Monday, September 23, 2002
The Sunday from Hell!
Let's just say that I had many papers to write, and a big test to study for, and I did it all in one day, and I didn't want to stay up late, so I was working all day with no breaks other than dining breaks. The evilness of this cannot be conceived.... unless, of course you are one of my classmates and you suffered through it with me.
That's all I'm going to say about the weekend. It's too painful to think about right now.
I can feel the college noose tightening around my neck. Can't you?
Today is painfully, oppressively humid. Not a fan of humidity. If you like humidity, you deserve to be punched in the schnozzola.
Wow, scary thing just happened! I was reaching around the computer to unplug my headphones (can't listen to my music when the devil-being is in the house, or he shrieks like a wounded harpy... but he has flown to tennis for now) and I knocked into the speaker. You see, the speaker is round. So when I knocked into it, it actually rolled. It almost rolled right off of the desk. But I grabbed it. And disaster was thus averted. But it gave me quite a scare.
They say that you learn best by teaching the material to someone else! Well, I sure need to learn. So I will proceed to teach you biology. You'll love it. I just know you will.
The nucleus! Enveloped in a double layer, with the intermediately fibrous nuclear lamina gracing the inner side! And you musn't forget the chromatin, or rather, the dense masses of DNA! Good times are had by all in the nucleolus, which is the nucleus of the nucleus!
We're going to skip the ribosomes, because they're just little protein factories, which are free or bound. Like slaves. Only ribosomes.
ENDOPLASMIC RETICULUM has a very tedious name. It has many cisternae (think cistern.. like a well, right?)... it is both rough (ooo, that rough reticulum! it's so good with the membranes... wow, that was dirty) and smooth (detoxifyingly smooooooth!).
The Golgi Apparatus... I don't know, when I first learned about this lovely little bundle of flattened sacs, it was called the Golgi Body. Apparently things have gotten more snooty and scientific. I still like to think of it in a bootilicious sense, though. It's got a cis and trans, and it's all bubbly and cool-looking. We call it a post office. You'd do well to refer to it in that sense, I think.
Lysosomes digest. Ooh my, but they are acidic! But basically, they digest.
Vacuoles are vacuous little bubbles of joy. They bring you food when you phagocytote. If you are a freshwater protist, they contract for you. If you are vegetative, they are big and central. With you couch potatoes, they are trashy, red and blue, poisonous, and sometimes they will elongate. But only when you're ready.
Mighty Mitochondria! Their cristae fold and make a matrix! But, alas, they are excluded from the exclusive endomembrane club. Those prissy little endomembrane bastards. But even without them, the Mighty Mitochondria toils on! It respirates, cellularly, of course. ATP is its very bestest friend. The energy that Mighty Mitochondria has is simply astounding!
The green and glorious chloroplast has 2 magnificent membranes filled with a squishilous liquid of the stromatic type. That is to say, stroma. It holds it's poker chips in a pile of thylakoids. Each poker chip pile is a grana. Granum? Singular, plural, quoiever. In any event, it is not a starchy amyloplast, and it is not a jaundiced chromoplast. It is a warmly verdant chloroplast!
Peroxisomes make hydrogen peroxide. Easy enough, I suppose. But since they make hydrogen peroxide, they must also clean up their filthy little mess. With enzymatic cleaner, of course. They use their enzymatic cleaner on many things, like alcohol in the liver... they take away the hydrogen of those unhealthful substances! Some of them are known by another name (ooo, so James Bond!)... glyoxysome. They turn those silly fatty acids into even sillier sugar... so plants can grow and grow and grow, even before they get their green photosynthesizin' act together! In seeds, I mean. Hooray for peroxisomes!
Now here is where it gets hairy. This stuff wasn't in middle school, or freshman year. This stuff is brand spanking new (well, maybe not spanking. we hope not) and it's teething. That's right. This information, my friends, is teething. And it's teething on my brain. And it hurts like the dickens, my friends, it hurts like the dickens.
The cytoskeleton. There are microtubules (think, little tubes) made of tubulin (yes, creative naming, scientists!) which hold up the cell, move the cell with marvelously motile motor molecules (AKA dyenins, powered by ATP), inhabit cilia and flagella (Liz does not like the word 'flagella'), and play the role of monorail for organelles, namely, those vacuous vacuoles.
