What is the isoelectric point, pl, for the pentapeptide, MGHFD 4.8 3.1 Show work O 7.8 2.3 O 9.5

Suppose a chloride ion and a sodium ion are separated by a center–center distance of 5 Å. Is the interaction energy (the energy required to pull them infinitely far apart) predicted to be larger if the medium between them is water, or if it is n-pentane? If Ca 2+, Na+, and F - each have ionic radii ∙1.16. Which ionic bond is stronger: Ca-F or Na-F? If Ca 2+ is often bound on the surface of a protein by carboxylic acid functional groups. If the pKa of a particular ¬COOH group is 4.2, would you predict Ca 2+ to be most tightly bound at pH 8, pH 4.2, or pH 3? Explain your answer.

Calculate the lattice enthalpy for RbC1. You will need the following information: Species AfH°, kJ/mol Rb(g) RbCl(s) Cl(g) 80.9 - 435.4 121.3 Enthalpy of ionization for Rb(g) is 403.0 kJ/mol; electron attachment enthalpy for Cl(g) is −349.0 kJ/mol. Lattice enthalpy = kJ/mol

A chemist, during the course of an analysis, runs across a chemical composed of carbon, hydrogen, and oxygen in the proportion 1:2:1 and having a six-sided molecular shape. It is probably (a) a pentose, (b) an amino acid, (c) a fatty acid, (d) a monosaccharide, (e) a nucleic acid.