For my Jing project, I decided to cover nucleic acids. Below is the presentation that I came up with. (Sorry about the varied volumes as well as the background noises)
Thursday, September 30, 2010
Wednesday, September 22, 2010
Properties of Water
Properties of Water:
Water is commonly referred to around the world as the universal solvent because so many substances dissolve in it. Since it is very common to find things that dissolve in water, it was given this moniker. Water also is adhesive and cohesive. The adhesive nature of water refers to water's ability to stick to other substances, while the cohesion refers to water's trait of sticking with other water. As a result of cohesion, you obtain surface tension, which refers to the surface of water where the hydrogen bonds need to be severed in order for something to pass through them. This was evident during the paperclip experiment (see picture above) as well as when a person does a belly flop in to a pool. As a result of adhesion, you arrive at capillary action, which refers to when water climbs up the sides of objects such as straws, creating a meniscus. Water is polar, which means that one side of the molecule has a slightly positive charge while the other has a charge that is slightly negative. When multiple water molecules are introduced to each other, the positive side is attracted to the negative side, resulting in a hydrogen bond, which is fairly weak when singular, but strong when in the masses. Water is well known to have a density of 1g/mL as a liquid. Most substances are denser as solids and less dense as liquids, but water breaks this rule. Ice is less dense than water because of the way the hydrogen bonds act when they freeze. While most solids pack more molecules in a smaller space, the water molecules spread out more when frozen, and subsequently lead to a smaller density. (Video is simulation of freezing water) This spread out molecular format is known as a lattice formation. If water did not behave like this, then ice would sink, there would be no more icebergs, and ponds would begin to freeze from the bottom and work its way up. Another property of water is its specific heat. This refers to the amount of energy that is needed to raise one gram of a substance (in this case water) by one degree Celsius. Water has a very high specific heat, which explains why on a hot summers day the water in the ocean stays cool. This is important in nature because it helps prevent the body temperatures of mammals from increasing greatly due to the weather. The final property that I believe water has is amphoterism, or the fact that pure water is a neutral seven on the pH scale, but that it can easily be manipulated to become more acidic or basic depending on what it needs to be used for. It should be noted that the pH scale is a logrithmic scale, which means that for every increase in one on the 0-14 scale, the liquid is becoming more basic by ten times the previous number.
These are what I believe to be the properties of water that make it such a unique compound.
Sources:
http://en.wikipedia.org/wiki/Amphoteric
http://www.uni.edu/~iowawet/H2OProperties.html
http://prezi.com/uod1timpjiwk/8-properties-of-water/
http://www.youtube.com/watch?v=gmjLXrMaFTg
BSCS Biology a Molecular Approach: Ninth Edition
- Universal Solvent
- Adhesion and Cohesion
- Polarity
- Density/Lattice Formation of Ice
- Capillary Action
- Surface Tension
- Specific Heat
- Amphoterism/Neutrality
Water is commonly referred to around the world as the universal solvent because so many substances dissolve in it. Since it is very common to find things that dissolve in water, it was given this moniker. Water also is adhesive and cohesive. The adhesive nature of water refers to water's ability to stick to other substances, while the cohesion refers to water's trait of sticking with other water. As a result of cohesion, you obtain surface tension, which refers to the surface of water where the hydrogen bonds need to be severed in order for something to pass through them. This was evident during the paperclip experiment (see picture above) as well as when a person does a belly flop in to a pool. As a result of adhesion, you arrive at capillary action, which refers to when water climbs up the sides of objects such as straws, creating a meniscus. Water is polar, which means that one side of the molecule has a slightly positive charge while the other has a charge that is slightly negative. When multiple water molecules are introduced to each other, the positive side is attracted to the negative side, resulting in a hydrogen bond, which is fairly weak when singular, but strong when in the masses. Water is well known to have a density of 1g/mL as a liquid. Most substances are denser as solids and less dense as liquids, but water breaks this rule. Ice is less dense than water because of the way the hydrogen bonds act when they freeze. While most solids pack more molecules in a smaller space, the water molecules spread out more when frozen, and subsequently lead to a smaller density. (Video is simulation of freezing water) This spread out molecular format is known as a lattice formation. If water did not behave like this, then ice would sink, there would be no more icebergs, and ponds would begin to freeze from the bottom and work its way up. Another property of water is its specific heat. This refers to the amount of energy that is needed to raise one gram of a substance (in this case water) by one degree Celsius. Water has a very high specific heat, which explains why on a hot summers day the water in the ocean stays cool. This is important in nature because it helps prevent the body temperatures of mammals from increasing greatly due to the weather. The final property that I believe water has is amphoterism, or the fact that pure water is a neutral seven on the pH scale, but that it can easily be manipulated to become more acidic or basic depending on what it needs to be used for. It should be noted that the pH scale is a logrithmic scale, which means that for every increase in one on the 0-14 scale, the liquid is becoming more basic by ten times the previous number. These are what I believe to be the properties of water that make it such a unique compound.
Sources:
http://en.wikipedia.org/wiki/Amphoteric
http://www.uni.edu/~iowawet/H2OProperties.html
http://prezi.com/uod1timpjiwk/8-properties-of-water/
http://www.youtube.com/watch?v=gmjLXrMaFTg
BSCS Biology a Molecular Approach: Ninth Edition
Saturday, September 11, 2010
Prologue and Course Description Response
After reading the prologue of our textbook and the course expectations sheet, I have drawn several conclusions of what I wish to achieve this year. The prologue gave brief descriptions of what would be covered in the textbook, and included topics such as evolution, bioethics, and many others. I hope that the textbook will inform and educate me about how the body works, how cells work, how animals bodies developed over time through natural selection, and how medicine can be abused. The prologue also explained hypotheses and predictions, as well as pseudoscience. I look forward to achieving a much greater understanding of all these topics. Through the course expectations sheet, I hope that this year I learn to become a more independent learner by formulating my own hypothesis and coming to my own conclusions while improving my clarity in labs and projects. Overall, I think this year has a lot to offer academically.
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