I checked out the animations for various links, including Vitamin C, Folic Acid and DNA replication to name a few.
And while I liked the visuals, it would have been more helpful if there was descriptive audio as well…then the animations would have had more impact, the content would have had more meaning and it would make more of an impression to the student and be remembered longer.
Monday, April 19, 2010
Week 9: Definitions “Chemistry of Life”
It seems that like with most things, beliefs are based on the perceptions of whoever is doing the “seeing”. And taken in that spirit, all of the definitions apply, individually; and taken as a whole, collectively.
Personally, I like the very first one: Biochemistry is the chemistry of life. Simple, short, inclusive of all live forms and to the point!
Personally, I like the very first one: Biochemistry is the chemistry of life. Simple, short, inclusive of all live forms and to the point!
Week 9: Ethics of Gene Therapy
Gene therapy is the “insertion of genes into an individual’s cells and tissues to treat a disease, and hereditary diseases in which a defective, mutant allele is replaced with a functional one.” That being said, the trouble is trying to get the gene in the right place. This technology has already been used with some success, as in the case we read about in class where a young girl was born with SCID, a rare genetic disease that essentially meant she lacked a healthy immune system. This therapy allowed this young woman to ultimately lead a relatively healthy life, which would have been impossible without this therapy (she would have been relegated to live life as another “bubble baby”).
However, since human gene therapy is in its infancy and very complex, there are many issues from various perspectives (legal, biological, medical, philosophical, and religious to name a few) that need to be taken into consideration moving forward.
Also, there are currently various methods for getting the gene into the right location…including inserting a normal gene into a nonspecific location (this is most common), swapping one specific gene for another, genes can be repaired through selective reverse mutation (whatever that is!) and through ‘regulation’ (turning the gene on or off)…all of these approaches will require further rigorous development and experimentation to fully develop the procedures.
Then, there is the issue of the vectors for getting genes into place. Viruses are one of the current methods used to insert genetic materials into their ‘host’; however, the problems with this approach are many…beginning with: how do we know that the virus takes the gene to the place it need to go? Then, there is the issue of preventing undesirable effects, and insuring that the new gene won’t disrupt any of the already existent genes in the genome.
And if those weren’t enough of a red flag for consideration of this technology, there is always the specter of abuse of the power this technology wields, be it for creating ‘designer babies’ -or- using it for less than beneficial purposes, such as a weapon for military purposes. In fact, it has been suggested, that it is just this sort of genetic tinkering that created Lyme’s disease (suspected to be a genetic distortion of Syphilis, with which it shares common etiology and symptoms).
And yet, if we were that young girl, living in a bubble, who wouldn’t leap at the chance for a relatively ‘normal’ life…regardless of the potential cost? This therapy is too young at present and needs much more oversight and contemplation moving forward.
However, since human gene therapy is in its infancy and very complex, there are many issues from various perspectives (legal, biological, medical, philosophical, and religious to name a few) that need to be taken into consideration moving forward.
Also, there are currently various methods for getting the gene into the right location…including inserting a normal gene into a nonspecific location (this is most common), swapping one specific gene for another, genes can be repaired through selective reverse mutation (whatever that is!) and through ‘regulation’ (turning the gene on or off)…all of these approaches will require further rigorous development and experimentation to fully develop the procedures.
Then, there is the issue of the vectors for getting genes into place. Viruses are one of the current methods used to insert genetic materials into their ‘host’; however, the problems with this approach are many…beginning with: how do we know that the virus takes the gene to the place it need to go? Then, there is the issue of preventing undesirable effects, and insuring that the new gene won’t disrupt any of the already existent genes in the genome.
And if those weren’t enough of a red flag for consideration of this technology, there is always the specter of abuse of the power this technology wields, be it for creating ‘designer babies’ -or- using it for less than beneficial purposes, such as a weapon for military purposes. In fact, it has been suggested, that it is just this sort of genetic tinkering that created Lyme’s disease (suspected to be a genetic distortion of Syphilis, with which it shares common etiology and symptoms).
And yet, if we were that young girl, living in a bubble, who wouldn’t leap at the chance for a relatively ‘normal’ life…regardless of the potential cost? This therapy is too young at present and needs much more oversight and contemplation moving forward.
Week 8: Semiconductor- Silicon
Name: SiliconSymbol: Si
Atomic number: 14
Atomic weight: 28.0855 (3)
Standard state: solid at 298 K
Group in periodic table: 14
Group name: None
Period in periodic table: 3
Block in periodic table: p-block
Color: Dark grey with bluish tinge
Classification: Semi-metallic
Silicon is present in the sun and stars and is a principal component of a class of meteorites known as aerolites. Silicon makes up 25.7% of the earth's crust by weight, and is the second most abundant element, exceeded only by oxygen. It is found largely as silicon oxides such as sand (silica), quartz, rock crystal, amethyst, agate, flint, jasper and opal. Silicon is found also in minerals such as asbestos, feldspar, clay and mica.
