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| Author |
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| 25 new of 98 responses total. |
rcurl
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response 40 of 98:
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Nov 6 06:33 UTC 1999 |
..and #37 is 1-propanol (old name: normal or n-propanol).
There is no specific *charge* difference between the + and - "ends" of
a water molecule. However the water molecule has a dipole moment of
1.87E-18 e.s.u. (you asked...).
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oddie
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response 41 of 98:
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Nov 8 04:36 UTC 1999 |
You're right, I did :) Textbook descriptions usually say that water has
a slight charge on either end, without giving any quantitative description
of the actual magnitude of the difference, and I had assumed that it was
possible to describe the different distributions of charge in the units
of charge itself. I now know better...
You know, I might still be wrong about the isopropyl structure. I think it
might actually be the case that the middle carbon of the propyl chain
has a -C-OH (methanol) group bonded to it; the reasoning behind the name
would be that either side of the symmetrical molecule "looks" like a
propanol chain. I'm not sure how to name such a compound under IUPAC
rules, however; maybe 2-methanol-propane??
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-C-C-C-
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-C-
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OH
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rcurl
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response 42 of 98:
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Nov 8 06:24 UTC 1999 |
It is 2-methyl-1-propanol. It is, of course, a *butanol*, but there are so
many isomers of butanol that common names are available for only a few.
It could also be called 1,1-dimethyl ethanol, but the naming convention
calls for the largest simply identifiable radical to be the basis of the
name.
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oddie
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response 43 of 98:
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Nov 9 04:53 UTC 1999 |
Thankyou Rane, Russ, and Andrew (& anyone else whose name I've forgotten)
for your answers. Now I will have to think of some more questions. (:
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srw
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response 44 of 98:
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Nov 28 19:36 UTC 1999 |
Hmm. I would have guessed that there were only 4 isomers of butanol.
I was thinking of two different places for the OH on a straight butane,
and two different places for an OH on an isobutane. That doesn't seem
like so many to have common names, but maybe it is.
The conventional names (I suspect) are:
1-butanol
2-butanol
2-methyl-1-propanol (our friend), and
2-methyl-2-propanol
As far as I can tell, none of these 4 have stereoisomers.
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rcurl
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response 45 of 98:
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Nov 28 22:27 UTC 1999 |
Four is "too many" (you know, one, two, three, infinity...). Three have
common names; normal (n-), secondary (sec-) and tertiary (t-) butyl
alcohols. "Our friend" has no common name. 2-butanol has a stereoisomer
since the 2- carbon has four different groups attached. They are
d-2-methanol, and l-2-methanol (and of course the racemic mixture).
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srw
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response 46 of 98:
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Nov 29 20:54 UTC 1999 |
Ok - I'll accept that four us too many. It sounded like more somehow.
Ah - yes I missed the 2-butanol stereoisomer. thx
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orinoco
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response 47 of 98:
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Nov 30 00:54 UTC 1999 |
If dehydration is a Bad Thing, then why does the body excrete more water, the
more it takes in? Is there any survival value to this, or is it just a side
effect of how the relevant systems work, or what?
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i
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response 48 of 98:
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Nov 30 01:12 UTC 1999 |
Excess water is also a Bad Thing - the body's got to get rid of it.
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orinoco
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response 49 of 98:
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Nov 30 02:29 UTC 1999 |
Ah, okay.
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russ
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response 50 of 98:
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Nov 30 05:48 UTC 1999 |
(Lots of things in the body, like nerves and muscles, depend on the
ion concentrations of the blood and other fluids being within certain
limits. Too much water thins them out, and stuff starts malfunctioning.
This is bad, because you don't live too long if your nerves quit on you.)
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rcurl
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response 51 of 98:
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Nov 30 06:52 UTC 1999 |
It is nice, though, that the body goes to the trouble of absorbing extra
water and excreting it through a more convenient orifice, rather than just
not absorbing it.
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orinoco
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response 52 of 98:
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Nov 30 18:59 UTC 1999 |
Nice why?
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rcurl
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response 53 of 98:
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Nov 30 19:53 UTC 1999 |
Think.
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orinoco
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response 54 of 98:
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Nov 30 22:51 UTC 1999 |
I don't, remember? It's in my handle. :)
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russ
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response 55 of 98:
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Dec 1 04:17 UTC 1999 |
Maybe if you'd go to the trouble of absorbing and conveniently excreting
your text, you wouldn't have this keyboard diarrhea. ;-)
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keesan
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response 56 of 98:
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Dec 6 15:51 UTC 1999 |
The human digestive system is open at both ends (mouth and anus). If water
went in one end and were not absorbed where would it come out? Orinoco, I
think you would enjoy a first-year biology class even if not required.
