The amino acid Prolinehas a pk1 of 1.99, pk2 of 10.60. The amino acid Serine has pk1 of 2.21 and a of pk2 of 9.15. If these two amino acids bind together by peptide bond creating the peptide sequence Pro-Ser . What will be the overall charge of this peptide at the physiological pH of 7? a) overall charge will be neutral

b) overall charge will be neutral on Pro and negatively charged on the Ser

c) overall charge will be negative

d) overall charge will be positive due to the presence of the peptide bond

Consider three unlabeled bottles, each contain small pieces of one of the following metals. - magnesium - sodium - silver the following reagents are used for identifying the metals. - pure water - a solution of 1.0 molar hcl - a solution of concentrated hno3 (a) which metal can be easily identified because it is much softer than the other two? describe a chemical test that distinguishes this metal from the other two, using only one of the reagents above. write a balanced chemical equation for the reaction that occurs. (b) one of the other two metals reacts readily with the hcl solution. identify the metal and write the balanced chemical equation for the reaction that occurs when this metal is added to the hcl solution. use the table of standard reduction potentials (attached) to account for the fact that this metal reacts with hcl while the other does not. (c) the one remaining metal reacts with the concentrated hno3 solution. write a balanced chemical equation for the reaction that occurs. (d) the solution obtained in (c) is diluted and a few drops of 1 m hcl is added. describe what would be observed. write a balanced chemical equation for the reaction that occurs.

Use the drop-down menus to answer each question. which runner finished the 100 m race in the least amount of time? which runner stopped running for a few seconds during the race? at what distance did anastasia overtake chloe in the race?

What is the molar mass of ca(cio4)2