Micro Replication Terms

DNA gyrase

Nics one of the chromosomes to relax the DNA supercoils ahead of the Replisome.

Helicase

Unwinds the double strands of DNA at the replication fork. (Unzips your genes)

Single Strand Binding Proteins

Decorate the lagging strand to prevent it from binding back to the original strand.

DNA primase

Adds a short piece of RNA primer that is complementary to the single-strand piece of DNA. The RNA strands have a 3’ hydroxyl group at the end. Gives DNA polymerases a starting point

DNA Polymerase 3 (leading strand)

Works towards the replication fork, 3’→5’, Continuously laying nucleotides down to create a complementary stand of DNA(3’→5’)

DNA Polymerase 3 (lagging strand)

Works in the opposite direction of the replication fork, makes the new strand of DNA in fragments. Reads the strand 3’→5’.

Okazaki Fragments

Have gaps where the original RNA primer was.

DNA polymerase 1

Responsible for filling the gaps on the Okazaki fragments where the RNA primer was removed. Leaves a gap between the newly put dna by DNA Pol 1 and the dna placed by the DNA Pol 3. (Corrects things)

DNA ligase

Bonds and makes the covalent, phosphodiester bond are to complete the new strand.

TER sites

Found in circular chromosomes. Recognized by Tus proteins that block the progress of the replication fork.

Telomerase

Found in eukaryotes, the ends of the linear chromosomes.

Tau protein

Holds the replisome together

Tus protein

tells the replication machinery that your done At the end of a circular chromosome

dnaA

Origin binding protein that binds to the origin

SeqA

binds to the origin during a 10 minute period, where nothing can happen to the DNA except DNA replication

MreB protein

form filamentous bands around the inside of the cell under cytoplasmic membrane to direct new cell wall to be made at certain locations

FtsI proteins

Transpeptidases that insert new peptidoglycan into expanding cell wall

Transglycosylases

From glycosidic bonds between sugars

Autolysins

Create small openings in existing cell wall

Autolysis

Spontaneous cell lysis

May occur if there is an error in inserting new cell wall material

Bactoprenol

Binds to the peptidoglycan precursor, facilitates transport through the cytoplasmic membrane. Lipid alcohol

Transpeptidation

Uses FtsI to form peptide bonds between pentapeptide of peptidoglycan precursor and tetrapeptide of an existing peptidoglycan unit. Happens between the 4th amino acid of the precursor and the third amino acid of the existing peptide. The 5th amino acid gets removed in the process.

Transglycosylase

Replaces the beta 1,4 glycosidic bond between N-acetylmoramic acid and N-acetylglucosamine on both sides of the precursor

LAG phase

Period of adjustment, when cells get introduced to a new growth medium.

Exponential phase

Cells are dividing (LOG phase)

Stationary phase

Cells stop dividing but are not dying

N=No 2^n

Final number of cells

g=t/n

Generation time

No

Initial number of cells

n

Number of generations

t

Time of exponential growth (either hours, or minutes)

Polycistronic mRNA

any time you have a coding sequence that represents multiple genes in RNA

Operon

DNA sequence were multiple genes are represented continuously without being interrupted by a terminator

Open reading frame

What gets translated, start codon to stop codon