3 ms·
> In a similar way, every membrane in every cell came from extending and then splitting an existing membrane, again more or less independently of the nucleus.
by zmgsabst 3y ago
> In a similar way, every membrane in every cell came from extending and then splitting an existing membrane, again more or less independently of the nucleus.
Can you elaborate?
As I understand it, the manufacturing of the cell membrane and coordination of splitting with other features (eg, intracellular features that pull it apart) requires the DNA transcription and is regulated by particular genes.
That is, depends on the nucleus.
- angiosperm 3y agoProteins are certainly involved wherever membranes are grown, and proteins are coded for in the nucleus. But the membranes are always there first. No cell anywhere in nature, as far as we know, just makes any membrane from one lipid and then another; membranes are only made by extending an existing membrane.
- zmgsabst 3y agoThe hypothesis is that coding molecules predate cell membranes. So we have “every current cell membrane requires the nucleus” and “the coding portion came first”; nobody is disputing that membranes build on membranes, just pointing out they integrally depend on the nucleus to operate (coding for proteins) — and always have. > again more or less independently of the nucleus Ie, this is wrong.
- angiosperm 3y agoThere was a time when there was no nucleus, and no DNA. But there were membranes and RNA.