@ 12:54 you say that Erwin Chargaff found the ratio of a/t c/g "across many different species of organism". Does that mean many as in every species tested, or many as in only some of the species tested?
8:37 You have the reaction, and result, wrong. The bond is formed between the 3' hydroxyl group of the top nucleotide, not the hydrogen of the 3' carbon. After the phosphodiester bond has formed, the 3' carbon of the top nucleotide should have a hydrogen remaining, but you show it having a hydroxyl group. And you show the carbon directly bonded to the phosphorus atom, but there is actually an oxygen atom between the carbon and the phosphorus.
26:37 It is not correct to say that the overall structure of a fully-functional protein is know as the quaternary structure. Many proteins are fully functional even though the have only a single polypeptide chain, so have a functional tertiary structure (and don't adopt a quaternary structure).
Great video, very informational, please add a place to donate money, I know these videos take alot of time to do. Keep up the good work double, I mean professor
Watson and Crick were in a race against the great two-time Nobel Prize winner Linus Pauling. Pauling thought that DNA had three strands, not two. We now know that when a cell divides, its DNA unwinds and the two strands separate from each other, and each strand goes into one of the "daughter cells." There are two daughter cells. Had Pauling been right, his triple-stranded DNA would have produced three daughter cells. Clearly, Pauling did not realize the connection between the number of strands and the number of daughter cells, and therefore did not realize that DNA replicates by separating the two strands. By the way, in organisms that have two parents, there are two chromosomes. In a sci-fi universe with three sexes, each cell would have three chromosomes. So there's one chromosome (one copy of the complete DNA molecule) for each parent, and one strand (one component of the DNA molecule) for each daughter cell. It took me a long time to figure this out. I wonder how Pauling thought the A-T and G-C pairing could have played into his three-strand model. Does not this pairing speak clearly of two strands? Apparently not.
Drishty Kamboj so that protein can understand it. Because DNA and Proteins are in different “languages” and the ribosome translates the DNA language so Proteins can understand.
21:36 Sickle-cell anemia is not advantageous. You are confusing a disease condition for an allele. Sickle cell anemia is a disease in people who are homozygous for the sickle cell allele: humans have 2 copies of the gene, and homozygotes have both of their versions as the mutated, sickle cell allele. That is not advantageous. A heterozygous person has one sickle cell allele and one "normal" allele: such people do not have the disease sickle cell anemia. They are carriers for the disease, but they don't have it. In regions where malaria is prevalent. 1) Being homozygous for the sickle cell allele would mean having the disease sickle cell anemia, which is bad. 2) Being homozygous for the "normal" allele means the person has none of the protection against malaria that the sickle cell allele provides, which is also bad for the person. 3) Being heterozygous provides the best of both worlds: the person does not have the disease sickle cell anemia, and does get some protection against malaria. This is the classic example of heterozygote advantage.
