MGY377H1 Lecture Notes - Lecture 21: Quorum Sensing, Periplasm, Pilus
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At lo(cid:449) (cid:272)ell de(cid:374)sit(cid:455) the(cid:455) are(cid:374)"t (cid:272)o(cid:373)pete(cid:374)(cid:272)e, (cid:271)ut at higher (cid:272)ell de(cid:374)sities the(cid:455) ha(cid:448)e higher (cid:272)o(cid:373)pete(cid:374)(cid:272)e. This is a quorum sensing system with numerous components. Theres a signaling protein known as csp and its processed and csp is released, and it can then be taken back up by the same bacteria. All the bacteria are secreting quorum sensing moleucles, and as the cell density increases, they have a bigger effect because the concentration of the cells and these molecules are higher. When the conc is high, theres a re(cid:272)eptor (cid:272)alled co(cid:373)d that"s e(cid:454)pressed a(cid:374)d co(cid:373)d a(cid:272)ti(cid:448)ates co(cid:373)e (cid:449)hi(cid:272)h tra(cid:374)s(cid:272)ri(cid:271)es ge(cid:374)es like. In gram+ bacteria, theres about 50 binding sites on the surface of the cell for dna. Once the dna has bound, the dna is degraded outside of the bacterium, and the singke stranded dna is pulled into the cell, and the ssdna is integrated into the genome.