White Blood Cell chasing a Bacteria

[Mad Indian]

I have some exposure to image analysis of Natural Killer T Cells, but I have never seen a tail like thing before.

Anyway, do bacteria have a cell membrane and a wall, or only membrane?

Bacteria have cell wall and a cell membrane. They may or may not have capsules. And Natural Killer Tcells dont need anti bodies to kill the Bacteria or virus or tumour cell and it is unique among T-cells that way.

You would have passed your exam?

No I could have used the animation for the Physiology presentation

You didn't use the word "antibody" even once.

Bacteria will be optimised to be eaten by Neutrophil/Macrophages.

And the function of the anti body is not opsonisation alone and antibodies are not the only opsonins, thats why I dint use the word anitbody, though I could have used it, since everyone knows about it.

 

[pmaitra]

Bacteria have cell wall and a cell membrane. They may or may not have capsules.

What is a capsule? (using one of your favourite smileys)

So, are bacteria, therefore, part of the Animal Kingdom?

 

[Mad Indian]

What is a capsule? (using one of your favourite smileys)

The cell capsule is a very large structure of some prokaryotic cells, such as bacterial cells. It is a layer that lies outside the cell wall of bacteria. It is a well organized layer, not easily washed off, and it can be the cause of various diseases. Again from Wiki

It usually consists of polysaccharides, but can be composed of other materials (e.g., polypeptide in B. anthracis)

The capsule is considered a virulence factor because it enhances the ability of bacteria to cause disease (i.e. prevents phagocytosis). The capsule is slippery and fragile, so when a phagocyte tries to phagocytose the bacteria, it can slip away. A capsule-specific antibody may be required for phagocytosis to occur. Capsules also contain water which protects bacteria against desiccation. They also exclude bacterial viruses and most hydrophobic toxic materials such as detergents. There are 14 different capsule types, which each impart their own specific antigenicity. Immunity to one capsule type does not result in immunity to the other types. Capsules also help cells adhere to surfaces.

So, are bacteria, therefore, part of the Animal Kingdom?

Bacteria , in the modern Taxonomy come under a Seperate Kingdom, Kingdom Modera, from wiki

Monera (/məˈnɪərə/ mə-neer-ə) is a kingdom that contains unicellular organisms without a nucleus (i.e., a prokaryotic cell organization), such as bacteria. The kingdom is considered superseded.[1]

The taxon Monera was first proposed as a phylum by Ernst Haeckel in 1866. Subsequently, the taxon was raised to the rank of kingdom in 1925 by Édouard Chatton. The last commonly accepted mega-classification with the taxon Monera was the five-kingdom classification system established by Robert Whittaker in 1969.

Under the three-domain system of taxonomy, which was established in 1990 and reflects the evolutionary history of life as currently understood, the organisms found in kingdom Monera have been divided into two domains, Archaea and Bacteria (with Eukarya as the third domain). Furthermore the taxon Monera is paraphyletic. The term "moneran" is the informal name of members of this group and is still sometimes used (as is the term "prokaryote") to denote a member of either domain.[2]

Despite the fact that most bacteria were classified under Monera, the bacterial phylum Cyanobacteria (the blue-green algae) was not initially classified under Monera, but under Plantae because of the ability of its members to photosynthesise.

But, in the previous two kingdom classification, it was under Plant Kingdom.

 

[pmaitra]

^^

Thanks. That's what I learnt about bacteria, that they were part of the Plant Kingdom, because they have cell wall, like most plant cells.

We also learnt about viruses, being neither dead, nor living. Viruses have always intrigued me. What a remarkable creation.

I am sure you have studied this, but I find the behaviour of the Varicella zoster virus, and the reaction of the human body particularly fascinating.

 

[drkrn]

His argument is right that the staphylococcus is immobile. But what we see there is more of a passive drift than a active mobility I think if it is indeed the actual photography

may be the video is correct.they gave some explanation for the bacterial movement here Fagocitose Neutrófilo.wmv - YouTube