cell bio gene controll

early gene control

occurs in the nucleus regulates the transcription and rna processing. prevents unnecessary energy usage

late gene control

occurs in the cytoplasm includes regulation of transcription localization of mrna proteins and ribosomes, and control of rna degradation, enables regulation while still having proteins and stuff on hand

operons

segments of rna in prokaryotes, contains promotor operator and a group of related genes.

promotor in operon

binds rna polymerase to the strand

operator

where regulatory proteins are bound

negative regulation in prokaryotes

repressor binds to operon, prevents transcription unitl removed by a ligand

positive regulation in prokaryotes

activator binds to operon, enables transcription, deactivates gene when removed by a ligand

enzymatic access control

control of transcription in synthesis by controlling access to the dna

dna acetylation

condenses the dna

dna deacetylation

loosens dna

dna methylation

blocks transcription

differential protein expression

expression of one gene increases or decreases the translation of other genes. How cells get differentiated. 

Gel electrophoresis

dna is places in a gel on the negatively charged end and then moves to the positively charged end. the longer dna segments travel more farther cuz their more attracted to the positive charge

Southern Blott method

after gel electrophoresis a nitrocellulose membrane is put on top of the gel. afterwards the dna is denatured and a probe is added which makes it appear as a dark spot on an x-ray

PCR

DNA is put into an environment with a lot of excess nucleotides ligases and polymerases than heated to denature it then cooled causing it to reform into new strands using the nucleotides and enzymes several times to exponentially increase the amount of dna strands present. 

dna cut and pasting

endonuclease enzymes and ligases can be used t effectively cut and paste segments of dna.

how to study the affect of genes

you either disable or hyper enable the gene and see what the effect on the organism is compared to the normal phenotype.

CRISPR-CAS9

a specially made ra binds to the target dna site triggering it to get cut by the CAS9 enzyme afterwards the cell repairs the dna wising non-homologues end repair damaging the genome by removing part of the sequence

RNA interference

a double stranded rna enters the cell and gets chopped up by a slicer enzyme. these small siRNAs then bind to mrna in the cytoplasm which marks it for destruction.

gene modification using plasmids

using slicing enzymes a gene is inserted into the plasmid which also contains an antibiotic resistance gene. these bacteria are then put in a petri dish with antibiotics in it so only the bacteria that have the new plasmic in their genome survive. once you isolate the bacteria with the plasmids the bacteria can be inserted into eukaryotic cells.