About microscopic forms of life, including Bacteria, Archea, protozoans, algae and fungi. Topics relating to viruses, viroids and prions also belong here.
My bad, they don't actually have the translation equipment, they have genes (ORFs) to produce certain pieces of translation equipment.
"Protein translation" probably refers to the translation of single stranded RNA into amino acids, which is usually just referred to as "translation" in biology. This is what Wikipedia is saying they cannot do.
They have genes encoding some of this translation equipment, but they don't have enough of such genes to actually sustain translation independently.
Life can grow, respond to the environment, reproduce, and metabolize.
Viruses can do at least 3 of these things, but only by taking over the cellular equipment of their hosts. They cannot do these things independently.
Calling a virus a living thing would be like calling a flashdrive a computer. When you insert the flashdrive into a computer, it affects the behavior of the computer, and the flashdrive even has its own information, but the flashdrive still isn't a computer because it doesn't compute on its own.
Apparently the chlamydias and genus Rickettsia share some characteristics with viruses. They're no ordinary parasites, they're obligate intracellular parasites, entering inside the cells of their hosts as a requirement for survival (thus making it "obligatory").
The chlamydias have two forms, transforming into the reproductive reticulate body after being endocytosed by a host cell.
http://www.atsu.edu/faculty/chamberlain ... ickett.htm
They need to get their ATP from other cells, but they still have their own ribosomes (unlike mimivirus). That makes them heterotrophs, but not viruses. Furthermore, they have membranes, not mere envelopes.
But, considering that they aren't free living cells, you could argue that these parasites are more like organelles, much like the mitochondria and chloroplasts that contain their own genetic materia. If viruses are infectious genetic material, then maybe the chlamydias are infectious organelles.
I didn't read the entire article about these three "degenarte bacteria", but they could help the argument that Sumanth wants to make. By studying enough examples, perhaps Sumanth could make the argument that every characteristic lacked by viruses is also lacked by some sort of living microbe. Organelles have active membranes rather than envelopes, so we don't need to find a living microbe with a passive membrane. What else is there? The possession of ribosomes? Maybe some living microbes steal ribosomes rather than produce their own.
For those who don't know, some viruses have membrane-like structures called "envelopes".
I don't know what distinguishes a membrane from an envelope.
Who is online
Users browsing this forum: No registered users and 2 guests