BIO 326R 1st Edition Lecture 13 Outline of Last Lecture I. Translationa. componentsi. Ribosomesii. tRNAb. initiationc. elongationd. terminationOutline of Current Lecture I. Cell Division- Binary FissionII. Cell biology of bacteriaa. Green fluorescent proteinb. FtsZc. MinC, MinD, MinEd. MreBe. Dividing on multiple planesCurrent LectureBinary fission- Replicate DNA - Divide into 2 cellso StepsThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute. Have at least 1 chromosome in each cell Divides by cytokinesis- Formation of septum= separation of cellso DNA replication takes ~40 minutes E. coli can divide in 20 minutes because it begins a second replication forkbefore the first one endso Bacteria genome per cell can differ Faster growing I cells generally have more genomes Affects transcription (gene expression)- Genes around origin are present at higher levels in faster growing cells- E. coli has evolved to have genes that need to be highly expressed placed near the origino Binary fission=> two equal progeny (cells) happens by: Elongates (grows) Form septum (finds the mid cell) Form cell walls SeparateCell biology of bacteria- Green fluorescent protein (GFP)o 2008 Nobel Prize in Chemistry (Chalfie, Shimumura, Tsien)o Absorb a lower wavelength (blue) and emit a slightly higher wavelength (green)o Isolated from jelly fish (Aequorea Victoria)o 27 KDa protein, cytoplasmic- Subcellular localization of proteinso Location within the cello Can follow proteins if associated with a fluorescent like GFP GFP fuses to protein of interest Problems:- Sometimes protein of interest doesn’t function anymore- Generally only works in cytoplasm (not periplasm)- FtsZo Like tubulin (involved in making microtubules)o The cytoskeletono Form a rind at septum, contracts, and pinches cello Filamentous temperature sensitiveo How does it find the middle of the cell/ MinC, MinD, MinE- Labeled with GFP- Allows to find the middle of the cell- Oscillates back and forth to each end of the cell, spending little time in the middle, and senses where to middle is MinC= prevents FtsZ polymerization- Forming polymers of FtsZ to form the ring MinD= cytoplasmic membrane protein that recruits MinC to membrane before oscillation- FtsZ associates with membrane- MreBo Shape determining factoro Forms spiral throughout cello Attached to membrane that forms infrastructure to form rod shaped bacteriao Not present in cocci If MreB is deleted, it will be cocci- Bacteria can divide on multiple planeso One plane Ex: E. coli , streprococcuso Two planes Ex: micrococcus (tetrad structure)o All planes Ex: stapholococcus (clusters of
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