BabcockHall

That looks fine to me.

That's better. The third from the last structure is a six-membered ring with a positive charge, and there is no reason to draw it looking so distorted. I don't understand what is happening between the third-from-last and the second to last structure. Finally, a base (which could be water) is needed to accept a proton to form the alkene product. The water molecule you drew is doing something that I do not understand.

When the electrons of the sigma bond leave the carbon atoms, that carbon atom should have a formal positive charge, which I do not see in your drawing.

I suggest drawing the first carbocation in the reaction and asking what kind of carbocation it is (primary, secondary, or tertiary). Carbocation rearrangements occur when an electron pair from a sigma bond moves to form a different bond. They are often seen when they lead to a carbocation of greater stability in the product than in the reactant.

Have you learned anything about how carbocations can rearrange?

Alcohol may be oxidized to acetyl CoA, but pyruvate is not on this pathway. Also, coenzymes such as thiamine are not consumed in enzymatic reactions.

I looked into this subject briefly a few years ago, and I was not entirely convinced that the reasons were fully understood. However, I found out that decreased overall consumption of food, blocking of absorption of thiamine, or other factors might be responsible for the deficiency in thiamine. http://pubs.niaaa.nih.gov/publications/arh27-2/134-142.htm

Your reference also notes that some organic acidemias are associated with hypoketotic hyperglycemia. I am not surprised that difference metabolic defects show a variety of outputs.

@OP, Please show your work in opening post in the future.

Although CharonY paints a relatively negative picture, I cannot say that these concerns are not real. Some biochemistry research is done in biotechnology companies, but there are constraints.

Some graduate programs in biochemistry tend to emphasize enzymology more than others. For example Brandeis University used to, but I don't know whether or not they still do. Enzymology can be applied to a number of different problems in academic research or in industry.

For what compound is ALD the abbreviation, and what sources of information have you used so far?

I am not an expert, but I would like to ask for some clarification. When you say RT-PCR, do you mean real-time PCR or do you mean reverse transcriptase PCR?

Can you define lactone and ester for us?

Protein synthesis appears to be a compromise between speed and fidelity. There is at least one ribosomal mutation that makes the process slower but more accurate. EDT My comment about substrates in a previous message might mislead the unwary. All enzymes can reject a incorrect (non cognate) substrate via dissociation, but only a few enzymes proofread, and kinetic proofreading is a subset of all proofreading mechanisms.

Yes, they happen at the ribosome. I don't see why there would necessarily be twenty attempts. I don't look upon it any differently than I look upon an enzyme's choosing the correct substrate. In this case the enzyme is the ribosome and the substrate is the aminoacyl tRNA.

The process of choosing the correct codon/anticodon pair proceeds by two steps. The first step is recognition, and some non cognate tRNA molecules are rejected at this point. Then Ef-Tu hydrolyzes GTP, and additional non cognate tRNAs are rejected at this proofreading step. The process is called kinetic proofreading.

"So in DNA replication the polymerases need to synthesize in opposite directions from the replication fork and one strand is called the leading strand and the other is called the lagging strand and that they are chosen arbitrarily?" Assuming that we are talking about E. coli, there are two replication forks that move in opposite directions. Each one has two copies of DNA polymerase III, but there are different accessory proteins. The synthesis of the leading strand is continuous, and it is much simpler and requires fewer proteins. The synthesis of the lagging strand is not continuous, and so is more complex.

"A pulse oximeter uses light to measure the oxygen saturation level, the percentage of hemoglobin in your red blood cells carrying oxygen. Normal oxygen saturation levels fall between 95 and 99 percent." From http://www.livestrong.com/article/124374-normal-range-blood-oxygen-level/ This is about what I would have expected. When blood passes through resting muscle, the hemoglobin saturation level drops considerably, but IIUC not to anywhere near zero. This leads to an interesting question, which is how such a device is able to focus on arterial blood, which should be richer in oxygen than venous blood. " Pulse oximetry technology utilizes the light absorptive characteristics of hemoglobin and the pulsating nature of blood flow in the arteries to aid in determining the oxygenation status in the body. First, there is a color difference between arterial hemoglobin saturated with oxygen, which is bright red, and venous hemoglobin without oxygen, which is darker." http://www.hopkinsmedicine.org/healthlibrary/test_procedures/pulmonary/oximetry_92,P07754/ So far I have just skimmed this site, but there appears to be some good information: http://www.howequipmentworks.com/pulse_oximeter/

Somewhat of a tangent, but "Why Nature Chose Phosphate" an article by Frank Westheimer, an important bioorganic chemist, about 1987 is worth one's time. "Why nature chose phosphate to modify proteins" by Tony Hunter from 2013 is good, also.

I am not sure. However, you are probably already aware that EF-G resembles a charged tRNA molecule.

The peak is too narrow to be OH. C-H sp3 is less than 3000 wave numbers; C-H sp2 is > 3000 wave numbers. The peaks near 1750 and 1200 are the only other ones that are helpful here. The smell is also useful.

There are only two human pathways that need vitamin B12. However, there is a rare metabolic disease that is a hereditary deficiency in one of them. A woman almost got put away for life for poisoning her son because it was improperly diagnosed. Some but not all ribonucleotide reductases are B12-dependent. The coenzyme related to niacin is present in so many pathways that it is difficult to single one out.

Just to be clear, is your assignment to write about the biosynthetic pathways to form these two coenzymes, or is it to write about which biosynthetic pathways in which these coenzymes participate? Many biochemistry textbooks have a discussion of how the coenzymes are formed. The relationship of maize (corn) to pellagra ties in with tryptophan branch of your pathway: http://www.ncbi.nlm.nih.gov/pubmed/6357846

It is generally bad to heat a closed system. Could you have a drying tube present? Could you use a Firestone valve?