The main physical function of teichoic acid 1With it's negative electric charge,teichoic acid can combine with Mg2+and other positive ions which present under circumstances and increase these ions'concentration which ensures the requirement of maintaining hi-activity of some compound enzyme that subsist on the cell thecrs. 2and to some G(+)(such as group A asstreptococcus),with the help of teichoic acid(mainly theca teichoic acid )they can conglutinate hosts. 3special exterior antigen is endowed to G(+)4It's the special adsorbing embracer of some phagocytes
The main physical function of teichoic acid : ①With it’s negative electric charge, teichoic acid can combine with Mg2+ and other positive ions which present under circumstances and increase these ions’ concentration which ensures the requirement of maintaining hi-activity of some compound enzyme that subsist on the cell thecrs. ②and to some G(+)(such as group A asstreptococcus) ,with the help of teichoic acid(mainly theca teichoic acid )they can conglutinate hosts. ③special exterior antigen is endowed to G(+)④It’s the special adsorbing embracer of some phagocytes
2.The cell wall structure of G-: Characteristic:the layer of peptide polysaccharid is very thin (only 2~3nm).there is another theca outside the layer of peptide polysaccharid and its components is complex. The wall ply of G is thinner than G*and its mechanical intensity is frailer than G+'s
2.The cell wall structure of G- : Characteristic：the layer of peptide polysaccharid is very thin (only 2~3nm) .there is another theca outside the layer of peptide polysaccharid and its components is complex. The wall ply of Gis thinner than G+ and its mechanical intensity is frailer than G+ ’s
(1)The layer of peptide polysaccharid Characteristic (take coliform for instance): the layer of peptide polysaccharid is thin (2~3nm) .The third of the end of tetrapeptide is not L-Lys,but M- DAP. .No special peptide bridge,the connection between its back- and -forth 2 monomer is D-carboxyl of lactamine which is the forth amino acid of a former telopeptide and M-carboxyl of DAP which is the third amino acid of a back telopeptide straightly.(It only can form a peptidoglycan meshwork of estrangement and bad mechanical intension.)
(1) The layer of peptide polysaccharid ： Characteristic （take coliform for instance）： •the layer of peptide polysaccharid is thin (2~3nm) •The third of the end of tetrapeptide is not L-Lys，but M－ DAP. •No special peptide bridge, the connection between its backand –forth 2 monomer is D-carboxyl of lactamine which is the forth amino acid of a former telopeptide and M-carboxyl of DAP which is the third amino acid of a back telopeptide straightly. (It only can form a peptidoglycan meshwork of estrangement and bad mechanical intension.)
(2)Ectoblast: Characteristic: a.It is the special structure of G bacteria cell wall,which is at the most Outer of the wall. b.The chemic compositions are lipopolysaccharide phosphatide and some kinds of ectoblast albumens. Function:a.Control the cell permeability b.improve the concentration of Mg2+ c.decide the antigenicity of cell wall. d.lipoid A is the basis of anatoxin
(2) Ectoblast： Characteristic: a.It is the special structure of G- bacteria cell wall,which is at the most Outer of the wall. b. The chemic compositions are lipopolysaccharide , phosphatide and some kinds of ectoblast albumens. Function：a. Control the cell permeability b. improve the concentration of Mg2+ c. decide the antigenicity of cell wall. d. lipoid A is the basis of anatoxin
Porin O-specific Braun's lipoprotein side chains Lipopolysaccharide Outer membrane Periplasmic space and peptidoglycan Plasma Phospholipid membrane Peptidoglycan Integral protein G-exosporium
G- exosporium