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Reflection 11/3/2011

Today in class I learned about glycolsis. The simple explanation of glycolsis is that is the body’s way of breaking down of glucose molecules into essentially 2 pyruvate molecules. Glycosis takes place in the cytoplasm like most metabolic reactions that occur within the cell. It is apart of the anerobic (none oxygen requiring) cellular respiration process of the cell. 

The glucose molecule involved in glycolsis has a chemical composition of  C6H12O6. The process of glycosis is done in 10 steps that use 2 ATP but the outcome of glycosis is 4 ATPs, 2 NADHs and 2 pyruvate molecules/  and of course glucose, 2 ATP. Gylcolsis occurs in 10 steps so that the process is very well regulated within the cell because large amounts of energy are consumed as well as released. If the process was not regulated and broken down the amount of energy that could be released will be so great that all the proteins that make up a person could denature or unfolded and be rendered nonfunctional and the end result would the death of the cells and the organisms. It also done in 10 steps so that the necessary precurors to the next reactions are formed and the process can continue.

Glycosis is as follow:

The first 5 steps requires the use of energy or ATP..

1. Hexokinase enzyme adds a phosphate molecule to the 6-carbon in the glucose molecule to destablized the molecule.

2. Phosphoglucoisomerase converts the glucose 6-phosphate into its isomer fructose 6-phosphate by rearranging the molecules.

3. Phosphofructokinase uses another ATP molecule to transfer a phosphate group to fructose 6-phosphate to form the molecule fructose 1, 6-diphosphate.

4. Aldolase splits the fructose 1, 6-diphosphate molecule into two different sugars.

5. Triose phosphate isomerase converts the molecules dihydroxyacetone phosphate and glyceraldehyde phosphate and the glyceraldehyde is used in the remaining glycosis process.

6.  Triose phosphate dehydrogenase transfers a hydrogen from the glyceraldehyde phosphate NAD+ to form NADH

7. Phosphoglycerokinase transfers a phosphate groups to a molecule of ADP to form ATP.

8. Phosphoglyceromutase moves the phosphate group from the  from the third carbon to the second carbon.

9. Enolase removes a molecule of water from 2-phosphoglyceric acid.

lastly,

10. Pyruvate kinase transfers a phosphate form pyruvic acid and ATP.

 
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Posted by on November 5, 2011 in Uncategorized

 

Lac Operon 10/24/2011

Much of the class discussions have been about/on the structures and operations that occur within the eukaryotes. Today, however, we began a discussion on the gene regulation, whether to transcribe for a protein (gene) or not, of prokaryotic organisms. Unlike eukayotes, prokaryotes have operons. Operons are multiple structural genes that are regulated by a common operator and promoters. This helps prokaryotes to be more efficient since their surface ares is not as large as eukaryotes.

We humans do possess the E.Coli bacteria but it is only present in our intestinal tract. Furthermore, the prokaryote organism E.Coli, like most bacterias, posses a repressed gene know as the lac operon. The lac operon gene is repressed because it is not constantly used but it may be needed with is why the gene has not been completely eliminated. In the presence of glucose, the lac operon is repressed because the sugar of choice are those sugars that are common to animal like glucose.

If for whatever reason glucose is not readily available and the lactose sugar is present it then binds to the repressor molecule and it released from the regulartory site on the lac operon. It is released because the shape of the repressor molecule will change its shape and no longer will be able to bind properly at the operator site. The one RNA polymerase that bacteria have can then bind at the operator site and begin its transcription of mRNA of the lac operon. This mRNA then is then joined by ribosomes and the proteins are made that E.Coli needs in order to break down the lactose into a usable sugar needed for it metabolic functions.

 
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Posted by on October 25, 2011 in Uncategorized

 

Genetic Inheritance Cont… 10/20/2011

We continued to discuss genetic inheritance but this time in greater detail. To throughly understand the concept of inheritance you must first know the difference between a genotype and phenotype. Genotype of a person is the varied genes of a certain trait that you possess along your chromosomes where as the phenotype is the expression of the gene or trait; in simpler terms, phenotype is how you look. Geneticists use punnette squares to show the probability of an offsprings to acquire a particular genotype which will essentially effect the offsprings phenotype. A punnette square can only be used to determine the probability of an offsprings acquiring ONE trait!

If you wanted to determine the acquisition of multiple traits then the best graph to use would be the dihybrid crossing graph.