There are microfilaments (think, little threads) of a globular (great word) protein known in certain circles as actin. These little buggers make the outer cytoplasmic layer a nice, soothing gel. They make ze contraction of ze muscles. The pseudopodia of an amœba would have no motion without a little microfilament action! They make blood cells that are white move here, there, and everywhere. Oh yes, and they are responsible for that fascinating phenomenon (not really) known fondly as cytoplasmic streaming.
There are intermediate filaments (think, threads bigger than microfilaments, but smaller than microtubules) that are not transients like the previous two! Oh no, the intermediate filament is no fair weather friend! He is with you through thin and thick! He holds you together like nothing else!
Only plants are priviledged enough to have a cell wall. I wish we had 'em! Anyways, this here wall is bricked up with only the finest polysaccharide cellulose microfibrils (remember, kiddies, cellulose is a plant schtick!). It has 3 parts: a primary cell wall (first in excellence, first in flexibility!), a middle lamella (mmm, lamella. sticky little pectins hold you cells togetha 4 eva), and a secondary cell wall (lying betwixt and between the primary cell wall and the dinky little plasma membrane, this fellow knows no rival in sheer strength! the more of him there is, the stronger he gets. duh).
Oh yes, and musn't forget the plasmodesmata (plaz-moe-dezz-mah-tah). These be wee little holes, laddie, and these be sitting in the midst of two big blarney cells. They lets the cytoplasm be continuous, they does.
And then, if you're a po' little animal, with no cell wall to call your own, we come to the extracellular matrix. It isn't 'extracellular' because it's extra cool... it's not. It's just 'extra' outside the cell. It's terribly complicated looking, with all sorts of shapes meshing together and I sure can't make heads nor tails of it. But it's all just GLYCOPROTEINS, which are proteins covalently bonded to carbohydrates, naturally.
And the extracellular matrix glycoproteins are! Ms. Collagen, a whopping 1/2 of all the protein in human beings! Ms. Collagen forms some very strong fibers outside of the cell, so let's all have a nice round of applause for Ms. Collagen!
Our next glycoprotein is Ms. Proteoglycan, who is the richest glycoprotein here today... rich in carbohydrates, of course! Ha ha ha! No, but seriously folks, she's sometimes 95% carbs, and Ms. Collagen is anchored by her, so let's give her a round of applause!
Next we have Ms. Fibronectin! Ms. Fibronectin doesn't do a blessed thing so far as we can see, other than bind cells to poor, beleaguered Ms. Integrin, so let's all give it up for Ms. Fibronectin but let's admit it, folks, she ain't winning a dern thing here today!
Last, but certainly not least, we have Ms. Integrin! She spans the whole cell membrane, folks, and that's impressive! On her cytoplasmic side she wears an elegant set of microfilaments connected to the cytoskeleton. Being a bunch of receptor proteins built into the plasma membrane, she sometimes has a hard time relating to freeer cell components. But she has overcome all that adversity to transmit messages between the interior and exterior of the cell! A real trooper! Let's all give a hand to the lovely Ms. Integrin!!
Now that the glycoprotein pageant is over, we can turn our rapidly waning attention to the Conjunction Junction, what's your function? Ha, no, I wish... actually, we're at the intercellular junctions. There are three kinds, and none of them make any sense, at least they don't with this picture I'm looking at here, but you can't see the picture. So maybe you won't be so confused. Well. Here be monsters:
The tight junctions. They're tight because they wear belts that are too small for them. No, they really make belts that go all around a cell, and boy o boy, do they ever fuse tight!
The desmosomes. They're like rivets, only the picture I have doesn't look anything like a rivet. Nothing at all. Well, they're the anchoring junctions (whatever that means), and they've got keratin to reinforce them, so I suppose that's good.
The gap junctions. Not a clothing store, these are actually the exact same thing as plasmodesmata, only in animal cells. So far as I can tell. If there's a difference, I haven't learned it yet.
You just learned my whole biology chapter!!
Yes, yes, you can thank me later.
Well, now I don't have to study for my test. I count that as studying.
Hope you all learned something new and important today!
Hee hee hee... MWAH HA HA HA HA HA HA HA HA!!! (<--- evil laugh, in case you couldn't tell)
And the winner of the glycoprotein pageant is.... exergonic! It has nothing to do with this chapter! But it's such a great word! Ecks-er-gone-ick. Incredible. I just love saying it. Exergonic! Exergonic!