Unit 4- Bacterial Genetics+Epidemiology Flashcards
(170 cards)
Define Lariate
A ring of intron segments that have been spliced out of mRNA by enzymes
5’ Guanosine Cap Function
protects the nascent mRNA from degradation and assists ribosomes in binding during translation
Spliceosome (Function)
RNA-Protein complex that recognizes the exon-intron junctions and enzymatically cuts through them (RNA Splicing)
Poly-A Tail Function
@ the 3’ end, the Poly A Tail is added when elongation is complete. It protects mRNA from enzyme degradation
Role of Transcription factors and RNA Polymerase in transcription
A Family of proteins that function in a multi-subunit complex that can bind to the promoter on DNA or directly to RNA Polymerase. They can activate or repress transcription
Sense Strand of a gene
The strand that holds the coding sequence for a particular gene
The antisense strand of a gene
the strand that holds the complement of the coding sequence for a gene
Define Codon
A Sequence of 3 nucleotides that together form a unit of genetic code in a DNA or RNA molecule
Define Anticodon
a sequence of 3 nucleotides forming a unit of genetic code in a tRNA molecule corresponding to a complementary codon in mRNA
Structure of ribosomes
Made of rRNA (Ribosomal RNA), site of translation, form ribosome-protein complex
A Site on the Ribosome
Aminoacyl site, which adds the amino acid to the polypeptide chain
P Site on the Ribosome
Where the Peptidyl tRNA is formed in the ribosome
E Site on the Ribosome
Exit site for the polypeptide chain
How are Amino Acids linked togehter by the ribosome?
Translation: Amino Acids opposite the codon (tRNA) will align at the A, P, and E Site to create a polypeptide chain out of amino acids.
Wobble in the Genetic Code
The Genetic Code’s third codon is usually coding for the same amino acid, relating to the degeneracy of the code
Point Mutation
Single-nucleotide switches/replacements
Silent Mutation
Codes for the same amino acid with a nucleotide switch
Missense Mutation
Cause another Amino Acid to be coded
Frameshift Mutation
Can cause a reading frame offset and cause a nonsense or missense mutation
Nonsense Mutation
Causes a stop codon to be generated
Back Mutation
Reverses a mutation from its abberant state back to its normal state
Ames Test
A test to determine the mutagenic activity of chemicals by observing whether they cause mutations in simple bacteria
Define Operon
A section of DNA that contains one or more structural genes along with a corresponding operator gene that controls transcription
Regulator in an operon
Turns the operon on/off in response to lactose and glucose levels