DNA

Authors Note: I chose to write about the topic of DNA. The story behind this is that a few weeks ago I decided to write a report on the double helix. That's when I found out how hard it is to write a report about a shape and thought that a report on DNA would be simpler. I was right. My biggest focus when writing this was transitions.

DNA is, without a doubt, the most amazing of natures creations. Each DNA molecule contains the information and instruction on how to make an organism, including you. DNA is responsible for the characteristics of an organism from appearance to the way someone behaves. Even aging has been programmed into our DNA. Without our DNA, we probably wouldn’t even be here. There’s a lot to know about DNA. What better place to begin than the beginning?

DNA was first discovered in 1869 by Friedrich Miescher in Switzerland. When he discovered it in White blood cells he gave it the name “nuclein”. However, the real beginning of this study began in 1865 when Gregor Mendel conducted his pea plant experiments in heredity leading to Mendel laws of heredity. These laws are the law of segregation, the law of independent assortment and the law of dominance. While not the actual discovery of DNA, Mendel’s research was the beginning of the study of genetics. Unfortunately, Mendel’s research was not accepted until the early 1900s when it was rediscovered by Carl Correns, Hugo de Vries and Erich von Tschermak-Seysenegg. Many new discoveries followed, but it wasn’t until 1951, almost 80 years after Miescher’s discovery, that anyone actually wondered what DNA looked like.

These people were Rosalind Franklin, Francis Crick and James Watson. Franklin used a technique called x-ray diffraction to take a photo of a DNA molecule. The photo suggested that DNA had a helical shape. After seeing Franklins photo, Watson and Crick created a three dimentional model of a DNA double helix. A double helix is, as its name suggests, a shape made up of two helices curving around the same axis. The DNA double helix has been described by many to have an appearance similar to that of a ladder, two strands connected by many “rungs”. It has been observed that many cells and molecules in our body tend to take on a helical form. However, DNA is the only double helix. Why does DNA take on its twisted form?

The answer might lie in its makeup. DNA is made of things called nucleotides. Each nucleotide is made of phosphate, sugar and a base. There are four bases in DNA: adenine, thymine, guanine and cytosine. The sugar and phosphate make up the two strands of a DNA molecule and the rungs are made of two bases each. A base will only connect to a complementary base. The complement of adenine is thymine and guanines complement is cytosine. The double helical shape of a DNA molecule might have something to do with how these components react to water. Sugar and phosphate are hydrophilic and attract water. The bases, however, are hydrophobic and are repelled by water. This is a problem as 80% of the human body is water. The shape of DNA might be designed to keep water away from the hydrophobic bases by only exposing the hydrophilic strands. What is the point of the bases though? Why are they needed?

They are needed because they make up the genetic code. A gene is a long string of nucleotides with information about creating a specific trait or characteristic. The human body contains a lot of DNA, which allows for many genes and many characteristics. The bases are arranged in groups of three. These groups are called codons. Inside the core of a cell, called the nucleus, one side, and it doesn’t matter which, of the DNA double helix is copied by mRNA or messenger RNA. Once the copy is made, the mRNA leaves the nucleus and goes to a part of the cell called the cytoplasm. In the cytoplasm is a cell subunit called the ribosome. The mRNA is fed through the ribosome one codon at a time. Inside the ribosome, tRNA, or transport RNA, carrying an amino acid from the cytoplasm, matches the base code on the mRNA with the complementary codon. The tRNA then releases the corresponding amino acid into a growing “chain” of amino acids. Once this chain grows big enough, it becomes a new protein molecule. RNA is also used in a different way.

It is used in the process of DNA replication. DNA replicates its self when a cell divides. To begin the process, an enzyme called a helicase. The helicase splits the DNA molecule in half by breaking the hydrogen bonds between the bases and creates a structure called a replication fork. Both strands are coated with Single Strand DNA Binding protein or SSB. This keeps the strands from rejoining. In a DNA molecule, each of the two strands has a 3’ and 5’, or three prime and five prime side and a DNA strand always moves in what’s called the 5’ to 3’ direction. The 5’ side of one strand of a DNA molecule is in the opposite direction than the 5’ of the other strand. In other words the strands are opposite of each other. DNA replication can only happen in the 5’ to 3’ direction and can’t start from nothing. It needs a starting point with an open 3’ end. This is where RNA comes in. RNA makes what’s called a primer. This primer creates a starting point for something called a DNA polymerase. A DNA polymerase is responsible for the creation of new DNA. In the process of replication each strand has a name. The strand moving away from the replication for is called the leading strand. The one moving into the replication fork is called the lagging strand. The leading strand needs only one RNA primer, but the lagging strand needs multiple primers. On the lagging strand the DNA polymerase will only create make a strand from one primer to the next, but won’t connect them, resulting in many fragments of a strand instead on one while one. These are called Okazaki fragments. After a RNA primer has been used, it must be removed. This task is done by an RNase H. Then the polymerase fills in the gaps where the primers used to be. Then a DNA ligase joins the Okazaki fragments. The end result is two new DNA molecules. But what would happen if a mistake was made in the replication process?

