A mass spectrum has two peaks at 78 and 80 m/z with approximately a 3:1 ratio. Another set of peaks at 63 and 65 m/z is also observed with a 3:1 ratio. The largest peak has a molecular weight of 43. The last noted peak is at 27 m/z. Which structure best fits the MS data

Dying the folding patterns of protein molecules can microbiologists better understand cellular processes as well as some diseases, such as alzheimer’s, that are caused by proteins that have misfolded. the folding of these complicated molecules can be simulated on computers, but it takes a lot of processor power and time for even expensive supercomputers to do this. a group of researchers at stanford university developed software that can be used to distribute the processing of data to anyone who is willing to donate time on their idle personal computers. as a result, the researchers have been able to achieve protein-folding simulations that are far better than those other computing methods have done. which statement best describes the work of these researchers? the work is not scientific because the data are not processed in one location. the work is not scientific because the simulations are not reproducible. the researchers applied creativity to solve a problem in running an experiment. the researchers used only well-established scientific techniques.

A3.37-mg sample of protein was chemically digested to convert its nitrogen into ammonia and then diluted to 100.0 ml. then 10.0 ml of this solution was placed in a 50-ml volumetric flask and treated with 5 ml of phenol solution plus 2 ml of sodium hypochlorite solution. the sample was diluted to 50.0 ml, and the absorbance at 625 nm was measured in a 1.00-cm cuvette and found to be 0.486. for reference, a standard solution was prepared from 10.0 mg of nh4cl (molar mass = 53.49 grams/mole) dissolved in 1.00 l of water. then 10.0 ml of this standard was placed in a 50-ml volumetric flask, treated in the same manner as the unknown, and the absorbance found to be 0.323. finally, a reagent blank was prepared using distilled water in place of unknown, it was treated in the same manner as the unknown, and the absorbance found to be 0.076. calculate the weight percent of nitrogen in the protein.

Which statement is usually true about the relationship between activation energy and reaction rates? low activation energy barriers result in low rates. high activation energy barriers result in low rates. low activation energy barriers result in no reaction. high activation energy barriers result in no reaction.