(I am afraid I don't get the joke in 55.)
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orinoco
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response 57 of 98:
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Dec 6 16:16 UTC 1999 |
Russ' remark made the situation clear enough, but thanks anyway keesan...
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russ
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response 58 of 98:
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Dec 7 03:32 UTC 1999 |
It was an attempt at humor on response 51.
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oddie
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response 59 of 98:
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Jan 28 04:53 UTC 2000 |
We are doing genetics in biology at the moment, and so I was wondering:
broadly speaking, how is eye color controlled in humans? Is there more
than one gene affecting it, more than one allele, or what?
We are doing sex-linked genes at the moment. Genetics is fascinating.
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keesan
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response 60 of 98:
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Feb 2 02:20 UTC 2000 |
Two genes for brown eyes make brown eyes. Two genes for blue eyes make blue
eyes. One of each gives you hazel/green/light brown eyes. There are probably
several alleles of the brown-eye gene for different amounts of pigment. Don't
know if more than one gene is involved. But two blue eyed parents will not
produce a brown eyed child, though two brown-eyes can produce blue, as the
blue acts recessive.
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oddie
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response 61 of 98:
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Feb 2 04:55 UTC 2000 |
I'm not sure I understand--two "genes" for brown eyes make brown eyes, or
two alleles? In biology class we did one problem where the premise was
that there was one gene for eye color and the brown allele was dominant
over blue, but Mr. Stanley told me that this was a simplified view.
THis hypothesis explains why children of brown-eyed parents can be blue-eyed
(if both parents are heterozygous then both can pass down the recessive
blue allele) but says nothing about other colors.
If there is more than one version of the brown-eyed allele, perhaps there
is one "strong" version, fully dominant over blue-eyes, and a "weak" version
that is codominant with blue eyes?
I could look it up in the big blue tome at school entitled "Mendelian
Inheritance in Man" but I suspect any references there would be a bit too
technical for me...
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tpryan
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response 62 of 98:
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Feb 3 01:47 UTC 2000 |
My two hazel eyed parents had eight hazel eyed kids.
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russ
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response 63 of 98:
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Feb 3 04:44 UTC 2000 |
My two blue-eyed parents had one hazel-eyed kid, and two blue-eyed.
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keesan
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response 64 of 98:
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Feb 4 13:33 UTC 2000 |
I did a search on 'eye color' with AltaVista. From the first source:
Reliable Answers on Eye Color by the MIT Guy 1
By JJ Brannon
[1]jjbrannon@aol.com
_________________________________________________________________
I was a student of Salvador Luria [Nobel Laureate for Genetics] at MIT.
Two brown-eyed parents can easily have a blue eyed child.
Two completely blue-eyed parents CANNOT have a fully brown-eyed child with
normal eye development except in certain extremely rare circumstances.
The gene for brown/blue eyes is EYCL3 found on Chromosome 15.
The gene for green/blue eyes is EYCL1 found on Chromosome 19.
Brown is the result of melanin deposits in the iris.
Green is the result of [this is debated] lipochrome deposits in the iris.
Blue-grey [and in some albinism, pink] is due to a lack of pigment in the iris
.
The underlayer, called the stroma, reflects light through its cells like
a mirror's silver back. How the pigment is distributed over the iris involves
other genes which produce flecks, rays, rings, partial diffusion or
full diffusion. This inheritance is very complicated and the genes have not
been well identified.
Here are some reliable sources:
http://www.ncbi.nlm.nih.gov/htbin-post/Omim/dispmim?227220
http://www.ncbi.nlm.nih.gov/htbin-post/Omim/dispmim?227240
http://www.gdb.org/gdb-bin/genera/genera/hgd/ObjectName/2662023?!sub=0
Francis Galton -- Davenport & Davenport -- Bryn & Winge -- Lenz -- Hughs
as discussed in
Human Genetics, Chapter 5, by Reginald Ruggles Gate [1952]
Heredity & Your Life, pp. 286-312, Boyd [1950]
_________________________________________________________________
References
1. mailto:jjbrannon@aol.com
2. http://sln2.fi.edu/tfi/units/life/forums/anatomy/anatomy.html
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