The most probable outcome would be a genetic mutation. This is caused by a change in the genetic code. That means something changed in the arrangement of the bases. The most common forms of mutation are the addition, removal or substitution of a base. the effects of mutation could be harmful or they can improve a trait of a person. They can even do nothing at all. Usually only one base is affected, but this one change can cause conditions like a disease called sickle cell disease. This condition results from a mutation that changes the codon for Glutamic amino acid to the codon for valine. This causes the shape of red blood cells to change. These new cells don’t carry oxygen as well as normal cells and are more prone to clotting. Mistakes don’t just occur in the replication process. They happen when mRNA copies a DNA strand or when DNA repairs its self when damaged and it can even happen as a result of external sources.

An external physical or chemical agent that causes mutation is called a mutagen. Examples of mutagens are UV radiation and x-rays.

The study of genetics has come a long way since Mendel’s pea plants. Things like genetic engineering and using DNA to track criminals are some of the possibilities. These kinds of things would’ve been thought impossible in Mendel’s time. Imagine what the research and study of DNA will accomplish in the future.

Spaceship One

 

Commercial spaceflight has been in the interest of humans since the first probes sent to space, an interest that has made its way into most sci-fi shows, games and books. This dream is becoming reality, thanks to a small craft known as a spaceplane called Spaceship One.

Spaceship One was the first commercial spaceflight and also the first private spacecraft. It was a joint operation between Paul Allan, who funded the entire project, and Burt Rutan and his aviation company, Scaled Composites. Spaceship One is not a true spaceship, as it only achieves low orbit for about five minutes. It cannot achieve this low orbit by its self and is instead carried into the air by a jet built specifically for the task called the White Knight. White Knight was also used to train the pilots of Spaceship One

In 2004 Spaceship One was awarded the Ansari X prize for being the first commercial spacecraft to make two spaceflights in a time period of two weeks. The prize was ten million dollars, but this is only two fifths of what it cost to actually build the craft. It was piloted by Mike Melvill.

Another flight was supposed to be made, but Rutan didn’t want to risk damaging the craft. It was later taken to the Oshkosh EAA airshow in Wisconsin in 2005, and afterwards to the Smithsonian Air and Space Museum.

Afterwards, In a co-venture between Scaled Composites and Virgin Galactic, Spaceship two was planned to be used for “Space tourism”. Five of these model craft are being, or have already been constructed, the first one completed being, or to be called the VSS Enterprise. These craft will be double the size of Spaceship one. It is also possible that a Spaceship Three is under discussion.

The dream of commercial spaceflight is finally a reality, for anyone who has 200,000 dollars. This is pretty expensive, but reasonable for this point in time, when the only other way to go to space is by becoming an astronaut. The price is bound to come down eventually. Spaceship One was an important spacecraft in modern history, depending on point of view. It’s pretty much certain there are people who don’t think much of Spaceship Ones achievements. Nonetheless, Spaceship One helped open doorways into what some might call the future. In a way, Spaceship One started to bridge the gap between science fiction and science fact.

Ireland

Ireland, or the Emerald Isle as some call it, is located just west of the UK and consist of 32 counties, the northernmost 6 actually part of the United Kingdom. Because of this, there have been tensions between the two parts. The official language of Ireland is Gaeilge, but if you don’t speak Gaeilge, that’s okay, as English is also spoken in every part of the country.

Ireland has a few notable landmarks some are noticed because of their natural beauty, others because of historical value. Here are some important Irish landmarks.

                St. Patrick’s cathedral

Said to be the oldest Christian site in Ireland and the place where St. Patrick is thought to have baptized converts, St. Patrick’s cathedral was the church of St. Patrick (as if I didn’t already say that name enough, and as if it wasn’t obvious enough). The original structure was made of wood, but because of the fear of the church collapsing, it was rebuilt using stone. As a result, most of the building and interior decorating dates back to the Victorian era.

                Blarney Stone/castle

Who hasn’t heard of the Blarney stone? If you haven’t heard of the Blarney stone, you need to get out more. If you haven’t heard of the Blarney castle, I can kind of understand that. The stone was a gift from Robert the Bruce, and the castle was built around it, with the stone located in the battlements, in 1446. If you’ve heard of the Blarney stone, you should know that if you kiss the Blarney stone you get good luck. I wouldn’t recommend it though, as it has become one of the most unsanitary pieces of history in the world.