Although, Gregor Mendal made genetics seem like a simple mathematical equations,9:3:3:1, governed by easy probabilistic occurrence,genetics is far from simple because traits of one characteristics of a person could rest on the same chromosome. Hence, they are not independently assorted whereas traits that are not on the same chromosome are independently assorted, or randomly given to offsprings.

When looking into inheritance, one must take into consideration the fact that some traits display incomplete or codominance characteristics. Incomplete dominance occurs when two parent organism mate and they pass to the offsprings to separate alleles and neither alleles shows complete dominance or expression over the other. In other words, there is a blending of the alleles when the phenotype of the offspring is expressed.

Codominance can also occur. When two parent come together and they pass to the offspring separate alleles that are both dominant and the offsprings expresses both proteins instead of one over the other. The most common example of codominance is blood types. Those individuals that have the AB blood type are the perfect example of an organism expressing codominance. The have the genes to produce both the A and B red blood cell antigen and not just either A or B or no antigen.

 
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Posted by on October 20, 2011 in Uncategorized

 

Class Reflection 10/18/2011

In this class, I learned about the three different types of processing proteins. There are the proteolysis, the glycosylation and the phosphorylation protein. Each protein has a different job and the glycosylation is responsible for the addition of sugar. The phospholrylation is responsible for adding a phosphate group. Lastly, the proteolysis is responsible for directing newly formed proteins to the Golgi apparatus and it is also responsible for the cleaving of polypeptides to allow the fragments to fold into different shapes.

It is possible to inject a gene into another species, which then displays the trait of the other species because of the universal genetic code. Translation, which is a cytosolic process, of RNA and DNA are the same regardless of the species, however, the only variation is that the mechanism of translation may vary. When undergoing translations, cells have a stop codon that initiate termination of protein production and the codon is usually UAG, UAA or UGA!

Genetic expression and experimentation was first done by Gregor Mendal, an Austrian Monk that went with little to no fame at his time of existence. He achieved such experimentation through the work of peas that can produce up to two generation in a one year. He was also responsible for coding, in mathematical terms, the pattern of inheritance.

 
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Posted by on October 19, 2011 in Uncategorized

 

POUNCIN’ AROUND THE CELL

One day Johnny was not feeling to well but he decided to go to school anyway. One his walk to school, Johnny ran into his friend Randy and they continued their 2 block walk to school and conversed along the way. When they got to school Johnny realized that they had 20 minutes until their first class was to start so he extended an invitation to Randy to go to breakfast. Randy accepted as he knew it was chicken biscuit day in the cafeteria. They went through the line and got their trays and then sat down to eat. Without a moments notice, Johnny sneezed on Randy as he was eating the last bite of his chicken biscuit. Johnny apologized and they threw away their trays and headed off to homeroom.

In the story of Pounce the Panther begins….

After Johnny’s sneeze, Pounce was transferred from Johnny to Randy and he was looking for a new place to dwell and call home. While floating carelessly through Randy’s bloodstream, Pounce noticed he spherical shaped structure and as his curiosity began to spark he made his approach to examine this new “thing.” As got closer to the structure he realized that not a lot of things were go into the structure or out of it. However, what he deduced from the things that he saw going on with this structure was that most of the same compounds were going in and most of the same molecules were coming out of it. He was fascinated so he decided to call it the membrane because he rationalized that it determined what when into the cell and what came out of it and that had to do this to maintain stability within its borders. He saw that it was a phospholipids bilayer that means it was hydrophilic and hydrophobic. He also notices that it had channels and pores that appeared to be made up of proteins. As Pounce walked around the cell to explore it more, he accidentally brushed up against the mediate endocytosis receptor. Almost immediately, the receptor began to change its shape as Pounce was the Ligand for it.

Pounce transcended down this tunnel until eventually he was within the very membrane of the cell. While inside, he realized that he was moving around the cell by fluid. He called this fluid the Cytosol. The Cytosol was with in the cytoplasm that extended throughout the entire cell and it appeared to house all the internal structures of the cell except for the nucleus. The Cytosol helps transport things around the cell and it is where reactions of the cell seem to take place. As he was transported further around the cell he noticed why the cell has it particular spherical shape. There were filaments that interlocked and connected in order to give the cell shape and it also aided in the movement of the cell around and across the human body and bloodstream.

