文档介绍：Peptidoglycan Synthesis Transport of peptidoglycan precursors across the cytoplasmic membrane to the growing point of the cell wall
The transpeptidation reaction that lead to the final cross-linking of two peptidoglycan chains Penicillin inhibits this reaction
The majority of motile prokaryotes move by means of flagella
Flagellar Arrangements
Peritrichous
Polar
Lophotrichous
The E. coli Flagellar
Structure
Bacterial Behavior Chemotaxis, Phototaxis, and Other Taxes
Prokaryotes encounter gradients of physical and chemical agents in nature, and the motility machinery in the cell is designed to respond in a positive or negative way to these gradients by directing the movement of the cell either toward or away from the signal molecule, respectively.
Such directed movements are called TAXiS.
Chemotaxis: a response to chemicals.
Phototaxis: a response to light.
Chemotaxis in Bacteria
Chemotaxis is the movement of anism toward (an attractant) or away from (a repellent) a chemical.
The Chemotaxis Process
(a) In the absence of a chemical attractant the cell swims randomly in runs, changing direction during tumbles.
(b) In the presence of an attractant runs e biased, and the cell moves up the gradient of the attractant.
Mechanism of Chemotaxis
MCPs: methyl-accepting chemotaxis proteins
Phototaxis
Accumulation of the phototrophic bacterium at light wavelengths at which its pigments absorb.
Phototaxis of an entire colony toward the light source on the right.