                Cliffs of Moher

The cliffs of Moher are one of the most famous landmarks in Ireland, their minimal height being about 120 feet above sea level, maximum height just over 200 feet. More than 1 million people come to see the cliffs of Moher each year. They must make sure they are careful, as there is no barrier between the visitors and the sheer 100-200 foot drop. They take their name from an old fort called Moher ui Ruidhin, built as a lookout tower during the Napoleonic wars.

Recently, Ireland has gone from agriculture to a so called “modern knowledge economy”. Ireland is, in terms of global domestic product, one of the wealthiest countries in Europe, ranking 5^th out of 28. However, in terms of global national product, is somewhat lacking, despite extreme growth over the last couple of years. In a recent study, Ireland is said to have, at this point in time, the best “quality of life” for the citizens than any other country.

Like everywhere else, Ireland produces it’s own natural resources for use in the country, or to be exported. Irelands most common natural resources are natural gasses, zinc, peat, copper, lead, petroleum, dolomite, barite, limestone and gypsum(not in any specific order). Also common are many forms of agriculture like fish farming and other livestock. There’s also mining and foresting.

Like other cultures, Ireland has its own unique set of traditions. These range from their language to their sports and even their music.

The Irish language descended from Celtic a long time ago, and is part of a group of similar languages from a similar origin. This group is called Q-Celtic. After the English conquered Ireland as part of the United Kingdom, the language of Ireland started to decline, and latter more so due to famine and mass emigration. In 1893 in an attempt to save the language, two men named Douglas Hyde and Eoin Mac Neill created the gaelic language. Today more than 1,500,000 people are fluent in Gaelic and about half that number use it on a daily basis.

The Irish are avid sports fans, and have their share of unique sports, like we Americans play football and baseball and such. For example, the game of traditional Irish hurling is said to be as old as known Irish history itself. In this sport, there is a ball, similar to a baseball in size and hardness, and fifteen players all armed with sticks called a hurl. The field is about 137 meters long, and on each side, there is a pitch that the ball must be taken to in order to score. The ball can be held for only 4 steps, then it must be hit with the hurl, kicked or slapped. Contact is allowed, but there is no protective gear while playing. There is also the game of Gaelic football, which is in some ways similar to hurling, but most often described as a mix between soccer and rugby. Like hurling, each team consists if 15 players and when in possession of the ball, the player is allowed 4 steps before kicking or “hand passing” (a striking motion with the hand or fist) the ball. Another option for players who have taken their fourth step is to “solo” the ball, or drop the ball onto the foot and kick it back into their hands. This move can only be used once per carry before passing the ball to someone else. At the end of the field is a crossbar that the ball is either put over or under. If the ball is put over the crossbar, the team scores 1 point. If it goes under the crossbar, in certain circumstances, the team can score a goal, worth three points.

Irish music is important to Irish culture. Many traditional Irish songs tell a story, making them more appealing so I hear. It also has a unique sound, because there are instruments that are used specifically for this kind of music. Like the Uillean pipes and the Bodhran drum. Stories told by Irish music can be life stories or the history of the Irish altogether. Now days, there are bands that mix traditional Irish music with rock music to get a new sound, but in these songs, the original idea of Irish music has not been forgotten.

The climate of Ireland is mostly sunny, but there are still plenty of rainstorms. It really depends on the season. Spring and summer are usually sunny, but still a decent amount of rain and in fall and winter, its more the opposite. To prove how quick the weather can change in Ireland, it can be sunny, then rainy and then sunny again in a matter of minutes. It’s usually very warm in Ireland, only dropping to about 40 degrees in the winter.

Due to its isolation from the rest of Europe, Ireland has a less diverse collection of animals than other locations. There are only 55 species of mammal and only about 26 of them live on land that are actually native to Ireland. There are about 400 different species of bird in Ireland, most of which are migratory. There are no snakes in Ireland at all, and there is only one species of lizard, known as the common lizard. Some examples of animals that are now extinct in Ireland are the great Auk, the Irish Elk, and wolves. Today, about 12% of Ireland is covered in forest. Ireland is ranked the 42^nd most forested country in Europe on a list of 55. The most common kinds of forest are Oak, Pine and Birch. Now days most of Ireland is covered in large pastures containing many different kinds of wildflower.

 Ireland is an interesting place with an interesting history and a lot of culture(nothing like you see on T.V.), definitely something worth looking up if you have the time.