Silicon is important in plant and animal life. Diatoms in both fresh and salt water extract silica from the water to use as a component of their cell walls. Silicon is an important ingredient in steel. Silicon carbide is one of the most important abrasives. Workers in environments where silicaceous dust is breathed may develop a serious lung disease known as silicosis.
Both silicon and (in certain aspects) carbon are semiconductors, readily either donating or sharing their four outer electrons allowing many different forms of chemical bonding.
Measured by mass, silicon makes up 25.7% of the Earth's crust and is the second most abundant element in the crust, after oxygen. As the second most abundant element in the earth's crust, silicon is vital to the construction industry as a principal constituent of natural stone, glass, concrete and cement. Silicon's greatest impact on the modern world's economy and lifestyle has resulted from silicon wafers used as substrates in the manufacture of discrete electronic devices such as power transistors, and in the development of integrated circuits such as computer chips.
Week 7: What is a mole?
According to this article, “the mole was determined by experiments, where the standard temperature chosen is 25 degrees C. and the pressure on the gas is chosen as one atmosphere or 760 millimeters of mercury. While there is nothing special about these values, the temperature is about average room temperature and the pressure is average atmospheric pressure at sea level. It is only important that everyone doing the experiments uses the same temperature and the same pressure (or makes appropriate corrections). It was eventually shown that a Gram Molecular Weight of a gas, at standard temperature and pressure, would occupy 22.4 liters of volume. Or saying it the other way, 22.4 liters of a gas at standard temperature and pressure contains the number of molecules that weigh as much as the molecular weight of the gas expressed in grams.”
The next logical question to ask is: "What is that number of molecules that weighs in grams what the molecule weighs in relative atomic weight units?" The number, named after Avogadro, is 6.0221367 x 10 exp23, is a very large number, indeed. This is the number of molecules in 22.4 liters of gas at standard temperature and pressure, but it is also the number of molecules in a sample of any material that weighs as much as the molecular weight of the substance expressed in grams. A Gram Molecular Weight of any substance contains Avogadro's number of molecules.
The idea of a MOLE is a very useful concept, since it allows you to relate the weight of the material to the number of molecules in that weight. The mole idea also allows you to combine equal amounts (numbers of molecules in each) of two compounds. If you have a gram molecular weight of one compound and a gram molecular weight of another compound, there are equal numbers of molecules in the two weights. If you wanted the two compounds to combine so there was one molecule of each material available to combine with every molecule of the other compound, then mixing the two gram molecular weights would create this result.
"The mole is the amount of substance of a system which contains as many elementary entities as there are atoms in 0.012 kilograms of carbon 12." As so defined, the mole became a key unit (fundamental unit) of the International System of Weights and Measures (aka Metric System) adopted worldwide. As such the mole is technical unit used mainly by chemists, chemical engineers, ceramic engineers, and potters…for potters, the mole is an essential notion of glaze technology, a division of applied chemistry, or chemical engineering, ceramics branch. Who knew!
The next logical question to ask is: "What is that number of molecules that weighs in grams what the molecule weighs in relative atomic weight units?" The number, named after Avogadro, is 6.0221367 x 10 exp23, is a very large number, indeed. This is the number of molecules in 22.4 liters of gas at standard temperature and pressure, but it is also the number of molecules in a sample of any material that weighs as much as the molecular weight of the substance expressed in grams. A Gram Molecular Weight of any substance contains Avogadro's number of molecules.
The idea of a MOLE is a very useful concept, since it allows you to relate the weight of the material to the number of molecules in that weight. The mole idea also allows you to combine equal amounts (numbers of molecules in each) of two compounds. If you have a gram molecular weight of one compound and a gram molecular weight of another compound, there are equal numbers of molecules in the two weights. If you wanted the two compounds to combine so there was one molecule of each material available to combine with every molecule of the other compound, then mixing the two gram molecular weights would create this result.
"The mole is the amount of substance of a system which contains as many elementary entities as there are atoms in 0.012 kilograms of carbon 12." As so defined, the mole became a key unit (fundamental unit) of the International System of Weights and Measures (aka Metric System) adopted worldwide. As such the mole is technical unit used mainly by chemists, chemical engineers, ceramic engineers, and potters…for potters, the mole is an essential notion of glaze technology, a division of applied chemistry, or chemical engineering, ceramics branch. Who knew!
Week 7: Avogadro’s number…
Avogadro had an interest in math and physics and combined those interests when he became the first chair of mathematical physics at the University of Turin.
In 1811 Avogadro published an article that proposed his famous hypothesis, and drew the distinction between the molecule and the atom, which pointed out that Dalton had confused the two. In what is now known as Avogadro’s Principle, he hypothesized that equal volumes of gases, at the same temperature and pressure, contain equal numbers of molecules.
