Can someone please help me fully understand this question? The correct answer will be upvoted!

The ionic status of amino acids influences the native conformation (3D structures) of proteins. The net charge of proteins is dependent on the ionic states of ionizable groups in the side chain (R-group) of amino acid residues. Each ionizable group is associated with a specific pKa value. For example, pKa value of carboxyl-, amino-, and R- group of tyrosine is 2.2, 9.2, and 10.5, respectively. a) Draw the four ionic forms of glutamate and indicate at what pH, do the changes of the ionic forms could occur. Also, indicate the net charge of each four ionic forms. b) Which ionic form of glutamate can behave as the "zwitterion"? c) What is the isoelectric pH of glutamate? Show the calculation. d) At the physiological pH of 7.4, what type of a non-covalent bond could the R-group of glutamate form with the R-group of lysine? Use a diagram to demonstrate the above interaction