specify the addition of a specific amino acid, and 3 stop codons for which there is no corresponding amino acid. However, there are only about 40 tRNA molecules, representing 40 anticodons. How is that possible?

An anticodon forms hydrogen bonds with the codon; It must match the first two bases of the codon but is less specific with respect to the third base

Use this model of a eukaryotic transcript to answer the following question(s). E = exon and I = intron 5' UTR E1 I1 E2 I2 E3 I3 E4 UTR 3' When the spliceosome binds to the transcript shown above, it can attach ____________.

At certain sites along an intron

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

Codons are nearly universal language among all organisms.

The anticodon of a particular tRNA molecule is ____________.

Complementary to the corresponding mRNA codon

Use the following information to answer the question(s) below. 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. Where does tRNA #2 move to after this bonding of lysine to the polypeptide?

E site

In comparing DNA replication with RNA transcription in the same eukaryotic cell, only DNA replication _______.

Incorporates the entire template molecule in the prodcut

As scientists were unraveling the mysteries associated with transcription and translation in eukaryotes, they discovered there was not a one-to-one correspondence between the nucleotide sequence of a gene and the base sequence of the mRNA it codes for. They proposed the genes-in-pieces hypothesis, How can the genes-in-pieces hypothesis be explained?

Introns are noncoding segments of DNA that are present in the initial transcript, but are removed by splicing

In the figure associated with this question, what is the function of the ACC sequence at the 3' end?

It attaches to the amino acid

In the figure associated with this question, what is the function of the AGU on the loop of the tRNA?

It base pairs with a codon of mRNA

What is the function of the group of amino acids on the RNA polymerase, called the rudder?

It moves template and non-template strands of DNA through channels inside the enzyme.

Eukaryotes have three nuclear RNA polymerases. The primary function of RNA polymerase II is transcription of ___________.

Protein-coding genes

The enzyme complex associated with DNA in the associated figure is ___________.

RNA polymerase

In Eukaryotes, there are several different types of RNA polymerase. Which type is involved in transcription of mRNA for globin protein?

RNA polymerase II

Use this model of a eukaryotic transcript to answer the following question(s). E = exon and I = intron 5' UTR E1 I1 E2 I2 E3 I3 E4 UTR 3' Suppose than an induced mutation removes most of the 5' end of the 5' UTR of an mRNA. What is most likely to happen?

Removal of the 5' UTR also removes the 5' cap and the mRNA will quickly degrafe

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

Ribozymes may function in RNA splicing

The ribosome-binding site of prokaryotes is also known as the ___________________.

Shine-Dalgarno sequence

The tRNA shown with the previous question has its 3' end projecting beyond its 5' end. What will occur at this 3' end?

The amino acid binds covalently

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' bases AC. Which of the following hypotheses describes the most likely result?

The amino acid methionine will not become covalently bound

What ensures that the correct amino acid is added during translation?

The anticodon of a properly formed aminoacyl tRNA

In an experimental situation, a student researcher inserts an mRNA molecule into a eukaryotic cell after she has removed it s5' 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

Which molecule or reaction supplies the energy for polymerization of nucleotides in the process of transcription?

The phosphate bonds in the nucleotide triphosphates that serves as substrates

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

The rules for the base pairing between the third base of a codon and tRNA are flexible

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

The small subunit of the ribosome recognizing and attaching to the 5' cap of mRNA

How are RNA hairpin turns related to transcriptional termination in E. coli?

The turns are formed from complementary base pairing and cause separation of the RNA transcript and RNA polymerase

Which of the following statements is TRUE about protein synthesis in prokaryotes?

Translation can begin while transcription is still in progress

The figure associated with this question represents a 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

What is responsible for termination of transcription in eukaryotic protein-coding genes?

a polyadenylation, or poly(A), signal

A ribozyme is ________________.

an RNA with catalytic activity

Ribosomes can attach to prokaryotic messenger RNA _____________.

before transcription is complete

David Pribnow studied the base sequences of promoters in bacteria and bacterial viruses. He found two conserved regions in these promoters (the -10 box and the -35 box). These two regions of the promoter _____________.

bind the sigma subunit that is associated with RNA polymerase

Which of the following processes is central to the initiation of of transcription in bacteria?

binding of sigma to the promoter region

Accuracy in the translation of mRNA into the primary structure of a polypeptide depends on specificity in the ____________.

binding of the anticodon and the attachment of amino acids to tRNAs

Which of the following occurs in prokaryotes but not in eukaryotes?

concurrent transcription and translation

What type of bonding is responsible for maintaining the shape of the tRNA molecule shown in the figure above?

hydrogen bonding between base pairs

Translation requires ____________.

mRNA, tRNA, and rRNA

Translation directly involbes

mRNA, tRNA, ribosomes, and GTP

Use the following information to answer the question(s) below. 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 described enters the exit tunnel in the large subunit of the ribosome?

newly formed polypeptide

Refer to the figure associated with this question. The mRNA is smaller than the length of the DNA that codes for it because _________.

post-transcriptional modification removes the introns

A mutant bacterial cell has a defective aminoacyl-tRNA synthetase that attaches a lysine to tRNAs with 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 pheylalanine at amino acid positions specified by the codon UUU

What molecules in the spliceosome catalyze the intron removal reactions?

ribozymes

In eukaryotic cells, transcription cannot being until _________.

several transcription factors have bound to the promoter

In E. Coli., if RNA polymerase is missing ________, then transcription initiation would not occur at the appropriate initiation sites.

sigma

Death cap mushrooms produce a substance called alpha-amanitin. Alpha-amanitin efficiently blocks synthesis of mRNA, but not of tRNA or rRNA, in eukaryotic organisms. This is possible because alpha-amanitin efficiently interferes with ________.

the action of RNA polymerase II, but not RNA polymerase I or III

There should be a strong positive correlation between the rate of protein synthesis and ____________.

the number of ribosomes

Some viruses can be crystalized and their structures analyzed. One such virus is yellow mottle virus, which infects beans. This virus has a single-stranded RNA genome containing about 6300 nucleotides. Its capsid is 25-30 nm in diameter and contains 180 identical capsomeres. If the yellow mottle virus begins its infection of a cell by using its genome as mRNA, which of the following would you expect to be able to measure?

translation rate

Once a peptide bond has been formed between the amino acid attached to the tRNA in the P site and the amino acid associated with the tRNA in the A site, what occurs next?

translocation