by Angela Armstrong
Salutations, o wayward traveller. My name is Rhistorl. I am a coelacanth of the order Sarcopterygians. I have come into an l'll bout of magic that has shrunk me down to invisibility. I have encountered a single celled organism. Hey, I might as well explore...
The turnstiles of the cell
The cell membrane disapeared at the edges of the clouds of tiny water molecules. I didn't know why they were that big, big enough to see and feel. The Cell Membrane was composed of phospholipids and large specialized proteins. The Phospholipid's were arranged in a double layer, with the hydrophobic water hating lipid feet facing each other and the water loving phosphate facing outside and inside the cell. The phospholipids looks like a double row of freaky spaghetti with blue meatballs facing out the top and bottoms and short strings of spaghetti noodles falling towards each other. The specialized proteins looked like large oblong ovals of a yellow color whose job was to pull through the molecules the cell needed that would not fit through the phospholipid layer. They both fit together like a diffusable skin on the cell. The status in the cell was hypertonic. Water molecules were constantly moving and bumping into each other. There were more water molecures outside the cell so they spread out into the cell through the phospholipid layer. The cell had enough of a supply of molecules, but was bringing in more, using active transport to bring it in. Specialized proteins used ATP instead of passive transport which works from a high concentration to a low concentration which needed no ATP. Facilitated diffusion was bringing in glucose molecules because the specialized carrier protiens recognized glucose and automaticlly brings it in. But the cell membrane function I remember best is probably the action of endocytosis known as phagocytosis. When I was floating amid a cloud of water molecules, a stretch of cell membrane flexes and jumps out at me and swallows me into the cell trapped in a phospholipid layer. It took me an hour to get out. Somehow the cell maintained homeostasis through all that chaos.
Organelles I Have Known
A stream of vessicles were coming out of a Golgi Body. The Golgi Body was a yellow folded membrane. An amino acid chain went in one end of the Golgi Body, who altered it with starch and water, folded and twisted it into a proper protein shape, and packaged it into a vessicle, which took it either out of the cell to another cell, or like this one, took it to another organelle. A vacuole had a bad habbit of harassing me, hitting me on the head, ouch.
The Rough Endoplasmic Reticulem contains Ribozomes that secrete proteins to other cells, and unattached Ribozomes create proteins used inside the cell. The smooth endoplasmic reticulem creates lipids and fats, and is used to make vessicles. The rough endoplasmic reticulem was very interconnected with the nucleus.
Lysosomes are the recyclers. The lysosome contains digestive enzymes that break down old or broken organelles and makes them usable in new organelles. There are different types of lysosomes. The lysosome appears as a membrane bound sack of enzymes. It is not hurt by its enzymes.
The cytoskeleton are small structures composed of tiny protein structures and microtubululs. It supports and gives structure to the cell and creates pathways for organelles movement. The cytiskeleton was too small to impede my movements.
A vacuole is a large and nearly invisible sack containing water. Have you ever eaten an orange and wondered what the big bubbles of sugary water are? It also holds starch, pigment, and salt. You can find them more in plant cells. As I am telling you, I am presently sitting in a vacuole being bumped by a starch and getting painted by pigments. I am currently an orange-red.
A glucose was facilitatedly diffused through the cell membrane along with a cloud of oxygen it looked like a pentagon with a tail. A specialized protein enzyme inside a roving vacuole that swallowed the glucose creating two pruyruvic acids. These entered into a mitochondria and a carbon broke off and turned into carbon dioxide waste. A high energy electron was released. A carrier molecule took the two carbon acetic acid and attached it to the end of a four carbon structure creating citric acid. The citric acid moved away and broke off one of the carbons, leaving one of the attached. A high energy electron was released and bounced gleefully, burning me a little bit. I frowned and grimaced at it, and it dimmed and darted away. The last carbon was snapped off and floated away as carbon dioxide waste. The four carbon structure returned for another acetic acid and the last high energy electron darted off. The Calvin cycle was complete. The three high energy electrons zipped to a set of six molecules called the Electron Transport Chain. A high energy electron would skip down the six molecules, losing energy as it went. Each molecule it touched would have enough energy from the high energy electron to create one ATP from ADP+P. A full molecule gives thirty-eight ATP. The splitting of the glucose is the first two. And there are six ATP created from breaking a single carbon bond, since there are six molecules in the electron transport chain. There are six carbons in a glucose. Six ATP from each carbon bond, and six carbons, plus two from the first break equal thirty-eight. I swish a fin at my cleverness. The used up electrons would be attached to the oxygen molecule along with two hydrogens, creating a waste product of water which was sent to the chloroplasts.
Searing shafts of light energy will occasionally lance through the cell. One ray of light speared a cholorplast, making it jiggle. I swam through it's membrane through a cloud of outgoing oxygen molecules. Water was streaming into the chloroplast, dragging me in. I saw another spear of light score on a chlorophyll filled thylakoid, out of which danced a high energy elecetron that had been a normal electron until charged by the light energy. The H.E.E. had two ways to go and it danced to the first one and skips down an awaiting Electron Transport Chain, creating six ATPs which waited in a group. The normal electron fell back into one of the thylakoid, where another shaft of light energy zapped it again, making it glow and dance. This is Light Reaction.
