Wikipedia:Reference desk/Archives/Science/2019 October 26

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October 26

Bacteria questions.

Do bacteria have an equivalent of sleep?

What do bacteria do for waste, can they eat their own waste, and can they eat the remains of dead bacteria? Assuming they have a mouth.

I know bacteria reproduce by splitting in half, so there must be a point where cutting it in half kills it vs. doesn't kills it. 67.175.224.138 (talk) 02:31, 26 October 2019 (UTC).

The answer to the sleep question is generally "No", but there are some day-night related activities with some bacteria.[1] ←Baseball Bugs ^{What's up, Doc?} carrots→ 03:59, 26 October 2019 (UTC)

In relation to the second question, here's an article which includes the subject.[2] ←Baseball Bugs ^{What's up, Doc?} carrots→ 04:02, 26 October 2019 (UTC)

And for the third, cutting a bacteria in half, supposing you find a cutting object of the relevant size, will always kill it. see Fission_(biology)#Binary_fission for the way it reproduce: this involves the creation of a new cell boundary inside itself, not really a cut Gem fr (talk) 16:23, 26 October 2019 (UTC)

Yes, "slicing" a cell exactly in half would involve rupturing its cell membrane, which kills the cell. This is true of any cell. Bacteria also have a cell wall, and several classes of antibiotics, such as the beta-lactam antibiotics, work by disrupting it, which either kills or weakens the bacteria. Cell division involves splitting the cell membrane and, if applicable, dividing the cell wall, in an orderly fashion. --47.146.63.87 (talk) 07:36, 27 October 2019 (UTC)

It's also likely that only one of the cuts will have a copy of the Circular prokaryote chromosome. So even if the damage could be repaired, only one part would be viable. Nil Einne (talk) 08:30, 27 October 2019 (UTC)

Cellular waste is disposed of either by simple diffusion or active transport. Bacteria aren't much different from your own cells in this aspect. A given bacterium can't "eat" it's own waste; that's what makes it waste, something the cell wants to get rid of. However, something that's waste to one species of bacteria can be food for another. Good examples are fermentation products, which can often be broken down further by other cells given the right conditions. (A familiar fermentation product is ethanol, or "alcohol", though the ethanol that humans consume is produced by yeasts, not bacteria.) --47.146.63.87 (talk) 07:36, 27 October 2019 (UTC)

There may be some exceptions to that, but they are dependent on specific conditions. Under starvation conditions, bacteria (and other organisms) will go through a biochemical pathway that does things like converting ATP/GTP down the pathway to adenine and guanine, which is then released into the surroundings (this could be called "waste"). After the reintroduction of nutrients, the pathway reverses to a salvage pathway that allows the production of ATP/GTP without the expense of de novo synthesis. Under these conditions, the bacteria are essentially "eating their own waste." --OuroborosCobra (talk) 20:25, 29 October 2019 (UTC)

As for sleep, when there's no food around, I assume they become less active, to conserve energy. But this is perhaps closer to hibernation than sleep. SinisterLefty (talk) 05:38, 2 November 2019 (UTC)

Some bacteria will restructure their bodies in a major way under such conditions, see endospore. Icek~enwiki (talk) 09:15, 2 November 2019 (UTC)