Naked Science Forum

Life Sciences => Cells, Microbes & Viruses => Topic started by: grasscells on 03/07/2005 05:25:46

Title: Cells are like humans!!!
Post by: grasscells on 03/07/2005 05:25:46
Cells are like humans, all they want to do is reproduce, AND QUICK!!!

If cells could speak, they would be the next closest brother to a human!!![:o)]

SOCOM II BABY!
Title: Re: Cells are like humans!!!
Post by: chris on 03/07/2005 22:47:38
That's not entirely true. There are plenty of quiescent, resting, cells in the body, including stem cells, that are not continuously dividing. For instance, differentiated nerve cells are 'post-mitotic' and don't divide throughout life. Similarly, adult skeletal muscle, which consists of a syncitium of many cells merged together, does not divide. New muscle can be formed from stem cells (myoblasts) within the muscle body, but the mature cells are non-dividing.

Chris

"I never forget a face, but in your case I'll make an exception"
 - Groucho Marx
Title: Re: Cells are like humans!!!
Post by: grasscells on 08/07/2005 03:02:31
ok fine, well the majority
Title: Re: Cells are like humans!!!
Post by: moore4u on 12/08/2005 12:32:02
Actually, cells DO talk (communicate).

Glyconutrients are the alphabet for cellular communication that enable the body to perform the many complicated functions for health such as immune system modulation, NK cell enhancement, and inter/intra-cellular communication. Glyconutrients overall importance cannot be overstated. The terrain of our body is weaker than optimal if there are insufficient sugars to provide for efficient communication and self-regulation.
Title: Re: Cells are like humans!!!
Post by: DrN on 06/09/2005 22:33:39
what on earth do glyconutrients have to do with cell division?????? or is that just the longest 'signature' in the history of the forum?

found some interesting research (Goldman lab) where they say differentiated muscle fibres can actually dedifferentiate and become individual myoblasts again, so even muscle cells can divide (apparently)! supposedly part of the regeneration mechanism seen in newts etc.
Title: Re: Cells are like humans!!!
Post by: rosy on 07/09/2005 09:02:02
Cells communicate in lots of ways... not just the cells in our bodies, which communicate not just with their neighbours but also, via the blood stream, with cells all around the body (that's what hormones are for), but also many types of unicellular organisms communicate with others of the same type- google for quorum sensing.
Title: Re: Cells are like humans!!!
Post by: Ylide on 02/10/2005 12:57:10
Quorum sensing is way cool.  I have a Scientific American where they interview the woman who isolated the compound used by bacteria (all kinds of varied species) to "communicate" with each other.  It's the only biomolecule I've ever seen that uses boron!



This message brought to you by The Council of People Who Are Sick of Seeing More People
Title: Re: Cells are like humans!!!
Post by: another_someone on 15/10/2005 04:54:00
quote:
Originally posted by grasscells

Cells are like humans, all they want to do is reproduce, AND QUICK!!!

If cells could speak, they would be the next closest brother to a human!!![:o)]

SOCOM II BABY!


I think the simile is valid, but not taken to its logical conclusion.

Certainly, cells are designed for reproduction, and it is an important part of their life cycle, but then, cells, just as humans, suppress that part of their nature most of the time.

A cell that reproduces uncontrollably would be regarded as a cancerous cell, just as a human that attempts to reproduce without regard for the right (socially acceptable) conditions would be regarded as a criminal (e.g. a serial rapist, probably incestuous, and a pedophile - or more accurately, a hebephile, since true pedophilia would not lead to reproduction).

There is also the fact that many humans actually choose not to reproduce, or to constrain their reproduction, for economic and other social reasons.  The simplest to understand from an evolutionary perspective is the situation of the maiden aunt, who may help look after nephews and nieces.  Since her sibling's children will share much of her own DNA, the maiden aunt is still substantially trying to propagate her own DNA, even though she is not herself reproducing.

By comparison, all the cells in a multicellular organism will share 100% of their DNA, and so there is even more logical reason for the cells to behave as maiden aunts to other cells.
Title: Re: Cells are like humans!!!
Post by: DrN on 09/11/2005 23:12:32
The 'maiden aunt' is a pretty good analogy. really must dig out my Richard Dawkins books again.

Are cells programmed so that division is the natural state? it seems like the cell is generally geared up for division until stopped by expression of certain cell cycle inhibitor proteins. mutations in these proteins are what often causes the uncontrolled proliferation in cancer. the 'off' switch is damaged.

there is also a lot of cell death, so that all these reproducing cells take the place of all the dying cells, again, much like in a human population.

Going back to Richard Dawkins, he takes this even further back and suggests that the genes are the ones that are trying to divide, in this model the actual cell is just an inert carrier.
Title: Re: Cells are like humans!!!
Post by: another_someone on 10/11/2005 05:11:43
quote:
Originally posted by fishytails

The 'maiden aunt' is a pretty good analogy. really must dig out my Richard Dawkins books again.

Are cells programmed so that division is the natural state? it seems like the cell is generally geared up for division until stopped by expression of certain cell cycle inhibitor proteins. mutations in these proteins are what often causes the uncontrolled proliferation in cancer. the 'off' switch is damaged.

there is also a lot of cell death, so that all these reproducing cells take the place of all the dying cells, again, much like in a human population.

Going back to Richard Dawkins, he takes this even further back and suggests that the genes are the ones that are trying to divide, in this model the actual cell is just an inert carrier.



I think this is where the analogy reaches its limits.

The problem is that when a human reproduces, it is clear who is the parent and who is the child, and the parent may then go on to having several children – in other words, it is clear that an individual can choose to have zero or more children.

When a cell divides, it has two daughter cells – who is the parent and who is the child in this scenario – are they not both children, and the parent is now dead?

As you say, whether a cell reproduces or not is determined by its environment and its programming, but it cannot start and stop reproducing, it can only reproduce once.  What you could rightly say is that a particular cell line continues to reproduce until it reaches a point where the combination of environment and programming causes it to cease reproduction.

I don't know that I would regard the cell as in any way inert – the cell is an expression of the genome, you cannot have one without the other.

The interesting difference is whether one should talk about survival of the gene, or survival of the genome (the aggregate package of genes).