Where no man has gone before...continued

As the vessel pulled away from Earth’s gravitational pull, and its 10 minute flight to the test zone began, a feeling of relief traveled through the bridge. Sovereign was to meet the science station Atlas and the heavy carrier Hyperion just past Io. If the Sovereign arrived at all, that was one test completed, the engines worked. And arrive they did, one minute ahead of schedule, not that the extra minute mattered. What did matter is what everyone saw when they arrived, and what they saw was half a space station and a heavy carrier being attacked by numerous large spacecraft, and there was a 99% probability it wasn’t part of the test (as calculated by the onboard computer). Part of the test or not, it was the Sovereigns job to blast the unknown craft, but first it had to somehow stop their attack on the Hyperion. It wasn’t hard to spot out the flagship. It was probably the largest and most heavily armed ship in the group. With pulse cannons on full charge and antimatter charges loaded, Sovereign hit the supposed flagship with everything it had.(to be continued...again)

Alternate energy

 Authors note: I wrote this piece because writing on my blog has been a bit lacking. The idea came from my support group when we started a project on this subject but never finished.

One of the biggest issues today is the need for fossil fuels like oil and coal for power and electricity generation, seeing as combustion powered generators, but there are many other sources of power that require more renewable resources like wind or water(lots and lots of water) and are "environmentally friendly". Here are some examples of such sources of power, but first.I think you should know where the electricity generator came from. The original electricity generator was a simple a loop of wire or copper disc between two magnetic poles. This method was invented by Michael Faraday in the late 1820s to early 1830s, and is still in use today. Finally, before I get into alternate energy, I feel I should explain the normal combustion generator.

Combustion powered generator

This is the usual power generator. Coal is mined and transported to a large burner that, obviously, burns the coal to create heat. Above this burner is a pipe full of water which will heat up until it turns to steam. This steam travels along more pipes until it reaches a turbine in the center area of the plant. The steam causes this turbine to turn and that powers an electricity generator. The smoke from the burning coal is expelled through giant smoke stacks.

Geothermal power

Geothermal power uses the heat of the earth to generate power. It does this by using the heat to turn water into steam. There are three kinds of geothermal power: Dry steam plants, Flash steam plants and Binary cycle plants. Dry steam plants are the oldest kind of geothermal power, in which the steam is pumped directly into the generator and causes the turbine to rotate, creating electricity. Flash steam plants work by keeping the turbine chamber at a lower pressure than the rest of the system. When the water is pumped into the turbine chamber, some is instantly vaporized into steam to make the turbine rotate. In binary cycle plants, the same water is continually run through the process while the steam is run through a separate pipe. Both pipes are run through a heat exchanger, heating up the water inside the system into steam and the steam in the pipes cools and condenses back into water that is pumped back into the ground. The steam then goes through the familiar process of rotating the turbine before returning to a liquid state. Geothermal power is cheap and environmentally friendly because they run off heated water and give off almost no emissions apart from excess steam. As the water is pumped back into the reservoir, geothermal power is a renewable resource. Traditional coal power plants have an availability of about 75% while geothermal plants are over 90%. Geothermal power is generated 24/7/365. And the heat of the earth is virtually unlimited.

Wind energy

Wind energy is relatively simple. Wind is used to turn a giant turbine which, in turn, creates power. As wind is a non perishable resource, it will obviously never run out. The largest problem I see with wind power is that it’s not always windy. No wind=no power generation. Also. To generate a sufficient amount of power for a large population, a large “wind farm is needed, taking up a lot of space. Wind power is a very environmentally friendly power source as there are no emissions and it runs on a natural power source. Inside a wind turbine, the wind turns the turbine, the big propeller thing in front. The turbine powers the generator inside the nacelle and creates the power. The wind also activates this device on top of the nacelle that monitors wind speed and sends the info to a device called the controller, which keeps the turbine rotation at a safe speed

Hydro power

Hydro power is a renewable power source that operates by water power. Unlike geothermal power, which heats water into steam, hydro power uses the water flow to turn the turbine. We harness hydropower by building giant dams, like Hoover dam. It works like this. The dam creates a reservoir of water. Water then travels down a tunnel in the dam which leads to the turbine which powers the generator and creates power. Creating the dam and reservoir could be harmful to the environment but after that, it’s pretty environmentally friendly and creates massive amounts of power. It’s renewable because of the water cycle, which replenishes the reservoir when it rains.

Nuclear power

Nuclear power works through the process of nuclear fission. Highly refined uranium is broken down at the atomic level creating 2 things: energy and heat. The heat is used in the nuclear power process. The heat causes water in a pipe that runs through the reactor core to heat up. This heated water then runs through another pipe which itself runs through a chamber full of more water. This chamber heats up and turns the water to steam which powers a turbine. The steam then condenses back into water and accumulates at the bottom of the turbine chamber. The giant towers we see at nuclear plants are called cooling towers. These also contain water, which is pumped through another pipe into the turbine chamber to cool the condensed water so it can be cycled through again. The smoke that comes from these towers is not actually smoke, but more steam. Out of all these sources, nuclear is the only one that is non renewable.