What’s the best Halloween costume you’ve ever made? Or seen?
Discuss in the comments!
Tools for the Toolbox: Proteins!
Your choice of chicken, beef, or tofu!
No, the physiological meaning of “proteins”, not the pop-culture meaning.
Oh. Are they at least nifty?
Of course! Would I talk about them if they weren’t?
Maybe. If you wanted to talk about something else that was nifty.
Fair enough.
But they’re nifty themselves.
Well, yeah.
So, what’s nifty about them?
Besides the fact that they’re like little legos and snap-beads and erector sets and other types of kids’ building toys that thoroughly delighted me when I was little?
Um…doesn’t have to be BESIDES that…
Well, okay. I’ll start there.
Proteins are cool because they’re basically the things that cells use to DO things and MAKE things.
Need a tunnel through your cell membrane for charged particles to swim through? Use a protein!
Need an enzyme to catalyze a step in your biochemical process? Use a protein!
Need something to carry oxygen from one part of your body to another? Use a protein!
Need a scaffolding in your cell body to hold its structure and provide a transport railway system from the nucleus to the cell membrane? Use a protein!
Need a doomsday device to strike fear and terror into the hearts of the good, hardworking peasants on the greater continent of Anteuri 2?
I’ll use a protein!
Um……okay, maybe you can’t use a protein for that.
You know, you get carried away WAY too easily.
But it’s so fun to carry you with me!
Wow, there are SO many things I could say after that comment.
We’re totally getting off track.
And it’s totally your fault.
Which…if you could forgive the meta-comment…would be the case even if it was YOUR fault….
Would you just get back to the proteins?
Right.
So.
Let’s make a protein!
We’re going to start with the basic building block of a protein, the amino acid.
Oh, look! A table that shows the twenty standard amino acids that our bodies tend to use to make proteins!
How convenient!
Wow, I wonder how THAT got there?
If you look closely at the convenient table (click to embiggen), you can see that even though they all look different at the top, each amino acid basically has the same structure at the bottom. Namely, they have an amino group ( H2N- ) and an acid group ( -COOH ).
Oh! So THAT’S why they’re called amino acids!
Yup!
By the way…what’s the deal with the whole “essential amino acids” thing? I hear that phrase all the time.
There are some amino acids that our bodies can synthesize by themselves. But there are other amino acids that we just can’t…particularly: leucine, isoleucine, lysine, valine, methionine, threonine, phenylalanine, and tryptophan. So, it’s ESSENTIAL that we get these amino acids from our diet, because we can’t make them ourselves. Get it? Get it? ESSENTIAL amino acids.
Okay, got it! So, they’re building blocks.
Yeah! So, amino acids are like those attachable plastic beads I used to play with as a kid. Each type of bead was a different shape and color, but they all had identical snap-together connections that you could use to connect any bead with any other bead, and make any kind of pattern you wanted to!
She's making a DNA polymerase.
Likewise, you can string the amino acids together to make any pattern of amino acids that you want to make your protein! This is called a primary structure.
And now the true fun begins!
I’m using the bead analogy because it’s convenient. But if you look up at the table again, you’ll see that even though they attach together and string along like beads, they’re really more similar to puzzle pieces!
Or lego rings? Kinda?
What I mean to say is that each “bead” on the sequence has a puzzle piece (a “side chain”) attached to it. And the puzzle pieces fit together in different ways, because they all have different properties. For example, the positively-charged side chains will repel each other, but attract the negatively-charged side chains.
As a matter of fact, the amino acids would make a great soap opera:
Histidine, Lysine, and Arginine are sisters, all from the well-to-do Positively-Charged family of the Amino Acid estate. And they all hate each other. As a matter of fact, they’re so alike that they repel each other. But what happens when the Acid Brothers, Glutamic and Aspartic come to town? They’re both negatively-charged bad-boys…and they’re oh-so-attractive!
Tune in next week, as Lysine says: “Oh, Aspartic! I find you so attractive! But you’re attracted to Arginine! She’s so repellent!”
I’d totally watch that.
I’ll get the popcorn.
You’re supposed to be saying something that makes that….ahem…..”writing”…..up there relevant to the subject matter.
Okay, fine.
So, some amino acid side-chains are positively-charged, and some are negatively-charged, and some are neutral, and some are repelled by water. So when you let go of the ends of the string of amino acids you made….
Hilarity ensues!
Exactly! If by “hilarity” you mean “folding into higher-order structures”.
That’s exactly what I meant by “hilarity”!
So there are some very predictable patterns of hilarity that ensue. For example, proteins love to fold into a structure called an alpha helix:
Shamelessly borrowed from http://www.hcc.mnscu.edu/chem/V.27/page_id_27148.html
Or a beta-sheet:
Shamelessly borrowed from the same folks: http://www.hcc.mnscu.edu/chem/V.27/page_id_27848.html
These are called secondary structures.
