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Last night I came across a question that goes as follows:-

Cells cannot exist without a) cell wall b) cell membrane c) mitochondria d) ribosomes

I am getting confused with option B and option D


If RBC is lacking ribosomes then where the antigen proteins on RBC are coming from ?

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closed as off-topic by Teige, WYSIWYG, J. Musser, Bez, James Feb 24 '15 at 20:51

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The most essential thing for a cell to survive is a membrane. Without a membrane there is no boundary between cell and its surroundings. A selectively permeable membrane is needed for cells (from single celled organisms to elephants and giraffes and whales) to survive. Cells will die quickly on removal of cell membrane.

The RBCs are good example of cells without mitochondria or ribosomes which survive for 120 days.


Please read the article on Erythropoiesis for detailed information on how RBCs form and how they have proteins in their surface.

In short, the RBCs acquire the surface proteins during their formation period in the bone marrow. Inside the bone marrow the premature RBCs have nucleus, ribosomes, mitochondria, etc... and produce all the required structural and functional proteins. On maturing they loose the nucleus and cell organelles and contain only hemoglobin in their cytoplasm.

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  • $\begingroup$ If RBC is lacking ribosomes then where the antigen proteins on RBC are coming from ? $\endgroup$ – Dhruba Banerjee Feb 24 '15 at 17:06
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    $\begingroup$ There is no cell without a membrane :P (A cell by definition has to have a membrane). Self sustaining cells do need ribosomes but they can survive without mitochondria (prokaryotes anyways don't have one and there are eukaryotes without mitochondria such as Entamoeba) $\endgroup$ – WYSIWYG Feb 24 '15 at 17:48
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    $\begingroup$ There exist some accounts of temporary stages that lack a cell membrane. If these represents a form of cell question of definitions. SSee e.g. biomedcentral.com/1471-2180/11/255 $\endgroup$ – fileunderwater Feb 24 '15 at 23:17
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    $\begingroup$ @fileunderwater The statement in that article seems doubtful. First they say "protoplasts" and then they say "without a membrane". Protoplasts are plant cells without walls but they still have membranes. Without a membrane (long enough to be called a stage) the cell would have no boundaries and therefore the definition of a cell no longer holds (more like a cell lysate) $\endgroup$ – WYSIWYG Feb 25 '15 at 5:45
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    $\begingroup$ @WYSIWYG I cannot really evaluate this research, and was just curious about what papers are out there. There are a couple of other articles as well, e.g. ncbi.nlm.nih.gov/pubmed/12111719 and jcs.biologists.org/content/114/11/2009.short. As I said, whether these are cells is a question about how you define a cell. It seems like they survive for ~10h before a new membrane is formed (a "gelatinous envelope" is formed before that though). Quote: "Nucleocytoplasmic aggregates, ... released after injury ... are membraneless structures that can survive in seawater for 10–20 min." $\endgroup$ – fileunderwater Feb 25 '15 at 7:48
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Cells can survive without ribosomes, but they would accumulate damage and be unable to restore worn out or exhausted supplies of any proteins they may require. The ribosome is necessary to be able to perform protein translation from RNA. Thus, if the cell can survive without protein, then it would be able to survive without ribosomes. No known organism that exists today meets that definition, if I am not mistaken. However, at some point, it is theorized that the earliest cells were able to perform replication and metabolism without the use of protein. So, it is likely, but not something that is seen in life today.

Nicholas H. Barton Derek E.G. Briggs Jonathan A. Eisen , David B. Goldstein and Nipam H. Patel.(2010). Evolution. Cold Stone Harbor Laboratory Press.

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  • $\begingroup$ Nicholas H. Barton Derek E.G. Briggs Jonathan A. Eisen , David B. Goldstein and Nipam H. Patel.(2010). Evolution. Cold Stone Harbor Laboratory Press. $\endgroup$ – Liftboard Rider Feb 24 '15 at 17:22

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