Thursday, April 10, 2008
Thurs-Day 1
Bio- HW: Outlines 13.2 and 13.3 are due by TUESDAY, due to the change in the exam date (which is now on next TUESDAY.)
we discussed some more methods involving BIOTECHNOLOGY. Specifically, we saw how gel electrophoresis is used to separate various sized fragments of DNA that were cut by various restriction enzymes. Because all humans have at least some differences in their base sequences that make up the genes of their chromosomes, restriction enzymes, which cut the DNA at specific base sequence sites, will cut the DNA from different people into different sized fragments. These fragments are loaded/injected into a gel that is hooked up to a battery. The negatively charged DNA fragments travel from the negative electrode of the battery through the gel towards the positive electrode of the battery. The larger fragments travel slowly while the smaller fragments travel more rapidly. When the bands have clearly separated, the resulting banding pattern is like a DNA fingerprint that is used to identify or to rule out individuals as the source of the DNA sample.
Chem 7- we discussed the mechanism for the rule, "LIKE DISSOLVES LIKE". That is, POLAR molecules can dissolve other polar molecules but polar molecules do NOT significantly dissolve NONPOLAR molecules because the polar molecules are more attracted to themselves than they are attracted to the nonpolar molecules. This phenomenon is all caused by the ATTRACTION of the partially charged regions (poles) of the polar molecules to the oppositely charged polar regions of other molecules (or to FULLY oppositely charged ions).
We went through each possible type of homogeneous mixture/solution and we discussed the "Tyndall test" to see whether an aqueous mixture is a TRUE (CLEAR) solution.
Chem 8/9- we discussed the mechanism for the rule, "LIKE DISSOLVES LIKE". That is, POLAR molecules can dissolve other polar molecules but polar molecules do NOT significantly dissolve NONPOLAR molecules because the polar molecules are more attracted to themselves than they are attracted to the nonpolar molecules. This phenomenon is all caused by the ATTRACTION of the partially charged regions (poles) of the polar molecules to the oppositely charged polar regions of other molecules (or to FULLY oppositely charged ions).
We went through each possible type of homogeneous mixture/solution and we discussed the "Tyndall test" to see whether an aqueous mixture is a TRUE (CLEAR) solution.
We then deciphered Table F, which lists the ions of soluble salts and or insoluble (precipitate forming) salts. This Table is useful in predicting whether a double replacement ionic reaction will occur and go to "completion".
we discussed some more methods involving BIOTECHNOLOGY. Specifically, we saw how gel electrophoresis is used to separate various sized fragments of DNA that were cut by various restriction enzymes. Because all humans have at least some differences in their base sequences that make up the genes of their chromosomes, restriction enzymes, which cut the DNA at specific base sequence sites, will cut the DNA from different people into different sized fragments. These fragments are loaded/injected into a gel that is hooked up to a battery. The negatively charged DNA fragments travel from the negative electrode of the battery through the gel towards the positive electrode of the battery. The larger fragments travel slowly while the smaller fragments travel more rapidly. When the bands have clearly separated, the resulting banding pattern is like a DNA fingerprint that is used to identify or to rule out individuals as the source of the DNA sample.
Chem 7- we discussed the mechanism for the rule, "LIKE DISSOLVES LIKE". That is, POLAR molecules can dissolve other polar molecules but polar molecules do NOT significantly dissolve NONPOLAR molecules because the polar molecules are more attracted to themselves than they are attracted to the nonpolar molecules. This phenomenon is all caused by the ATTRACTION of the partially charged regions (poles) of the polar molecules to the oppositely charged polar regions of other molecules (or to FULLY oppositely charged ions).
We went through each possible type of homogeneous mixture/solution and we discussed the "Tyndall test" to see whether an aqueous mixture is a TRUE (CLEAR) solution.
Chem 8/9- we discussed the mechanism for the rule, "LIKE DISSOLVES LIKE". That is, POLAR molecules can dissolve other polar molecules but polar molecules do NOT significantly dissolve NONPOLAR molecules because the polar molecules are more attracted to themselves than they are attracted to the nonpolar molecules. This phenomenon is all caused by the ATTRACTION of the partially charged regions (poles) of the polar molecules to the oppositely charged polar regions of other molecules (or to FULLY oppositely charged ions).
We went through each possible type of homogeneous mixture/solution and we discussed the "Tyndall test" to see whether an aqueous mixture is a TRUE (CLEAR) solution.
We then deciphered Table F, which lists the ions of soluble salts and or insoluble (precipitate forming) salts. This Table is useful in predicting whether a double replacement ionic reaction will occur and go to "completion".
# posted by C @ 6:56 PM 