I followed it as it gathered up it's six ATP's and went down pathway two to the Calvin Cycle or Dark Reaction. A molecule of Carbon Dioxide imported from the mitochondrian resperation lost it's carbon which was added to a five carbon RuBP(Ribulose biphosphate), creating an unstable six carbon molecule which broke in half, creating two PGA(Phosphoglycenic Acids) which were infused with the energy from the gleeful H.E.E. and it's ATP molecules. The H.E.E. that was used here was replaced in the thylaskoid by an electron from a water molecule with oxygen as a waste product. One of the new PGAL(Phosphoglyceraldahyde), which used to be PGA, was secreted by the chloroplasts as a carbohydrate and the other was turned into a five carbon RUDP to repeat the process. The waste oxygen I accidentally breathed in to complete a very much smaller version of respiration but the cell wall brought in more.
The Nucleus and DNA Replication
The nucleus loomed high above, the control seat of it's little cell world. Rough endoplasmic reticulum draped around it like a billowing gothic cape. It was huge and a little scary. I swam through the cytoplasm, my translucent paw-fins creating eddies in the Endoplasmic Reticulum's gunky membranes.
I was hesitant to enter the great domain. The decision was made for me. A vast wave of Adenine tri-phosphates bore me through a membrane pore or loose outer membrane which fused at the edge of the doorway to the tight inner membrane. Small shafts of pale light highlited the scene. A dark hulk was the nucleolus as it synthesized the Robozomes for Protien making, and sent them out of the nucleus through the protien and phospholipid double fused membrane pore door of the nucleus. Yarny pythonlike strings of cromatin matterial snaked and bobbled like a drunk octopus as thet floated in the gloom. A string of cromatin utangled, spiroling into a long chain of deoxyrionucleic acid. The base pairs of Adenine to thymine and guanine to cytosine are the sets of genentic codes that went on and on. The double helix twisted ladder shape untwisted into a ribbon structured strip of DNA. The edges of the DNA were composed of sugar-phosphate-sugar-phospate, in a picket line. Each held its place with a covalent bond's deathgrip. A special\ protien floated down to unzip the hydrogen bonds, the adenine and thymine had a two hydrogen bond, and guanine and cytosine were connected by three. The special protien traveled down the deoxiribonucleic acid's hydrogen bonded nucleotides and were separated from their opposing mirror partner moleculoes. When one of the special protiens left off, another identicle molecule would continue until the entire long DNA molecule was rent and open down it's entire length. A cloud of small protiens converged on the two half DNA molecules. Matching adenine to thymine and guanine to cytosine, the smallest protien slowly pieced together a complement to the original strand. When the small protiens withdrew, two brand-spanking new DNA molecules re-helixed into strands of cromatin and mixed in with the jumble of their comrades. I had to marvel at the efficiency. All so quickly and with a double check of the nucleotides, my tail created eddies in the cytoplasm.
I swam back into the busy Nucleus huge and scary because I wanted to see if I had missed anything interesting on my last excursion in. It turns out I had. As I swam through the double membrane bedecked by Rough Endoplasmic reticulum, I saw what at first looked like another DNA Replication. But the special protein that was cruszing the flat, untwisted DNA, made a decesive little jump when it hit the speicific code called UAC. It undid it reached either a AUU, AUC, or ACU code that told it to stop. When the little proteins went to compose its opposite sides of the original strand, they only ressurected the right side, using ATP's to snap the sugar-phosphate covelent bonds together and pull off the now-complete RNA ribonucleic acid messenger molecule. The old DNA was then snapped back together whole and well and the new RNA exited by a convienient membrane egress, heading for a ribosome. Just as it leaves, a group of adenine is tacked on the end for the anti outside of Nucleus molecules to munch on so as not to damage RNA sequence.
A Skeletal Protein is Made
A new m-RNA exits the nucleus and floats to a Ribosome. The ribosome grabs onto the m-RNA. The Ribosome is a small structure. Transfer RNA, the nucleus had made earlier grabbed it's specific amino acid and headed for the Ribosome. The t-RNA would match up its anticodon to the proper doce: G-C / C-G / U-A / A-U : U = uracil. The m-RNA would hold the t-RNA until a second t-RNA would come with a different amion acid and grab the first amino acid. The m-RNA would go from one end of the Ribosome throgh the other end along with an amino acid chain that would go to a Golgi Body for processing. I followed it.
The Cataclysm of Mitosis
Suddenly everything was quaking. If I could have fallen down in my liquid environment I would have gladly done so. I watched in horror as the great and mighty nucleus shed it's Rough ER cape. The cell was exiting it's normal placcid interpahse and rocking into prophase.
The Nuclear envolope disintegrated, showing the chromotin as it replicated into two equal strands and the replicaing centrioles. The mother and new daughter centriole went to opposite ends of the cell. With a shudder it left prophase and scrambled into metaphase.
Chromatin X's of mother and identical daughter strands lined up in the middle of the cell as the centrioles sent spindle fibers out and grabbed one of the X's branches. Mathepahse pulled into ananphase.
With a gut-wrenching pull, the centrioles wrenched one of the two Identical chromatin strands away form the equator and each other and toward the opposite poles. Anaphase squeezed into telophase.
A new cell membrane was created as the edges of the cell squeezed off at the equator and pulled into two new, small, cramped cells. I was squeezed out between the newly formed cells.
I smiled and swam away as the two new cells bobbed placidly... I had fun.