a selection of unanswered questions
Ian.Musgrave at med.monash.edu.au
Mon Jun 3 19:32:29 EST 1996
Margaret Fowler <101722.35 at CompuServe.COM> writes:
>From: Margaret Fowler <101722.35 at CompuServe.COM>
>Subject: a selection of unanswered questions
>Date: 2 Jun 1996 23:05:01 GMT
>[NOTE: 1 June 1996: since posting last weekend, five replies were
>received, two (Ladasky of Stanford, Alex of ?Western Australia) not
>taking the questions seriously; one from Paul S Brookes of Cambridge,
>long but with elementary replies; one short reply from Van Frank of
>?MHAFC looking at a couple of questions; and a more considered reply
>from Cornelius Krasel in Wuerzburg.
You may be having trouble getting replies as most of your list of 48 questions
are already answered in the open literature. Few poeple will spend their time
trying to answer a grab bag of questions whose answers can be found with a
little effort on the part of the asker.
>UNANSWERED QUESTIONS IN BIOLOGY.
As I said, most of these have been answered. If you have problems with the
existing answers, you should address them. To avoid band width wastage. I will
briefly address a very few of them as a general illustration.
> The following questions have never been answered satisfactorily,
>several of them never at all:-
Then indicate which have been never answered and which have not been
satisfactorily annswered. To my knowledge, most have infact been answered
quite nicely indeed.
>Question 18: How can carriers assist the passage of ions, aminoacids,
> etc. across membrane, when the combination must be bigger than the
> substance carried?
Why on earth do you believe this to be a problem? There are several good
reviews on structure and function of carriers (most relating to proton
transporters). Look up a few issues of Trends in Biochemical Sciences, which
should be easily available. If you have problems with these theories, what
>Question 19: Why have few or no carriers been isolated?
Several proton transporters, five glucose transporters, two monoamine
transporters (at least). These are the ones I know of, and I deliberately
avoid the transporter literature. How many do you want?
>Question 26: Why is it assumed that the receptors for transmitters,
> hormones, messengers, antibodies, drugs and toxins are on the
> surface of the cell membrane?
It is not assumed, it has been experimentally demonstrated using several
different techniques (differental centrifugation, autoradiography, antibody
localization etc.) for some classes of receptor (heptahelicals, growth factor
receptors etc.) and also experimentally demonstrated that others are
intracellular (retinoid receptors, steroid receptors). Do you have specific
reasons why these techniques, especially when used in combination, should be
>Question 27: How valid is the use of agonists, antagonists and
> ligands to detect receptors, instead of the transmitters, hor-
> mones, antigens, drugs and toxins themselves?
Very. There is extensive literature validating these techniques, and any
number of basic "methods in.." books outlining the theories and results.
Receptors are usually "detected" using a number of ligands, (these ligands
usually include the appropriate native hormones/neurotransmitters as well), to
be certain of their identity. Many synthetic agonists/antagonists have been
specificallly synthesized to be specific for a particular receptor, so why do
you see a problem using them to "detect" these receptors in new tissues,gene
expression experiments etc.? Goodman and Gillman is a good place to start,
followed by T. Kennakins publictions (see especially reviews of physiology and
[rest of article snipped]
I could reply in detail to all of the above, but the information is
already available in the open literature (and time is too short). There are
many more examples in your list where the answers are already known, so it is
hard to take the entire list seriously. If you have specific problems with the
methods/techniques used to give the answers mentioned above, what are they?
Questioning our assumptions at regular intervals is healthy for science. But
posting a huge list of "no one has answered this" questions, when they have
indeed been answered is not going to start a useful debate.
Ian Musgrave Ph.D, Prince Henry's Institute of Medical Research
PO Box 5152, Clayton 3168, Australia.
Phone +61 3 550 4286 FAX +61 3 550 6125
Lab: Ian.Musgrave at med.monash.edu.au <http://www.mmcc.monash.edu.au/~ian-mu/>
Private: Reynella at werple.mira.net.au <http://werple.mira.net.au/~reynella/>
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