Bacterial Molecular Biology: Transcription, Translation, and DNA Replication

What is the purpose of Tetracycline

prevents the amino acid frrom entering the A site

What does Rifamycin do

Inhibits the bacterial RNA polymerase. This interupts transcription

WHat does Streptomycin affect

the 30s ribosomal subunit which causes the ribosome to misread mRNA codons. Leads to nonfunctioning proteins and cell death.

What does Chloramphenocol do?

inhibits peptide bond formations in the 50s subunit. which in turn inhibits protein synthesis.

What do sigma factors do

recognizes and binds promoter sequences, if there are no sigma factors then transcription cannot occur

What is Transcription

Going from DNA to RNA

What is Translation

mRNA to proteins

What enzyme fills the gaps after RNA primers are removed

DNA ligase

What enzyme seals the remaining nicks in DNA fragments

DNA Ligase

DNA Gyrase is included in

Both Teanscription and replication

Archae resemble bacteria in...

coupling of transcription and translation bc they are similiar in physical makeup. and they lack a membrane.

Plasmids are found in

archaea, bacteria, and eukaryotic microbes

If no mRNA is made why woul that be

the promoter is inhibited

What are important things used in Transcription

RNA Polymerase and sigma factors.

Translation is

Decoding the RNA to assemble proteins

Mesenger rna (mRNA)

encodes proteins

Transfer RNA (tRNA)

Shuttles amino acids

Small RNA (sRNA):

regulates transcription or translation

tmRNA

Frees Ribosomes stuck on damaged mRNA

Catalytic RNA

carriws out enzymic reactions

What does RNA polymerase do

synthesizes the strand of RNA from DNA template in Transcription

What is a Promoter

A sequence of DNA upstream of the transcription start site

What is the RNA polymerase composed of

Sigma factor and Core polymerase

Three phases of Transcription

Initiation, elongation, Termination

What does the sigma factor do

help the core enzyme detect the promoter in signaling the beginning of the gene in transcription

What is Ecolis Sigma and what does it do

They have sigma 70 that recognizes consensus sequences at -10 and -35 positions

What do sigma factors compete for?

the same core polymerase

In transcription what removes positive supercoils

Topoisomerases like Gyrase

Rifamycin B

selectively binds to the bacterial RNA pol inhibiting transcription

Actinomycin D

Non selectively bonds to DNA, inhibits transcription

Translation

mRNA is converted to an amino acid sequence

What are Codons

messages from rna that arrange into a sentence of triplets of nucleotides in TRANSLATION

What do ribosomes do in Translation

Machines that read the language of mRNA and translate it into protein.

What is the Genetic code

61 specify amino acids, 3 stop codons

What is tRNA involved with

Translation

what are the two functional regions of the tRNA

Anticodon which specifies the amino acid. 3' acceptor that binds the amino acid

What is the P site

It is where a tRNA carrying the first amino acid is paired ith the start codon on mRNA. This is in the initiation Phase of Translation

What is the A site

The site in elongation of translation where the second codon of the mRNA pairs with a tRNA carrying the second amino acid.

Where do gram negative proteins need to export proteins

completely out of the cell.

What does BLAST stand for

Basic Local Alignment Search tool

What does PCR do?

Amplifirs specific genes.

What are the components of PCR

DNA sample, Primers, Nucleotides, Taq polymerase, Mix Buffer, PCR tube.

How do we purify PCR products

Gel electrophoresis . Other column purification kits.

What is Agarose gel Electrophoresis

used to anylize the DNA fragments obtained by treatment with restriction enzymes or PCR reaction.

In DNA replication what is DNaA

the initiator protein

In DNA repication what is DNaB

helicase. unwinds the double helix

What does Topoisomerase IV do

seperates concatenated chromosomes in DNA repication

What does DNA Pol I do in DNA repliation

replacrs RNA primer with DNA

How do Plasmids replicate?

Rolling circle mechanism

Ehat do plasmids need to help them replicate

Host proteins (single stranded binding protein)

In DNA replication where does initiation occur

oriC

In DNA replication where does elongation occur

replication forks

In DNA replication where does termination occur

occurs at the terminus (ter)