Chapter 15 Flashcards
hypothesis showing the direct relationship between genes and enzymes
one gene-one enzyme hypothesis
restatement of this one gene-one enzyme hypothesis, taking into account that some proteins consist of more than one polypeptide and not all proteins are enzyme
one gene-one polypeptide hypothesis
the mechanism by which the information encoded in DNA is made into a complementary RNA copy
transcription
the use of the information encoded in mRNA to assemble amino acids into a polypeptide
translation
the name give by Francis Crick to the flow of information from DNA to RNA to protein
central dogma
The DNA strand that is copied into an RNA molecule during gene transcription
template strand
A gene encoding a protein
protein-coding gene
an RNA molecule that serves as a template for protein synthesis
messenger RNA (mRNA)
the nucleotide information that specifies the amino acid sequence of a polypeptide
genetic code
each 3-letter word (triplet) of the genetic code
codon
a codon that specifies an amino acid
sense codons
the first codon read in an mRNA in translation-AUG
start codon/ initiator codon
A codon that does specify amino acids. the 3 nonsense codons are UAG, UAA, and UGA
stop codons/nonsense codon/termination codon
the feature of the genetic code in which with 2 exceptions, more than one codon represents each amino acid
degeneracy
the sequential nature of the words of the nucleic acid code, with no indicators such as commas or spaces to mark the end of one codon and the beginning of the next
commaless
A feature of the nucleic acid code, with the same codons specifying the same amino acids in all living organisms
universal
the site to which RNA polymerase binds(prokaryotes) or to which general transcription factors bind and recruit RNA polymerase (eukaryotes) for initiating transcription of a gene
promoter
a region of DNA that transcribes a single primary transcript
transcription unit
in transcription, the step in which the molecular machinery that carries out transcription assembles at the promoter and begins synthesizing an RNA copy of the gene. in translation, the step in which the translation components assemble on the start codon of the mRNA
initiation
in eukaryotes, the proteins required for RNA polymerase to initiate transcription or that regulate that process. one class of transcription factors recognizes and binds to the promoter in the area of the TATA box and then recruit RNA polymerase
transcription factor (TF)
an enzyme that catalyzes the assembly of ribonucleotides into and RNA strand
RNA polymerase
in transcription, the step in which RNA polymerase (RNA polymerase II in eukaryotes) moves along the gene extending the RNA chain, with the DNA continuing to unwind ahead of the enzyme. in translation, the step in which the assembled translation complex reads the string of codons in the mRNA one at a time while joining the specified amino acids into the polypeptide
elongation
in transcription, the step in which transcription ends and the RNA transcript and RNA polymerase (RNA polymerase II in the case of eukaryotes) are released from the DNA template. in translation, the step in which the translation complex disassembles after the last amino acid of the polypeptide specified by the mRNA has been added to the polypeptide
termination
in eukaryotes, the proteins required for RNA polymerase to initiate transcription or that regulate that process. one class of transcription factors recognizes and binds to the promoter in the area of the TATA box and then recruit RNA polymerase
transcription factors
specific DNA sequence for a gene that signals the end of transcription of a gene. terminators are common for prokaryotic genes
terminators
a gene encoding an RNA that is not translated; that is, a gene other than a protein-coding gene
noncoding RNA genes
the part of an mRNA between the 5’ end of the molecule and the start codon; this region does not code for amino acids
5’ untranslated region (5’ UTR)
the part of an mRNA between the stop codon and the 3’ end of the molecule; this region does not code for amino acid
3’ untranslated region (3’ UTR)
the primary transcript of a eukaryotic protein-coding gene, which is processed to form messenger RNA
precursor-mRNA (pre-mRNA)
in eukaryotes, a guanine-containing nucleotide attached in a reverse orientation to the 5’ end of pre-mRNA and retained in the mRNA produced form it. on an mRNA is the site where ribosomes attach to initiate translation
5’ cap
sequence near the 3’ end of a eukaryotic gene which, in the pre-mRNA transcript of the gene, specifies where the transcript should be cleaved. once cleaved, a poly(A) tail is added to the 3’ end of the RNA
polyadenylation signal