Microbial genetics Flashcards
Extra chromosomal unit of heredity. It carries with it code for toxicity and antibiotic resistance. Replicates on its own
Plasmid
What are the 3 components of DNA nucleotides
Phosphate group, deoxyribose sugar, adenine-guanine-thymine-cytosine bases
Functions as a structural part of nucleic acid
Phosphate
Function is to express genetic information
Nitrogen bases
This RNA is the site of protein synthesis
rRNA
This RNA carries amino acids to the ribosome during protein synthesis
tRNA
Template for protein synthesis
mRNA
2 parental strands of DNA are copied into 2 daughter strands
DNA replication
Each cell receives 1 parental strand and 1 daughter strand
semiconservative replication
Enzyme that synthesizes 2 nucleotide strands
DNA polymerase (POL III)
Enzyme that removes any mistaken base pairs
DNA exonuclease (POL I)
Enzyme that seals gaps and joins the 2 strands together
DNA ligase
Group of protein that recognize the origin of replication
DNA A Protein
Unwind the double helix ahead of replication fork
helicase
Remove supercoils that interfere with the further unwinding of the double helix
DNA topoisomerase
Leading strand is synthesized continuously in a _____________ direction by DNA polymerase
5’ to 3 ‘ direction
Synthesizes a short RNA primer which is extended by DNA polymerase III
RNA polymerase (primase)
Enzyme responsible for making mRNA
RNA polymerase
Helps the core enzyme attach more tightly to specific deoxyribonucleotide sequence of promoter region
sigma factor
Binding of RNAP holoenzyme to template at promoter site
Template binding
First nucleotide (usually a purine) associates with initiation site on B subunit of enzyme
Initiation
Successive residues are added to 3’ terminus with sequence dictated by base pairing rules
Elongation
This must occur to provide access for appropriate base pairing
DNA unwinding
Recognizes the termination signal. An ATP-dependent RNA-DNA helicase
rho factor
start codon for bacteria
formyl methionine
blocks assembly of the ribosome during initiation
streptomycin
blocks peptide bond formation during elongation
Chloramphenicol