As Pounce was moving around the cell, he saw a lot of the structures of it. He saw a structure that he called the lysosome. The lysosome was the like the sanitation worker of the cell. It picked up all the waste products like proteins, nucleotides, lipids, phospholipids, and the can remove carbohydrate, sulfate, or phosphate groups from a molecule by digesting them with the enzymes that it houses.

Pounce’s smooth ride began to get a little rougher. He was in a region in the cell that was surrounded by a ton of what he called ribosomes. He decided to call this are the Rough Endoplasmic Reticulum (RER). This region of the cell is the manufacturing site for lipids and many proteins. It is also responsible for the modification of proteins. It can viewed as network of membranes that were enclosed flattened tubules that also appear to be connect to the nucleus because it does surround the nucleus.

Ponces ride got a little smoother as he entered a separate network of flattened tubules. He thought there were the same but this area just did not have any ribosomes so he called this region the smooth endoplasmic reticulum. There were a lot with lipid manufacturing and metabolism. There always was some steroid and hormone production.

As Pounce continued on his journey of the cell he came into contact with the biggest organelle within the cell. It was very dense and dark and had lots of holes that appeared to look like pores. He wanted to explore it but he was a bit timid and scared by its size. He thought back to what his mother had said, “never be afraid to learn,” so he snapped out of his scared trance and quickly went looking around to find a way through the pores of the nucleus. THERE IT WAS, Pounces way in! Pounce saw that one of the nuclear pores were about to open to allow for an ion to pass through. He ran as fast as he could and then jumped and grabbed a hold of one corner of the ion and followed it through the passing of this nuclear pore, protein channel.  While in the nuclear pore, Pounced discovered that this holey membrane was actually TWO cellular membranes. It had both and inner and outer member that were exactly parallel to each other.  

After his arrival into the nucleus, he was surprised just how large the nuclear membrane completely enclosed the nucleus. After he got over his awe about the nuclear membrane’s size he looked around and realized that area, nucleolus, almost appeared to be manufacturing factory. Everywhere he looked, he could see that rRNA and ribosomes were being assembled.  After all of this, he concluded that this is where all of the genetic materials of the cells were housed, maintain and protected and that the nuclear membrane served to separates the cell’s genetic material from the cytoplasm and cytosol. It was hard to get into the cell now that Pounce had quenched his thirst of curiosity and now he wanted to get back out of the nucleus so that he could explore just one last structure that he failed to.  In the distance, he saw completed tRNA that was ready to be transported into the cytosol so that it could be made into a protein. He ran like an Olympic track winner until he could grab a hold of it and be transported back through the nuclear pores. YES!!! He made it and after a relatively modest time travelling through the channel, he was now back into the cytosol and off he went to the Mitochondria.

 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 After his arrival to the mitchondria, Pounced noticed that it was the power house of the cell. It provided the cell with ATP or the fuel that is usable by the cell fuel all the reactions of the cell and keep life living. There was an electrochemical gradient of H+ ions that he called the Proton Motive Force. It was a double membrane that had narrow folds within the outer membrane. Pounce also noticed that the mitochondria had its own ribosome, DNA and made its owns protein and that it did not appear to need the cell to replicate or grow. This got Pounce wondering back to his biology class. Maybe the mitchondria was at some point an entrirely separate organism. As a matter of fact, it was! He remembered his biology teacher going over a concept called endosymbiosis. That is when one organism lives within another organisms and one organisms transfers some if it’s DNA over the now host organism and loses gets rid of some of its original DNA and functions so that the two different organisms can combine and both organism now have a mutual relationship with each other. WOW! The mitochondrias were awesome but it was time from Pounce to head over to the Golgi apparatus.  

 

Lastly, the golgi apparatus is the organelle in the cell that processes and packages all of the ready proteins. It functions as the post office of the cell by stamping the proteins with its required postage (glycosylation, etc), and finally shipping the protein to where it needs to be and it is also responsible for the recycling of processing proteins to be used again. It is a structures that has stacked membranes between the RER and the cell membranes

http://www.sciencecontrol.com/wp-content/uploads/2011/05/Golgi-Apparatus-Function.gif

After all of that exploring Pounce realized that he was homesick and hungry so he grabbed on to water molecule and headed out of the cell.

 
 
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Posted by on October 16, 2011 in Uncategorized