Glutamic acid and Lycine: Hydrogen bonding could occur between the NH3+ group of Lysine and the COO- group of Glutamic acid; and Van der Waals (nonpolar-nonpolar) forces/interactions could arise between the nonpolar methylene groups of both R groups. Phenylalanine and Isoleucine: Phenylalanine is quite hydrophobic so it works in hydrophobic reactions. Both have nonpolar R groups so the only interactions they could undergo would be the weakly attractive Van der Waals forces between the methylene groups of both R groups. However, Phenylalanine is an aromatic compound with an aromatic ring, which is capable of undergoing noncovalent Pi-system interactions but not with Isoleucine because it is not polar enough to distort the Pi system of the aromatic ring. Solution Glutamic acid and Lycine: Hydrogen bonding could occur between the NH3+ group of Lysine and the COO- group of Glutamic acid; and Van der Waals (nonpolar-nonpolar) forces/interactions could arise between the nonpolar methylene groups of both R groups. Phenylalanine and Isoleucine: Phenylalanine is quite hydrophobic so it works in hydrophobic reactions. Both have nonpolar R groups so the only interactions they could undergo would be the weakly attractive Van der Waals forces between the methylene groups of both R groups. However, Phenylalanine is an aromatic compound with an aromatic ring, which is capable of undergoing noncovalent Pi-system interactions but not with Isoleucine because it is not polar enough to distort the Pi system of the aromatic ring..

1. Glutamic acid and Lycine: Hydrogen bonding could occur between the NH3+
group of Lysine and the COO- group of Glutamic acid; and Van der Waals (nonpolar-nonpolar)
forces/interactions could arise between the nonpolar methylene groups of both R groups.
Phenylalanine and Isoleucine: Phenylalanine is quite hydrophobic so it works in hydrophobic
reactions. Both have nonpolar R groups so the only interactions they could undergo would be the
weakly attractive Van der Waals forces between the methylene groups of both R groups.
However, Phenylalanine is an aromatic compound with an aromatic ring, which is capable of
undergoing noncovalent Pi-system interactions but not with Isoleucine because it is not polar
enough to distort the Pi system of the aromatic ring.
Solution
Glutamic acid and Lycine: Hydrogen bonding could occur between the NH3+
group of Lysine and the COO- group of Glutamic acid; and Van der Waals (nonpolar-nonpolar)
forces/interactions could arise between the nonpolar methylene groups of both R groups.
Phenylalanine and Isoleucine: Phenylalanine is quite hydrophobic so it works in hydrophobic
reactions. Both have nonpolar R groups so the only interactions they could undergo would be the
weakly attractive Van der Waals forces between the methylene groups of both R groups.
However, Phenylalanine is an aromatic compound with an aromatic ring, which is capable of
undergoing noncovalent Pi-system interactions but not with Isoleucine because it is not polar
enough to distort the Pi system of the aromatic ring.