Upload an image of your answers to this question. Draw the structure of the N-terminal residue at pH 12.0.  (2 pts) Draw the structure of the C-terminal residue at pH 1.0 ?  (2 pts.) Draw the principle structure of residue number  2 at pH 5 showing the absolute stereochemical configuration of the L family of amino acids. (3 pts.)

In the procedure above, they mentioned that the purified protein was alkylated. Briefly explain why it might be desirable to treat the reduced protein with iodoacetic acid (ICH2CO2H) before it is subjected to further purification by HPLC. 

Upload an image of your answers to this question. Splenda is a sugar substitute that can be used in cooking, whereas Nutrasweet cannot (It is a dipeptide and is thermally unstable). Splenda is made from D-sucrose by substitution of some of the hydroxyl groups with chlorine atoms. Draw the structure of Splenda given the following information about the hydroxyl groups that have been replaced by chlorine atoms. The hydroxyl groups at carbons 1 and 6 of the sugar in the furanose form and the hydroxyl group at carbon 4 of the sugar in the pyranose form have been replaced by chlorine atoms. The sugar in the pyranose form has the same stereochemical configuration as galactose.   For your interest: A foreign post-doctoral student in Great Britain first prepared Splenda. He misunderstood the word “test” and thought the supervisor said “taste,” so he did (not good chemical practice).  It turned out that this chlorinated derivative of sucrose is 600 times sweeter than sucrose itself.

Based on your understanding of the regulation of negative repressible operons in bacteria,  what would you expect to occur if the regulator protein contained a mutation that made it nonfunctional? 

This figure shows the results of a two-dimensional gel that was run to separate the proteins found in a snake toxin. Locate the prominent dark spot in the upper right-hand quadrant on the two-dimensional gel and answer these questions.  Name one thing that you can infer about the amino acid composition of this major spot from the isoelectric focusing direction of the gel?  What is one thing that you can infer from the PAGE direction of this gel about this protein? Image Source: Hatakeyama, D. M., de Morais-Zani, K., Serino-Silva, C., Grego, K. F., Sant’Anna, S. S., Fernandes, W., Aniz, P. A. E. A., Torquato, R. J. S., Tanaka, A. S., Sanz, L., Calvete, J. J., & Tanaka-Azevedo, A. M. (2018). Examination of biochemical and biological activities of Bothrops jararaca (Serpentes: Viperidae; Wied-Neuwied 1824) snake venom after up to 54 years of storage. Toxicon (141), 34–42. Image Description  A two-dimensional Electrophoresis (2-DE) gel showing the separation of proteins. The x-axis represents the pH range from 3 to 10, and the y-axis represents molecular weight from 15 kDa to 250 kDa. Multiple protein spots are visible, indicating their isoelectric points and molecular weights. The label A marks a significant area of interest on the gel. The gradient shading reflects the concentration of proteins, with darker spots representing higher protein abundance.

What can you directly conclude from these results?

C. The scientist identifies a Pribnow box in the molecule. What type of molecule is she examining?

Which of the following sequences best represents the beginning of the mRNA molecule that will be transcribed from this sequence?

Which type of chromosome mutations: Decrease the amount of genetic material in a particular chromosome?  [option1] Increase the amount of genetic material in a particular chromosome? [option2] Increase the amount of chromosomes in a cell?  [option3] Change the position of DNA sequences in a single chromosome without changing the amount of genetic material?  [option4]    

The following four questions (A-D)  are based on the scenario below: A scientist has isolated a molecule of nucleic acid but is unsure whether it is DNA or RNA. She investigates the features present in the molecule to determine its identity. A. The scientist observes that the molecule contains both a promoter and a terminator. What type of molecule is she examining?