Prokaryotes vs Eukaryotes

II. RNA modification

5” cap chemically speaknig

The movie – yes there is a movie http://vcell.ndsu.nodak.edu/animations/mrnaprocessing/movie.htm

III Bacteria genetics Binary fission

Prokaryotic variation in genetic make-up Mutations Genetic recombination Transformation Transduction Conjugation

Transformation

Transduction

Conjugation

IV. Control of metabolic pathways Two ways Vary the activity of the enzymes (inhibit them or promote their ability) – feedback inhibition pathways Vary the # of enzymes present – regulate enzyme production at the gene expression level

B. Gene regulation in bacteria OPERONS! Need to know that an operon is a section of DNA that contains genes for a protein Need to know the parts and players

Ex 1 – Lac Operon

Ex 2 Tryptophan operon

A closer look at the parts A) promoter – site on DNA where RNA polymerase can bind and begin transcription B) operator – the “on/off” switch, located between promoter and structural genes C) structural genes – genes that code for a protein

Important players Repressor – a protein that when active will bind to the operator thus blocking transcription Regulatory gene – the DNA sequence that codes for the repressor protein Co-repressor – a molecule that attaches to an inactive repressor and makes it active Inducer – a molecule that attaches to an active repressor and makes it inactive

How they work together Negative regulation Positive regulation

Negative regulation Two examples Lac operon Tryptophan operon – best animation link