Thread: How do we know....

Biochemistry is really cool but, I just can't figure out how we know this stuff.

For example: Muscle physiology. How do we know the structures of the actin and miosin and how do we know about the calcium and entering and binding etc. It's not like you can just look at a muscle and see all of this. Is it jsut really good guesses or what?

This may be more of a biology question.

Few possibilities:

Scans
Surgery
Corpses (they used to use them in more ancient times for medical study)
General observation


I'm sure there are a few more, but those are off the top of my head.

A lot studies on the function of proteins (and hence the molecular physiology) are done by knock out studies. Seeing what abnormalities the mice has if the protein is no longer present.

To fine tune the function of proteins they also use mutated proteins (transgene mice expressing the mutated protein. They see at the abnormalities in the mice when for example the Ca binding part of the protein is mutated, hence it can not bind Ca anymore.

Also the use of decoy protein is popular, since some knock outs die before birth or quickly after. In this case another protein is injected into the mice which block the whole or certain functions of the protein.

I didn't think about animal studies but still isn't that just hypothesizing. I mean it's not like they are actually watching the reactions take place.

There are visualisation techniques of course. By fluorescence microscopy you can visualize actin and myosin bundles. Also by electron microscopy one can look at cell organelles. To look at how proteins interact and how their structure are; they are crystallised and scanned by X-Ray.
But indeed science contains many hypotheses, which are challenged and proved or not.

And why is seeing believing...

Originally Posted by Him

There are visualisation techniques of course. By fluorescence microscopy you can visualize actin and myosin bundles. Also by electron microscopy one can look at cell organelles. To look at how proteins interact and how their structure are; they are crystallised and scanned by X-Ray.
But indeed science contains many hypotheses, which are challenged and proved or not.

And why is seeing believing...

It isn't. It's just so much of what we are taught is visual and I am not taught how we know such things. I think that would be very interesting to add to classes.

I agree, although learning is a stepwise process. In general people do not have that touch with science which makes it easy to learn things. Most people have trouble enough understanding how muscle work at molecular level; without talking how they figured it out.
You could argument the more you know of how they did found it out will make it easier to understand; but scientific methodology has grown far to complex to use it as a didactic approach.
But still I agree, especially when you want to educate researchers, even then the focus is too less on how we know all this stuff.

Another thing that bothers me about modern society. People are pressured into getting jobs to support themselves that they go into feilds they don't care at all about and just want the basics.

What's with all the name changing now days also. Instead of Bowman's Capsuel it is Glomerular Capsule. It takes away from the history even more. Any psychologist knows that the more meaningful and abstract something is the easier it is for us to remember so why are we changing things. Now I have to remember both names which just makes it stupid. When you say Bowman's Capsule not only does the term now have an identity making it abstract and memerable but it also reminds you that it is in fact us (people) that figured this stuff out (since it was named after the discoverer). Glomerular Capule is just a bland name refering to the a ball of thread (latin) which is represented by the capilaries, not to mention it is hard to say. I guess I just like thing the old fashioned way.

They are just models, but in many instances the components of the reactions can be isolated and seen to function in vitro.

The proton pump was shown in operation in this manner:

http://www.thescienceforum.com/ATP-Synthase-3455t.php

Originally Posted by invert_nexus

hey are just models, but in many instances the components of the reactions can be isolated and seen to function in vitro.

The proton pump was shown in operation in this manner:

http://www.thescienceforum.com/ATP-Synthase-3455t.php

Coolness!