Multiple Choice Final Questions

The template for protein synthesis is

a mRNA strand

In prokaryotic RNA synthesis

inverted-repeat sequences in the DNA being transcribed can lead to termination

The enzyme principally responsible for RNA synthesis in E. coli

is a mutli-subunit enzymes

What category of RNA carries amino acids for the process of translation?

tRNA

In the wobble phenomenon, the base that wobbles is found in

the tRNA

RNA synthesis begins at the base in the DNA sequence designated by what number?

+1 plus one

How many codon are known for each amino acid

1 to 6 depending on the nature of the amino acid

At which position on tRNA is the wobble base of the triplet anticodon?

1'st position (5' letter)

Which is not associated with bacterial promoters? A. transcription start site B. the Pribnow box C. The -35 element D. 3' anti-terminator

3' anti-terminator

How many codons are possible in a system in which a sequence of three bases specifies a single amino acid?

64

Which of the following offers the best description of a Pribnow box? A. A promoter consensus sequence located at approximately -35 B. A promoter consensus sequence located at approximately -10 C. A sequence forming a hairpin loop signaling the termination of transcription D. A sequence immediately surrounding the start site of transcription

A promoter consensus sequence located at approximately -10

What provides the energy for rho-dependent chain termination?

ATP hydrolysis distinct from any incorporation into the chain

Aminoacyl-tRNA syntheses are involves in which step of translation?

Activation

At what point does the sigma subunit of RNA polymerase released from the core enzyme?

After transcription begins and about 10 nucleotides have been added to the RNA chain

A tRNA was determined to have the following anticodon sequence: 3'-GAI-5' (I represents the base hypoxanthine) Which of the following codons can form base pairs with anticodon? A. 5'-CUA-3' B. 5'-CUC-3' C. 5'-CUU-3' D. All of these

All of these

As in RNA and DNA synthesis, the synthesis of proteins follows the following steps, except: A. Activation of monomers B. Initiation C. Elongation D. Termination C. All of these are involves in all polymer synthesis

All of these are involved in all polymer synthesis (Activation of monomers, initiation, elongation, and termination)

Initiation of RNA biosynthesis involves A. Recognition of the promoter region by the alpha subunit of RNA polymerase B. Conversion of the close-promoter complex to the open-promoter complex C. Binding of one of the alpha subunits of RNA polymerase to each strand of DNA D. incorporation of four pyrimidine nucleotides in succession

Conversion of the close-promoter complex to the open-promoter complex

The majority of protein synthesis occurs in the

Cytoplasm

Using the genetic code, indicate which polypeptides would be synthesized if poly (UGG) were used as a synthetic mRNA? A. poly (gly) B. poly (trp) C. poly (trp-val-gly) D. poly (trp), poly (val), poly (gly)

D. poly (trp), poly (val), poly (gly)

Which of the following correctly describes a difference between RNA and DNA polymerases? A. RNA polymerases usually do not need a template, while DNA polymerases do B. DNA polymerases usually require a primer, while most RNA polymerases do not C. RNA polymerases usually synthesize introns, while DNA polymerases synthesizes cistrons. D. RNA polymerase polymerize 5' to 3' while DNA polymerases polymerize 3' to 5' E. None of these

DNA polymerases usually require a primer, while most RNA polymerases do not

Chain termination occurs, in vivo, when

Either a hairpin loop forms or rho catches up with transcription stalled by a hairpin loop

The end of the new mRNA molecule in E. coli usually terminates a string of A's (T/F)

False

Wobble allows a single codon to code for more than one amino acid (T/F)

False

What type of assay using tRNAs and ribosomes enabled complete determination of the genetic code?

Filter binding assays

Inosine or hypoxanthine can wobble with all the following bases except

Inosine can wobble with all of these bases A, C, T, U

Which of the follow is not a key advantage of wobble in the codon-anticodon reaction? A. It allows for fewer tRNAs in the cell B. It allows for making more than one protein from the same coding sequence C. It allows for a certain amount of mutation in the mRNA without affecting the protein sequence D. All of these are advantages of wobble.

