Wednesday, August 31, 2011

Small and large molecules in cells.

There are four major macromolecules in cells which include fats/lipids, polysaccharides, nucleic acids and proteins.

Fats/lipids are consisted of fatty acids and their derivatives. Fatty acids can be a storage of energy in terms of triacylglycerol which consists of three fatty acid molecules and one glycerol molecule. Also, glycolipids and phospholipids can be produced by replacing one fatty acid in triacylglycerols with sugar or phosphorate group. Fatty acids are not only the energy storage but also the major components in cell membranes.

Sugars can serve as energy source, structural components and signal transducer. There are a lot of types of sugars which can be used as energy source such as mono-saccharide glucose, disaccharide sucrose and  polysaccharides starch and glycogen. It can also serve as back bones for DNA and RNA as well as functioning in signal recognition on the membrane surface as glycolipid.





How particles interact with each other?

Because most organisms consist of cells, let us talk about it in the cytoplasm, that is, in water. Generally, there are two types of bonds between atoms to make particles bigger: covalent and non-covalent bonds.

Covalent bonds means two atoms share electrons rather than transfer from one to another. After it reaches a stable condition, the distance between two atoms is called bond length. If one atom has a stronger ability to pull electrons toward itself, there will be a negative pole at its end while the other end will be a positive pole. The result is, they make a polar molecule with a dipole.

Non-covalent bonds include four types. Electrostatic attraction, which happens between two permanent polar atoms. Hydrogen bond, which means hydrogen atom is shared by two atoms with negative charge. Both of the above are weakened in water because they are surrounded by water molecules. The third is van der waals attraction which results from the simultaneous attraction between two non-polar molecules. At last, it comes to the hydrophobic repulsion. Water molecules will repulse hydrophobic molecules together so as to form some weak bonds, though it cannot be called bonds actually.

Sunday, August 28, 2011

Bed bugs (4)

Tips:
1. If you are not sure whether your clothes, comforter, pillows or whatever are infected by bed bugs or not, pack them and put them into your trunk - the heat in Oklahoma will make them DIE and this is FREE!
2. After throw your mattress sets (unfortunately most of those who found bugs have to throw them away), do not buy new ones until bugs are cleaned up. Give yourself at least a buffering week to find out whether they are completely out because their larvae and pupae might still exist. During that period, sleep on an air mattress because you can easily carry it everywhere and the most important is that it can be sterilized in your trunk!
3. Wash and dry your clothes with DRIER as often as possible. Drier also works good at killing bugs and their progeny.
4. Make good covers for your mattress, pillow, comforter and so on. You do not have to wash everything to get rid of bugs but to wash covers.
5. Do not use Coleman air mattress. They suck. Leaking.


Bed bugs (3)

3. What to do if your home has bed bugs?
First, find out the source of those bugs and cut further infection. Usually, they can travel between places through used furniture, suitcases and trash. For example, I check with my previous roommates and one of them said they were bitten by something and found bugs in his used furniture several months ago. After he threw it away, it became much better. Obviously, bugs traveled into our apartment through used furniture. Because my previous roommate has moved out, I do not have to worry about the source any more. What I need to do is to clean bugs up and I will be done. For my new roommate, all his furniture is new so I do not have to take any actions on that.
Second, identify bugs which bite you. Usually beg bugs hide at the edge of your mattress, corners of your carpet, and even in your pillow and comforter. Find them out. They are almost square-shaped, extremely flat, and brown in color.
Third, throw your furniture which got infected, IMMEDIATELY.
At last, call professionals to exterminate them.

Bed bugs (2)

2.How to diagnose by yourself you are bitten by bed bugs or something else?
Usually what we need to do is to distinguish the bite of bed bugs from those from mosquitoes. If you are bitten by a mosquito, there will be a single blotch and it won't be itchy after one day, in most cases. However, if you are bitten by a bed bug, it will be very different: The number of blotches will vary from three to six or seven, but definitely more than one. Also, it will be annoying you for two or three days. Those blotches will get together into clusters or align into a straight line but the size will be generally the same as a bite by a mosquito. To sum up, we can judge we are experiencing bed bugs or mosquitoes with two standards, the number and the pattern of those bites. Bed bugs make clusters or a line of bites while mosquitoes make only one each time.

Bed bugs (1)

If unfortunately you are being annoyed by them, here is some my personal experience about how to fight against bed bugs!

Background: I had a new roommate recently since August 1st and my previous roommate just moved out before that. I had been experiencing itch since the end of July for at least one week. However, now I am fine about the bugs after about a one-month campaign and would like to share some experience and information.

1. Bed bugs once occupied a lot of apartments and houses since 1930s just as our 'friends'. They were a problem all over the world because they are extremely resistant to starvation and have a great ability to reproduce once the environment allows. You can find them from slums to five-star hotels. After the application of DDT, an amazingly effective insecticide, they are almost driven out of our rooms. Nowadays, DDT is not a chemical regarded as safe enough and the ban on DDT definitely helped bugs' coming back.

Tuesday, August 23, 2011

I cannot find a parking lot!

G! I have a staff permit but one hour driving is not sufficient for me to find a parking lot! Are we recruiting new people?