Cytoskeleton

cy•to•ske•le•ton (noun)
the protein tubules and filaments present in cells that serves many different function including structural support, movement, growth, etc.
Origin: Greek via English [kyto- (Greek) = container -> cyto (Eng) = of the cell, skeletos (Greek) = to dry -> skeleton (Eng) = various structures forming a rigid framework]

~~~~~~~~~~

The Cytoskeleton is to the cell as a skeleton is to animals, just like Organelles are to the cell as organs are to animals. The cytoskeleton in eukaryotic cells (do you remember what a eukaryotic cell is? what features define an organism as being eukaryotic? what is the counterpart to eukayotes? what features define those organisms as a group? if you don't know, stay tuned for the next post!) is primarily composed of three things: Microtubules (MTs), Actin Filaments (or simply, actin), and Intermediate Filaments (IFs).

Each of these components is a polymer of a simple protein monomer/subunit. In essence, a monomer is like a piece of Lego and the polymer (the filaments and tubules) are made by putingt many of them together in a very specific pattern. Each of the three components has its own monomer: MT are made from subunits called Tubulin, which are proteins that look like two blobs stuck together, kind of like a two-part snowman that stick head-to-tail to form protofilaments, and then protofilaments are arranged in a ring to form hollow tubules; actin is made of subunits called G-actin, which are proteins that look like globose blobs that attach to each other to form double helaces; IFs are made of long, skinny, rope-like proteins that twist together to make filaments.

Like how a skeleton is important for people to be able to live, so is the cytoskeleton important for cells to live. Cytoskeleton components are involved in so many different important cell functions:

Actin:
-provides support for the cell membrane so that it doesn't break easily
-pinches the cell membrane together during cell division so that the two new cells can separate
-bundles together to form fibres that resist stress
-are very flexible and are highly involved in phagocytosis
-are the filaments that move and are responsible for muscle contractions

Microtubules:
-are like railway tracks that direct the movement of organelles
-help position organelles correctly in the cell
-are one of the main components of flagella and cillia
-are the fibres that separate chromosomes during cell division

Intermidate Filaments:
-provide structural integrity to the cell
-is very elastic and the strongest type of filament
-help maintain the shape of the nucleus and the cell
-helps align cells in the tissue of multicellular organisms

~~~~~~~~~~

Can you tell that I'm cheating by using the blog to help me study for my Cell Biology exam tomorrow? =P Hooray for killing two pigeons with one grain of rice! I mean... what?

I had two exams yesturday: NVP Bio and Multivariable Calculus >.< The Bio one went okay; there were several questions that totally threw me for a loop, but I think overall I did well. I was a bit disappointed because remember how last week I had to write the lab exam for this bio class? I got my mark back, and I got 75%; it's not bad, but I was expecting a better mark. A lot of the word answer questions were looking for a lot more than I thought; most of them I answered with two or three points, and it ended up being out of something like ten marks, which I wasn't expecting. I totally would have written way more and gotten more marks if I had known they were looking for so much; instead of concentrating on those questions, I was concentrating on the questions where I had to identify the organism under the microscope in front of me. I was hoping for a really really high mark in the class so that it could boost my average. I dunno, we'll see how it turns out.

Being in the exam halls at UBC makes me feel like an anachronism belonging to the distant past; to think that my parents wrote their exams in the exact same hall exudes a sense of timelessness, I suppose. Your last post made me ponder about why I like being so abnormal, and why I am so adamant to be as abnormal as possible: am I being different for the sake of being different, or am I different because what I want to be just happens to be the opposite of the norm? I think I came to the conclusion that for the most part, I'm different because who and what I want to be just happens to be different from the norm. Certainly, being crazy and wacky, which is totally considered abnormal, is so much more FUN than acting/being what others consider "normal."

Also, I was slightly confused by one of your points: you said that you feel like a misfit at this time of year, but also that you feel like an anachronism this time of year too. Going by your given definition, wouldn't an anachronism in today's holiday season be one of those people among the crowds lining up at stores in the malls? Maybe I'm misinterpreting what you wrote.

TEEHEE lol no offense, but what happened with the dorm christmas decor seems rather stereotypical of you all, not to be sexist or anything =P Sounds like you'll be enjoying the exam season with Christmas spirit for the last few weeks at Trinity this year. LOL and that quote was quite fantastically graphic XD

Anyways, I should get back to my books. Such is the life of a Science student... I feel like a slave to my textbooks, but it's almost over! AND THEN THE INTENSE POKEMON AND SNOW FUN SHALL BEGIN! SO EXCITED!

Good luck with all of your exams!
Chat soon
~Tim~