In the example shown in the link testing Avogadro’s hypothesis, we see that there are two volumes of Hydrogen and one volume of Oxygen, which produce 2 volumes of water molecules. Further, we notice that each container has the same number of molecules in it to begin with. So, we can conclude that the ratio is 2 hydrogen to 1 oxygen and we end up with 2 volumes of water molecules, and nothing left over.
In 1811 Avogadro published an article that proposed his famous hypothesis, and drew the distinction between the molecule and the atom, which pointed out that Dalton had confused the two. In what is now known as Avogadro’s Principle, he hypothesized that equal volumes of gases, at the same temperature and pressure, contain equal numbers of molecules.
In the example shown in the link testing Avogadro’s hypothesis, we see that there are two volumes of Hydrogen and one volume of Oxygen, which produce 2 volumes of water molecules. Further, we notice that each container has the same number of molecules in it to begin with. So, we can conclude that the ratio is 2 hydrogen to 1 oxygen and we end up with 2 volumes of water molecules, and nothing left over.
Week 7: Alkali Earth Metal - Beryllium
Name: Berrylium
Symbol: Be
Atomic number: 4
Atomic weight: 9.012182(3)
Group in periodic table: 2
Group name: Alkali Earth Metal
Period in periodic table: 2
Block in periodic table: s
Color: white-grey metallic
Beryllium is found naturally only combined with other elements in minerals. Notable gemstones which contain beryllium include beryl (aquamarine, emerald) and chrysoberyl. The free element is a steel-gray, strong, lightweight brittle alkaline earth metal. It is primarily used as a hardening agent in alloys, notably beryllium copper.
The name beryllium comes from the Greek which means to "to become pale," in reference to the pale semiprecious gemstone beryl. Beryllium is a constituent of about 100 out of about 4000 known minerals and precious forms of beryl are aquamarine, bixbite and emerald.
Because of its low atomic number and very low absorption for X-rays, the oldest and still one of the most important applications of beryllium is in radiation windows for X-ray tubes. Also, due to its low atomic number, beryllium is almost transparent to energetic particles. Therefore it is used to build the beam pipe around the collision region in collider particle physics experiments. Notably all four main detector experiments at the Large Hadron Collider accelerator use a beryllium beam-pipe.
Beryllium has one of the highest melting points of the light metals. Because of its stiffness, light weight, and dimensional stability over a wide temperature range, beryllium metal is used for lightweight structural components in the defense and aerospace industries in high-speed aircraft, missiles, space vehicles and communication satellites. Several liquid-fuel rockets use nozzles of pure beryllium.
Commercial use of beryllium metal presents technical challenges due to the toxicity (especially by inhalation) of beryllium-containing dusts. Beryllium produces a direct corrosive effect to tissue, and can cause a chronic life-threatening allergic disease called berylliosis in susceptible persons.
Beryllium is a relatively rare element in both the Earth and the universe. The element is not known to be necessary or useful for either plant or animal life.
Symbol: Be
Atomic number: 4
Atomic weight: 9.012182(3)
Group in periodic table: 2
Group name: Alkali Earth Metal
Period in periodic table: 2
Block in periodic table: s
Color: white-grey metallic
Beryllium is found naturally only combined with other elements in minerals. Notable gemstones which contain beryllium include beryl (aquamarine, emerald) and chrysoberyl. The free element is a steel-gray, strong, lightweight brittle alkaline earth metal. It is primarily used as a hardening agent in alloys, notably beryllium copper.
The name beryllium comes from the Greek which means to "to become pale," in reference to the pale semiprecious gemstone beryl. Beryllium is a constituent of about 100 out of about 4000 known minerals and precious forms of beryl are aquamarine, bixbite and emerald.
Because of its low atomic number and very low absorption for X-rays, the oldest and still one of the most important applications of beryllium is in radiation windows for X-ray tubes. Also, due to its low atomic number, beryllium is almost transparent to energetic particles. Therefore it is used to build the beam pipe around the collision region in collider particle physics experiments. Notably all four main detector experiments at the Large Hadron Collider accelerator use a beryllium beam-pipe.
Beryllium has one of the highest melting points of the light metals. Because of its stiffness, light weight, and dimensional stability over a wide temperature range, beryllium metal is used for lightweight structural components in the defense and aerospace industries in high-speed aircraft, missiles, space vehicles and communication satellites. Several liquid-fuel rockets use nozzles of pure beryllium.
Commercial use of beryllium metal presents technical challenges due to the toxicity (especially by inhalation) of beryllium-containing dusts. Beryllium produces a direct corrosive effect to tissue, and can cause a chronic life-threatening allergic disease called berylliosis in susceptible persons.
Beryllium is a relatively rare element in both the Earth and the universe. The element is not known to be necessary or useful for either plant or animal life.
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