Biology Biology Biology

1. Mutagens can be classified into Chemical mutagens and Physical mutagens. Isn't it ironic that there aren't any Biological mutagens when we're studying Bio and not Chem or Physics?

How mutagens cause mutations:
-The scammers called base analogs from some chemical mutagens. Like Maths, they both scam. That's why they have "log" functions in their names.
-Chemical mutagens like ethidium bromide insert themselves into DNA, distorting the double helix.
-Some change base pairing properties.
-Physical mutagens like X-rays and radiation PEWPEWPEWPEW can form thymine dimers.

2. We're also learning about uncontrolled cell division/cancer. Incidentally my star sign is Cancer. I'm allergic to crabs. Put two and two together. You get four!

Mr. Zheng, "No, actually you get 5 because JC is going to debunk everything you know about Chemistry except stoichiometry and the mole concept."

Ok...

What's the difference between proto-oncogenes and oncogenes?















One has a "-". Ok, just being random.

So either hyperactive or too many growth stimulating proteins, and then tumor suppressor genes get euthanised.

3. DNA Fingerprinting
-Non-coding sequences are used for DNA fingerprinting as they do not give any info about the person's biological state and health.

STRs vs VNTRs - compare length of each repeat, number of repeats, and how they can be analysed.

Obviously VNTRs are longer and bigger in every aspect, but their analysation speed is slower.

Compare Fat guy and Thin guy (or Shaotong v KaiTsi)
KaiTsi=STR
Shao=VNTR

KaiTsi is smaller but can run faster. Shao is bigger but runs slower. Get the pic? (All insults are apologised for and totally intentional)(jkjk)

4.PCR
Mastermix
Taq (Tak) Polymerase. To withstand heat of thermal cycle. Obtained from onsen bacteria. For extension of primers from a 5' to 3' direction.
Primers. Short sequences of complementary DNA nucleotides which anneal to the desired portion of the STRs.
Free nucleotides. A whole ton of them floating around the Mastermix, used to extend.
MgCl2 - or co-factor. Allows for Taq to perform optimally.
Buffer solution - For the muscles. Actually, no. It's for pH of DNA to be neutralised.

Denaturation - 94 C for 30 sec
Annealing - 52 C for 30 sec
Extension - 72 C for 1 min (extended period of time lololol)

OK whatever. Revision on comp ends here. Time to mug un-cyber style.