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Plant Sciences, Zoology & Evolution / Wohooo plants got their own section
« on: 04/10/2007 04:54:14 »
Yay plants, yay plants
This is cool!
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This is cool!
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General Science / Water on a hot skillet
« on: 17/09/2007 17:01:52 »
Hi All,
Why when you drop water in a hot skillet does it roll around and not just evaporate immediately?
I am assuming this has something to do with surface tension- but if y'all could provide a real explanation I would appreciate it!
If this has already been answered, please help me find the link, I couldn't find it in a quick search.
Thanks!
Why when you drop water in a hot skillet does it roll around and not just evaporate immediately?
I am assuming this has something to do with surface tension- but if y'all could provide a real explanation I would appreciate it!
If this has already been answered, please help me find the link, I couldn't find it in a quick search.
Thanks!
3
Cells, Microbes & Viruses / Where Does DNA Come From
« on: 15/04/2007 04:42:53 »
Hi Paul, George, and Seany,
I thought your "what am I" conversation was very interesting. I wanted to join in, but by the time I had time- y'all had moved on in the conversation- So I'm starting my own:
So where did DNA come from. . .
The idea is that originally it was an RNA world. RNA and DNA are very similar- there is only an extra oxygen on RNA sugar that is missing from DNA (and one of the bases is different). See the extra 'O' in the picture below.
[ Invalid Attachment ]
But this extra oxygen makes a huge difference- it makes RNA more reactive than DNA. The good thing about being more reactive is that it means that RNA can actually act as an enzyme- in other words it can actually do stuff- it can chop up other RNAs, make more RNAs, even make proteins which are very good enzymes. As George pointed out, DNA can't do this (as far as I know). For some reason (and this is a really interesting question- but probably deserves a whole different post) some RNA molecules started making more RNA molecules- and those that were good at it kept going and those that weren't, well you don't see them around anymore.
Then some RNA molecules started using other molecules in the environment to help them make more copies of themselves- eventually making proteins and cells to protect themselves from getting destroyed and to keep the things they made to themselves. So being reactive allowed RNA molecules to start increasing in number and complexity. However, being more reactive has its downsides- it also means that RNA is more sensitive to getting destroyed. Therefore, in comes DNA- DNA is much more stable. So whenever long term storage is needed DNA is used. RNA is still used to translate the DNA into proteins and as some enzymes to do many functions in the cell. But when keeping the data intact is really important, DNA is used.
There are still some viruses that only use RNA to store there information- they are subject to high rates of mutation- but then, this has some advantages for a virus.
OK, enough fun. . back to work.
Colleen
I thought your "what am I" conversation was very interesting. I wanted to join in, but by the time I had time- y'all had moved on in the conversation- So I'm starting my own:
So where did DNA come from. . .
The idea is that originally it was an RNA world. RNA and DNA are very similar- there is only an extra oxygen on RNA sugar that is missing from DNA (and one of the bases is different). See the extra 'O' in the picture below.
[ Invalid Attachment ]
But this extra oxygen makes a huge difference- it makes RNA more reactive than DNA. The good thing about being more reactive is that it means that RNA can actually act as an enzyme- in other words it can actually do stuff- it can chop up other RNAs, make more RNAs, even make proteins which are very good enzymes. As George pointed out, DNA can't do this (as far as I know). For some reason (and this is a really interesting question- but probably deserves a whole different post) some RNA molecules started making more RNA molecules- and those that were good at it kept going and those that weren't, well you don't see them around anymore.
Then some RNA molecules started using other molecules in the environment to help them make more copies of themselves- eventually making proteins and cells to protect themselves from getting destroyed and to keep the things they made to themselves. So being reactive allowed RNA molecules to start increasing in number and complexity. However, being more reactive has its downsides- it also means that RNA is more sensitive to getting destroyed. Therefore, in comes DNA- DNA is much more stable. So whenever long term storage is needed DNA is used. RNA is still used to translate the DNA into proteins and as some enzymes to do many functions in the cell. But when keeping the data intact is really important, DNA is used.
There are still some viruses that only use RNA to store there information- they are subject to high rates of mutation- but then, this has some advantages for a virus.
OK, enough fun. . back to work.
Colleen
4
Just Chat! / Where are we going on Our trip!
« on: 22/03/2007 23:40:14 »As a firm believer in empirical study I think this calls for a Naked Scientist sponsored field trip to Greenlandhow may of "us" will go? and will we get to see santa?
Paul, why don't you ask a good question that needs a field trip to someplace warm?
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Physics, Astronomy & Cosmology / What is sonoluminescence and how might it be used?
« on: 07/02/2007 23:45:13 »
Hi,
I see there have already been some posts on sonoluminescence, and an explanation of what it is, but I didn't see an explanation about why it occurs. Is there a consensus about what causes this? Are there any practical applications yet? Or is it just still a cool phenomenon?
Thanks, Colleen
I see there have already been some posts on sonoluminescence, and an explanation of what it is, but I didn't see an explanation about why it occurs. Is there a consensus about what causes this? Are there any practical applications yet? Or is it just still a cool phenomenon?
Thanks, Colleen
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Guest Book / Helloooo Wonderful Site
« on: 21/12/2006 14:41:31 »
Hi Y'all,
I love this site, I've been checking it out as a guest and finally decided to join (even before the begging started). I look forward to the podcasts coming out every week and I am going to miss them over the holidays. Anyway, thanks for keeping a well run interesting site, and I hope you don't mind if I pop in an opinion or thought once in awhile.
c-ya
Colleeeeen
I love this site, I've been checking it out as a guest and finally decided to join (even before the begging started). I look forward to the podcasts coming out every week and I am going to miss them over the holidays. Anyway, thanks for keeping a well run interesting site, and I hope you don't mind if I pop in an opinion or thought once in awhile.
c-ya
Colleeeeen
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