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Why are cells small?

burrito.bio

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Re: Why are cells small?

#41

Post by vasco »

DaveSchmindel wrote: post #10
chasil wrote: post #2

Not all are? Largest eukaryote: https://en.wikipedia.org/wiki/Valonia_ventricosa largest prokaryote: https://en.wikipedia.org/wiki/Thiomargarita_namibiensis

> Cell sizes are not fixed, however, even within a single species. Cells often swell as they increase their production of proteins and metabolites in preparation for division. This is in line with biology’s only rule: namely, there are exceptions to every rule! > Case in point: a giant bacterium called Thiomargarita magnifica can extend about one centimeter in length, so large that it can be seen by the naked eye. It…

> This is in line with biology’s only rule: namely, there are exceptions to every rule!

Nice paradox

Re: Why are cells small?

#42

Post by teravor »

chasil wrote: post #2

Not all are? Largest eukaryote: https://en.wikipedia.org/wiki/Valonia_ventricosa largest prokaryote: https://en.wikipedia.org/wiki/Thiomargarita_namibiensis

    > The entire cell contains several cytoplasmic domains, with each domain having a nucleus and a few chloroplasts.
it reinvented being multi-cellular

Re: Why are cells small?

#43

Post by teravor »

fluoridation wrote: post #31
kayo_20211030 wrote: post #5

> A simplistic answer is that evolution has made each cell the size best suited to its function. Yeah. That's probably it. Really, it probably is the right answer.

That just kicks the can forward one step. What parameters control the optimal size of a given cell?

there is likely evolutionary pressure against large cell size (selfish genes; larger cell takes energy away from replication, provides more opportunity for infiltration by other genes, fewer gene backups in other cells, etc) while occupying a niche puts pressure to be a certain size. it lands somewhere in the middle.

Re: Why are cells small?

#45

Post by gus_massa »

hatthew wrote: post #33
NoMoreNicksLeft wrote: post #24

Earlier quoted context omitted.

This almost feels like cheating. Why not count hair follicles with hair attached then?

In addition to what mbauman said, hair follicles and the hair itself are not single-cell. I can't immediately find the composition and average cell size, but even a long and thick strand of hair is less than 2 orders of magnitude larger than the largest neurons. I doubt any individual hair cell is very large.

I agree, except the Squid Gian Axon https://en.wikipedia.org/wiki/Squid_giant_axon that can "1mm diameter and almost 1m long" https://www.understandinganimalresearch.org.uk/using-animals...

Re: Why are cells small?

#46

Post by lmm »

ssivark wrote: post #26
chasil wrote: post #2

Not all are? Largest eukaryote: https://en.wikipedia.org/wiki/Valonia_ventricosa largest prokaryote: https://en.wikipedia.org/wiki/Thiomargarita_namibiensis

Isn't the ovum supposed to be a single cell? Eggs of various species can be substantially larger than this.

Yes. I remember reading that Ostrich eggs are the largest single cells (in terms of mass/volume; Blue Whale nerve cells are longer).

Re: Why are cells small?

#48

Post by [deleted] »

lmm wrote: post #46
ssivark wrote: post #26

Earlier quoted context omitted.

Isn't the ovum supposed to be a single cell? Eggs of various species can be substantially larger than this.

Yes. I remember reading that Ostrich eggs are the largest single cells (in terms of mass/volume; Blue Whale nerve cells are longer).

[deleted]

Re: Why are cells small?

#49

Post by api »

teravor wrote: post #42
chasil wrote: post #2

Not all are? Largest eukaryote: https://en.wikipedia.org/wiki/Valonia_ventricosa largest prokaryote: https://en.wikipedia.org/wiki/Thiomargarita_namibiensis

> The entire cell contains several cytoplasmic domains, with each domain having a nucleus and a few chloroplasts. it reinvented being multi-cellular

It uses container based virtualization under a single host kernel instead of VM based virtualization.

Re: Why are cells small?

#50

Post by [deleted] »

hatthew wrote: post #18
limbero wrote: post #7

Nitpick maybe, but I don't think oocytes are the largest cells, it pretty much has to be some sort of neuron. A sensory neuron for eg. someplace in the foot will be almost as long as the person is tall, and even if the neuron is extremely thin, it's gotta beat the oocyte for volume.

Some back of the envelope math says this is true. A conservative estimate for the size of an alpha motor neuron axon is 10μm diameter and 1m long, which already puts it over an order of magnitude larger than the 4,000,000µm³ oocyte quoted in the article.

[deleted]
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