It allows for making more than one protein from the same coding sequence

What is the function of the sigma subunit of RNA polymerase in E. coli?

It recognizes promoters where transcription should begin

Which of the following is not a property of the sigma subunit? A. It tells the RNA polymerase where to sit down B. It helps point the RNA polymerase in the proper direction C. It causes the RNA polymerase to bind tightly to the DNA D. It stays with the RNA polymerase throughout synthesis

It stays with the RNA polymerase throughout synthesis

The genetic code is said to be degenerate. This means that

Many of the amino acids are coded for by different codons

Exceptions to the universality of the genetic code been observed in

Mitochondria and 16 other organisms, including some algae and fungi

Which of the following is not an advantage of degeneracy in the genetic code? A. More than one amino acid can bind to a tRNA B. Each tRNA can bind to more than one codon C. Most codons can bind to more than one tRNA D. Fewer tRNA molecules are needed

More than one amino acid can bind to a tRNA

Consensus sequences are A. Sequences that are invariant throughout the DNA B. Sequences required for transcription to occur C. Sequences that have many bases in common D. Sequences that lie far upstream of the core promoter

Sequences that have many bases in common

Which of the following statements concerning RNA transcription is false? A. The DNA strands become separate during synthesis B. Synthesis of RNA is as accurate as synthesis of DNA C. The template strand is read in the 3' --> 5' direction D. All 4 ribonucleotides are required. E. A primer is required for RNA synthesis

Synthesis of RNA is as accurate as synthesis of DNA

Which of the following is not part of the core promoter? A. the transcription start site B. The pribnow box (-10) C. the -35 region D. The UP element

The UP element

How do the core enzyme and the holoenzyme of RNA polymerase differ in E. coli?

The holoenzyme includes the sigma subunits, the core enzyme does not

The promoter site is A. the start site for transcription in DNA B. the binding site for regulatory proteins that stimulate transcription C. the general region of DNA downstream from the start site D. the site on DNA at which RNA polymerase binds to initiate transcription E. None of these

The site on DNA at which RNA polymerase binds to initiate transcription

What is the need for a primer in transcription?

There is none

At which position on the mRNA is the wobble base of the triplet codon?

Third position (3' letter)

What provides the energy for the conversion form the open complex to chain elongation?

Torsional stress built into the separating DNA strands

Which of the following statements concerning RNA transcription is false? A. The reals of pyrophosphate from a nucleoside triphosphate drives the reaction B. RNA is synthesized from the 5' end to the 3' end C. DNA to RNA base pairing includes A to U and G to C D. Transcription requires the use of a primer

Transcription requires the use of a primer

What amino acids have unique codons?

Trp, met

Transfer RNAs contain an anticodon loop meant to match (base pair) with a codon on an mRNA (T/F)

True

Wobble allows each codon to interact with more than one tRNA (T/F)

True

Which of the following codons does not code for an amino acid? A. AUG B. UAA C. CAU D. GUU E. All of these code for an amino acid

UAA

Which of the following statements concerning the genetic code is false? A. It is based on triplets B. It is non-overlapping C. commas are used D. It is degenerate

Commas are used

What is the maximum number of amino acids that can be specified by a codon consisting of a sequence of two bases?

16

Minor differences in the consensus sequence for RNA polymerase ...

Can be exploited to vary the amount of mRNA which is synthesized from that gene

Which of the following best describes the order of events at the promoter? A. Open complex --> closed complex --> transcription initiation B. Closed complex --> open complex --> transcription initiation C. Open complex --> transcription initiation --> closed complex D. Transcription initiation --> open complex --> closed complex

Closed complex --> open complex --> transcription initiation

Which of these terms does not describes the DNA strand used to direct RNA synthesis? A. Template strand B. Coding strand C. Antisense strand D. Negative or - strand E. All of theses describes the DNA strand used to direct RNA synthesis

Coding strand