ch 12 gene expression at the molecular level

how many distinct aminoacyl-tRNA synthetases does each cell make

-60

directly produced from the transcription of a eukaryotic gene

pre-mRNA

transcription begins near a site in the DNA called the

promoter

molecule exhibits self-splicing

rRNA and tRNA

where the most common eukaryotic ribosome carries out its function

cytosol

intervening sequences transcribed but not translated into protein are

introns

incorrect statement about RNA polymerase in bacteria

it catalyzes the addition of nucleotides to the 5' end of a growing RNA strand

released when an aminoacyl-tRNA synthetase charges a tRNA

AMP and pryophosphate

protein involved in synthesizing messenger RNA in eukaryotes

RNA polymerase I

________ is to transcription as _________ are to translation

RNA polymerase; ribosomes

how many nucleotides are contained in a single codon

3

RNA sequence produced from DNA template strand 3'-TACAATGTAGCC-5'

5'-AUGUUACAUCGG-5' (3')

enables a single gene to encode two or more polypeptides that are different in their amino acid sequence

alternative splicing

N-terminus refers to the presence of this at the 5' end of a polypeptide

amino group

enzyme catalyzes the attachment of amino acids to tRNA molecules

aminoacyl-tRNA synthetase

because more than one codon can specify the same amino acid, the genetic code is said to be

degenerate

a single gene always encodes for an enzyme

false

all enzymes are proteins

false

as part of the transcriptional unit, regulatory sequences are the sites where RNA polymerase and transcription facotrs bind to regulate transcription

false

because of the abundance of ribosomes, translation is NOT an energy costly process for the cell

false

in eukaryotes, 40S and 60S combine to form a 100S ribosome

false

tRNA contains the genetic code for producing a polypeptide

false

the cells of every organism make only a few different tRNA molecules encoded by the same gene

false

translation is a relatively slow process

false

organized unit of DNA sequences that enables a segment of DNA to be transcribed into RNA and ultimately results in formation of a functional product

gene

processes of transcription and translation are collectively known as

gene expression

incorrect statement about RNA processing in eukaryotes

introns are excised out of pre-mRNA to produce the mature mRNA

would occur if a cell's splicesomes were mutated so they no longer functioned normally

introns would remain in the mature mRNA

bond that holds the amino acids of a growing polypeptide chain together during the elongation stage of translation

peptide

NOT a component of the translation machinery

protein polymerase

factors needed to recognize the stop codon and disassemble the translation machinery

release factors

correct sequence of events for the initiation and elongation steps of translation

small ribosomal subunit binds to mRNA, initiator tRNA binds to start codon on mRNA, large ribosomal subunit binds, tRNA entry and peptidyl transfer reaction, translocation of ribosome and release of tRNA

serves as the "translator" or intermediary between an mRNA codon and an amino acid

tRNA

false statement about tRNA

tRNAs can be spliced by splicesomes

true statement about the 5' cap and mRNA processing

the 5' cap is added to the pre-mRNA by splicesomes

basic feature of transcription NOT shared by prokaryotes and eukaryotes

the complexity of protein components involved in transcription is similar for both prokaryotes and eukaryotes

function of the poly-A tail

the poly-A tail increases mRNA stability in eukaryotes

incorrect statement about the mRNA start codon

the start codon is usually GGA

region of structural gene contains the information that specifies an amino acid sequence

transcribed region

process that produces mRNA from DNA

transcription

protein that influences the ability of RNA polymerase to transcribe genes

transcription factors

products of nonstructural genes and are therefore never translated

transfer RNA and ribosomal RNA

what process would a defective ribosome have the most detrimental effect on

translation

DNA is used as a template to make mRNA, which contains the information to make a polypeptide

true

RNA polymerase II of eukaryotes always requires more than one general transcription factor to initiate transcription

true

more than one codon can specify the same amino acid

true

the termination of translation occurs when a release factor recognizes the stop codon

true

molecule provides energy for translation

GTP

anticodon sequence of 5'-AUG-GGC-ACU-CAU-3'

3'-UAC-CCG-UGA-GUA-5'

5'-ACU-UUC-ACU-AUG-UUU-UUA-UCC-UCC-ACU-CCU-UGA-3' results in

Met-Phe-Leu-Ser-Ser-Thr-Pro