Chapter 6- Microbial Genetics Flashcards
(27 cards)
What is DNA replication
Flow from one generation to the next during cell division
What is DNA recombination
Flow from one cell to another in the same generation
What is gene expression
Transcribed and translated DNA to produce proteins needed for cellular function
DNA replication is …
Semiconservative (one parent strand and one daughter strand)
DNA polymerase III can only synthesize in …
5’ to 3’ direction
What strand is synthesized continuously
The leading strand
What strand is synthesized in small pieces (Okazaki fragments) that are eventually hooked together
The lagging strand
How is the fidelity of DNA replication accomplished
- Base paring
2. Proof
DNA polymerase III and I can detect incorrect nucleotides that are not complementary and remove them by chewing back the new strand from 3’ end
3’ to 5’ exonuclease activity
What is transcription
The synthesis of a complementary strand of RNA
What is the enzyme for transcription
RNA polymerase (protein)
What is the enzyme for translation
RNA (in ribosome)
Core enzyme of RNA polymerase
αββ’ω
Holoenzyme of RNA polymerase
αββ’ω PLUS σ
What subunit of RNA polymerase is the one that recognizes the promoter
Sigma subunit
When there is more then one codon per amino acid
Degeneracy
What amino acids are the exception of degeneracy
Methionine and tryptophan
Start codon
AUG
Stop (nonsense) codons
UAA, UAG, UGA
How does 30S subunit binds to mRNA
By recognizing Shine-Dalgarno (SD) sequence
How is transcription and translation in prokaryotes
Coupled
What is an Operon
Prokaryotic transcriptional units whose expression is controlled by a single regulator sequence
When RNA polymerase transcribes a long mRNA encoding more then one polypeptide what is it called
Polycistronic RNA
What is negative transcription
When a regulatory protein inhibits transcription when it binds DNA.
