Chapter 14 Vocab Flashcards
5’ cap
A modified form of guan9ine nucleotide added onto the end of a pre mRNA molecule
A site
One of a ribosomes three binding sites for tRNA during translation. The A site holds the tRNA carrying the next amino acid to be added to the polypeptide chain
Alternative RNA Splicing
A type of eukaryotic gene regulation at the RNA processing level in which different mRNA molecules are produced from the same primary transcript, depending on which RNA segments are treated as exon and which as introns
Aminoacyl-tRNA synthase
An enzyme that joins each amino acid to the appropriate tRNA
Anticodon
A nucleotide triplet at one end of a tRNA molecule that base pairs with a particular complementary codon on an mRNA molecule
Codon
A three nucleotide sequence of DNA or mRNA that specifies a particular amino acid of termination signal, the basic unit of the genetic code
Deletion
A mutational loss of one or more nucleotide pairs from a gene
E site
One of a ribosomes three binding sires for tRNA during translation. The E site is the place where discharged tRNA’s leave the ribosome
Exon
A sequence within a primary transcript that remains in the RNA after RNA processing, also refers to the region of DNA from which this sequence was transcribed
Frameshift mutation
A mutation occurring when nucleotides are inserted in or deleted from a gene and the number inserted or deleted is not a multiple of three, resulting in the improper grouping of the subsequent nucleotides into codons
Gene expression
The process by which information encoded in DNA directs the synthesis of proteins, or in some cases, RNAs that are not translated into proteins and instead functions as RNAs
Insertion
A mutation involving the addition of one or more nucleotide pairs to a gene
Intron
A noncoding, intervening sequence within a primary transcript that is removed from the rancript during RNA processing, also refers to the region of DNA from which this sequence was transcribed.
Messenger RNA
A type of RNA, synthesized using a DNA template, that attaches to ribosomes in the cytoplasm and specifies the primary structure of a protein.
Missense mutation
A nucleotide pair substitute that results in a codon that comes for a different amino acid
Mutagen
A chemical or physical agent that interacts with DNA AND CAN CAUSE A MUTATION
Mutation
A change in the nucleotide sequence of an organisms DNA or in the DNA or RNA of a virus
Nonsense mutation
A mutation that changes an amino acid codon to one of the three stop codons, resulting in a shorter and usually non functional protein
Nucleotide pair substitution
A type of point mutation in which one nucleotide in a DNA strand and its partner in the complementary strand are replaced by another apri of nucleotides
P Site
On of a ribosomes three binding sites for tRNA during translation. The P sire holds the tRNA carrying the growing polypeptide chain
Point mutation
Idk
Poly-A-tail
A sequence of 50-250 adenine nucleotides added onto the 3’ end of a pre mRNA molecule
Primary transcript
An initial RNA transcript from any gene, also called pre mRNA when transcribed from a protein coding gene
Promoter
A specific nucleotide sequence in the DNA of a gene that binds RNA polymerase, positioning it to start transcribing RNA at the appropriate place.
Reading frame
On an mRNA, the triplet grouping of ribonucleotides used by the translation machinery during polypeptide synthesis
Ribosomal RNA
RNA molecules that, together with proteins, make up ribosomes, the most abundant type of RNA
Ribosome
A complex of rRNA and protein molecules that functions as a site of protein synthesis in the cytoplasm; consists of a large subunit and a small subunit. In eukaryotic cells, each subunit is assembled in the nucleolus
Ribozyme
An RNA molecule that functions as an enzyme, such as an intron that catalyzes its own removal during RNA splicing.
RNA Polymerase
An enzyme that links ribonucleotides into a growing RNA chain during transcription, based on complementary binging to nucleotides on a DNA template strand
RNA Processing
Modification of RNA primary transcripts, including splicing out of introns, joining together of exon, and alternation of the 5’ and 3’ ends.
Silent mutation
A nucleotide pair substitution that has no observable effect on the phenotype; for example, within a gene, a mutation that results in a codon that codes for the same amino acid.
Spliceosome
A large complex made up of proteins and RNA molecules that splices RNA by interacting with the ends on an RNA intron, releasing the intron and joining the two. Adjacent exon
TATA Box
A DNA sequence in eukaryotic promoters crucial in forming the transcription inititation complex.
Template strand
The DNA strand that provides the pattern, or template, for ordering, by complementary base pairing, the sequence of nucleotides in an RNA transcript
Terminatior
In bacteria, a sequence of nucleotides in DNA that marks the end of a gene and signals RNA polymerase to release the newly made RNA molecule and detach from the DNA
Transcription
The synthesis of RNA using a DNA template
Transcription factor
A regulatory protein that binds to DNA and affects transcription of specific genes
Transcription initiation complex
The completed assembly of transcription factors and RNA polymerase bound to a promoter
Transcription unit
A region of DNA that is transcribed into an RNA molecule
Transfer RNA
An RNA molecule that functions as a trasnlateor between nucleoid acid and protein languages by picking up a specific amino acid and carryin it to the ribosome, where the tRNA recognizes the appropriate codon in the mRNA
Translation
The synthesis of a polypeptide using the genetic information encoded in an mRNA molecule. There is a change of “language” from nucleotides to amino acids.
Triplet code
A genetic information system in which a series of three nucleotide long words specifies a sequence of amino acids for a polypeptide chain.
Wobble
Flexibility in the base pairing rules in which the nucleotide at the 5’ end of a tRNA anticodon can for. Hydrogen bonds with more than one kind of base in the third position (3’ end) of a codon