After the secondary structures are formed, the rest of the hilarity repels and attracts and pushes and pulls itself into a beautiful, complex wire-sculpture-like tertiary structure.
Like this:
Or this:
Or this:
And then, sometimes multiple proteins in their tertiary structures join together in a quaternary structure, as you can see with the four subunits of hemoglobin.
Each individual protein is a different color in this picture; you can see how they come together in their quaternary structure!
Cool, huh?
And even cooler are all the things you can do with…..
Awoooga! Awooooooooga! LONG POST ALERT!!! People in the Internet Age have short attention spans! And you’re on vacation!
Oooh, thanks for keeping an eye on that for me.
You bet!
Well, folks, I’m going to skedaddle!
Tune in next time, when Tryptophan says: “AAAAAAAAA!!! WATER!!!! GETITOFFGETITOFFGETITOFFGETITOFF!!!!!!”
and we talk about what we can do with the awesome little proteins that we made!
(And how we can use them in writing.)
(That’s what you’re really here for, right? I thought so. 😀 )
Table:
http://www.neb.com/nebecomm/tech_reference/general_data/amino_acid_structures.asp
Pictures:
http://www.growingyourbaby.com/2009/12/09/recall-edushape-snap-beads-due-to-choking-hazard/
http://www.rxlist.com/forteo-drug.htm
http://www.crystalkiss.com/interlocking-lego-rings-for-people-in-love/
http://www.org.chemie.tu-muenchen.de/people/mh/Kdp/kdp.html
http://www.di.uq.edu.au/sparqproteins
http://chemistry.umeche.maine.edu/MAT500/Proteins8.html
http://www.chemistry.wustl.edu/~courses/genchem/Tutorials/Hemoglobin/151_T3_hemoglobin.htm
The contents of this site, such as text, graphics, images, and other material contained on the Site (“Content”) are for informational purposes only. The Content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this Site!
If you think you may have a medical emergency, call your doctor or 911 immediately. This blog does not recommend or endorse any specific tests, physicians, products, procedures, opinions, or other information that may be mentioned on the Site. Reliance on any information provided by this blog, or other visitors to the Site is solely at your own risk.
The Site may contain health- or medical-related materials that are sexually explicit. If you find these materials offensive, you may not want to use our Site. The Site and the Content are provided on an “as is” basis.
If you use this as if it were real medical information, I’ll denature your proteins. And you won’t even notice until the next post, when I talk about what “denaturing” means!
JourneyQuest: Web Series Plug!
An old college buddy of mine is involved with the rather delightful fan-supported web series, JourneyQuest.
Neat BBC-esque production values, occasionally laugh-out-loud cleverness in the writing, unabashed goofiness, and a healthy dose of self-awareness make this Just Fun Watchin’.
I love the characters, the fresh new takes on older tropes, and the overall feel to the thing.
I’m not quite convinced by the talking sword yet, but I’m willing to give it a shot.
Anyway.
Here are the first couple of episodes. Catch the rest at http://www.journey-quest.com/ !
Enjoy!
A Different Flavor of Bliss
Sitting on my parents’ porch surrounded by the darkening autumn woods at sunset, writing my novel while the aroma of my dad’s amazing chicken chili begins to waft from the kitchen. Chirping crickets and softly-hooting owls occasionally interrupt the languorous rush of the water in the creek down the hill. I can hear rustling in the leaves by the creek; I’ll bet it’s a raccoon.
I love visiting my parents.
(It doesn’t hurt that they’re also incredibly cool people.)
Hmm.
I was going to talk about nerves.
But….um…..I realized that I’d end up talking about rather complex concepts without providing any kind of framework to think about them.
I think I might need to back up.
I know, I’m such a tease.
But how can I talk about the propogation of action potentials when I haven’t even talked about the properties of cell membranes? Or ions?
I mean, I’m sure a lot of you know this stuff already. But I’m trying to go super-layman on the blog, because not everyone has studied this stuff.
So. Um. Bear with me? ::Hopeful grin?::
(PS: SuperLayman – Lamest. Superhero. Ever.)
Surprise!
So, I went to work this morning and was met with a lovely tableaux of the very surprised faces of my team…
…and my replacement on the service.
Apparently, my vacation starts TODAY, not tomorrow!
Surprise!
I’m totally napping in my hammock.
And writing. Writing too. I think I’ll hit the novel today.
Surprise vacation!
Wooooooooooooooooo!
Tools for the Toolbox: _. . ._. …_ . …
In honor of the fact that I’m rotating through Neurology at the moment, I’m proud to present…
NERVES!
(In case you don’t read Morse Code and were too lazy to google it, that’s what the title says.)
So, nerves are super-cool.
Here’s a picture of one, so you can join me in basking in the coolness of nerves.
Are you basking?
What’d I tell you? Coolness personified.
Well, maybe not personified….but if you squint closely, you may find yourself glancing at your neighbor and having a shift in perception, suddenly seeing his shape described only by a network of white, filamentous strands, as if he were a sculpture of spiderwebs….
