Talk:Chemotaxis

NOR

Although user Kohlasz may be an expert in the area, I find at least one instance of a contribution that violates WP:NOR. Also, a figure under the subheading In the mirror of publications uploaded by user Kohalasz is misleading in the sense that it has not been published in a peer reviewed journal, although, the reader is lead to believe it has.

ßråΔ

^talk

CCW And CW rotation

Has anyone noticed that the picture showing CCW and CW rotation of the E. Coli are actually two pictures of CW (Clockwise) rotation? Just that the arrows are at different positions but the direction is the same. —Preceding unsigned comment added by 201.20.120.114 (talk) 20:11, 19 September 2007 (UTC)

Please note the presence of solid and dotted lines on the figure! This makes sense of the positions of the arrows, too. For sure, the figure is schematic and only helps to understand that when the direction of rotation is changed - itself the swimming behaviour is also significantly altered. Best regards from Kohlasz 21:22, 23 September 2007 (UTC)

Number of flagella

In the article on Helicobacter it is mentioned that they have 4-6 flagella, whereas in this article it is mentioned that they only have one. Which is correct?Kghose 01:52, 5 October 2005 (UTC)

Dear Kghose, Please check the two pages again. In Helicobacter page mentioned by you there is no 4-6 flagella cited (not even one!!!), while in 'Chemotaxis' you can find that E.coli has 4-6 flagella. This is correct. The number of flagella depends on the type of cell. You should also consider that there is another component of the cell 'pilus' which helps the cell to stick on the surface, however, it is not an active moving component. Taking together from 0-several the number of flagella is correct if the cell type is correct. Thank you for your help around page Chemotaxis! Best regrds from Kohlasz 21:12, 23 September 2007 (UTC)

sperm...?

is this how sperm move? 86.9.73.56 23:34, 9 March 2006 (UTC)

Not really, sperm cells are propelled by the regular beat of their eukaryiotic flagellum. A eukaryiotic flagellum is not to be confused with a bacterial flagellum.

Sperm cells of many species show chemotaxis, an area of active research (see work by Eisenbach, Brokaw, Kaupp, ...).--91.67.241.244 (talk) 21:05, 3 February 2008 (UTC)

Grammar and spelling corrections

I have taken the liberty of cleaning up the English grammar and spelling. Somebody with more knowledge of the subject should review the changes to make sure the content is still correct, since I know very little about this subject, and I had to take a guess at the original meaning in a couple of places.

In addition, the following sentence is still hard to parse in English, and I didn't want to guess as to the meaning:

Chemoattractant moiety of fMLF elicited in neutrophil granulocytes and monocytes.

--Salsa man 22:40, 23 September 2006 (UTC)

Misconception about wide-range sensitivity in bacterial chemotaxis

There is a misconception in the paragraph dedicated to E. Coli chemotaxis, it states:

"However, the methylation system alone cannot account for the wide range of sensitivity that bacteria have to chemical gradients."

That is not correct, the integral feedback created by the methylation pathway is the only responsible for wide range sensitivity, as it allows the system to maintain its high sensitivity operating point over a wide range of backgrounds. more about this can be found in [1]. The article further states:

"Additional regulatory mechanisms such as receptor clustering and receptor-receptor interactions also modulate the signalling pathway."

It is known today that receptor interactions and clustering do not modulate the signaling pathway. It is true however that the total value of the high sensitivity (not the range on which it is maintained) is enhanced by mechanisms such as receptor-receptor interactions, receptors clustering, and the ultrasensitive response of the flagellar motor to the CheY-P signal [2,3].

Because of this I will slightly edit those lines.

[1] Effects of Adaptation in Maintaining High Sensitivity over a Wide Range of Backgrounds for Escherichia coli Chemotaxis

   Biophysical Journal, Volume 92, Issue 7, Pages 2329-2337
   B. Mello, Y. Tu

[2] Receptor clustering and signal processing in E. coli chemotaxis

   V Sourjik - TRENDS in Microbiology, 2004

[3] An Ultrasensitive Bacterial Motor Revealed by Monitoring Signaling Proteins in Single Cells

   Philippe Cluzel, 1* Michael Surette, 2 Stanislas Leibler 1  —Preceding unsigned comment added by 83.82.70.144 (talk) 11:11, 4 February 2010 (UTC)