Only me?
Darn.
Well, that’s okay. I also subconsciously judge people based on how easily I could start an IV in the veins on their hands.
(The study of medicine engenders its own special flavors of crazy.)
Anyhoo. NERVES!
A nerve cell is called a neuron. That’s the cell in whose coolness we were basking, up there a minute ago.
The job of a neuron is to pass information along, in the form of an electrical signal. (The way this happens is super-cool, and warrants its own post, so stay tuned. For right now, we’ll just talk about how they’re arranged.)
There are three parts to any neuron.
The dendrites (from “dendron”, which means “tree”) are the tree-branch-like projections off of the central cell body, also known as the soma or perikaryon. The dendrites collect impulses from surrounding neurons and send them to the perikaryon. There are usually a lot of dendrites on a neuron, making it easier to collect a LOT of information.
(Dendrites are probably the coolest things in the human body, because they like to rearrange themselves like crazy, making a dynamic structure that allows us to learn and remember things, and adapt to changes and all kinds of other important things like that.)
So, a neuron receives signals through its dendrites. But what if it wants to say something to the other nerves in the area? That’s where the third part of a neuron comes in, the axon.
Axons are incredibly cool structures, too! There’s a conical process on one end of a perikaryon called the axon hillock, and that’s the staging platform that shoots off the axon, a long, cylindrical filament that keeps its diameter for practically its entire length (whereas the dendrites tend to taper off). Axons are responsible for carrying information away from the perikaryon, toward whatever it’s supposed to connect with and talk to. Wherever it is.
(Think about how far away the tip of your toe is away from the end of your spinal cord [it’s a little above the level of your iliac crests, if you remember from this post. ] A nerve axon has to run that entire distance to carry its signals! They’re LONG, man!)
Okay, a little more terminology, then I’m calling this post a wrap and going to bed. And then we’ll get to the REALLY incredibly cool stuff in the next couple of posts.
The connection where nerves can talk to each other (or to muscles or gland cells or whatever) is called a synapse. Axons can form synapses with cell bodies, dendrites, or even other axons. For clarity purposes when describing nerve connections, a neuron sending a signal toward the synapse is called “presynaptic”, and a neuron that receives the signal from the synapse is called “postsynaptic”.
Makes sense, right?
Synapses are oases of awesome in a desert where the sand is made of unabashed coolness. They might get their own post. Or a couple. We’ll see.
Anyhoo. NERVES!
Axons are covered with a nifty stretch of jointed insulation, called a myelin sheath. More about that, too. Later.
I know you can’t wait. I hardly can either.
But I’m pushing bedtime as it is.
Man, I’m a geezer already.
But that’s okay. At least you can read this at three in the morning, if you want.
Because your nerves make it possible.
NERVES!!!
Pictures:
Resources:
Junqueira, Luis Carlos; Carneiro, Jose. Basic Histology: text and atlas. 11th edition. McGraw-Hill, 2005.
The contents of this site, such as text, graphics, images, and other material contained on the Site (“Content”) are for informational purposes only. The Content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this Site!
If you think you may have a medical emergency, call your doctor or 911 immediately. This blog does not recommend or endorse any specific tests, physicians, products, procedures, opinions, or other information that may be mentioned on the Site. Reliance on any information provided by this blog, or other visitors to the Site is solely at your own risk.
The Site may contain health- or medical-related materials that are sexually explicit. If you find these materials offensive, you may not want to use our Site. The Site and the Content are provided on an “as is” basis.
If you use this as if it were real medical information, I’ll bask in the cool awesomeness all by myself. Didja hear me? ALL BY MYSELF! (So there.)
Cliffhanger
(::overwhelmingly dramatic trailer-announcer voice::)
For one single, sacred day during the 2010 section of Intern Year, the forces of Light and Darkness align.
Lost in a strange land, immersed in a two-week stint of Foreign Service, Dr. Grasshopper experiences an overwhelming wave of culture shock!
(::Cut to: Dr. Grasshopper’s slack-jawed, disbelieving face::)
“Neurologists…..DON’T work……..on Columbus Day?!”
(::Cut back to: …..well…..whatever we were looking at during the first part. Perhaps a picture of a platypus?::)
Can Dr. Grasshopper navigate the Forces of Evil…
(::flash photos: of piles of laundry, stacks of medical textbooks, mountains of dirty dishes, less impressive amounts of almost-due bills, and an eeeeeeeeeeevil hammock (Of! Evil!) ::)
…..and Actually Manage To Write Something for the blogosphere tomorrow?
(::Horrified scream::)
Tune in next time, dear denizens of the Interwebzes, for…….
DR. GRASSHOPPER Vs. A SECOND DAY OFF!!!!
(::Another horrified scream::)
Coming soon, to an Imaginary Friends Blog Near You!
Perhaps a picture of TWO platypi?
(Picture from: http://swenglishrantings.com/Animals/ )
How To Kill Your Imaginary Friends 