Amino Acid Sorting
Drag each amino acid into the category where it belongs. Keep in mind you don’t need to use every amino acid and they can be in more than one category.
Amino acid sorting exercise
0 placements
Amino acid pool — drag into any category below
1
Alpha-helical transmembrane domain of a receptor protein
Explanation
Alpha-helical transmembrane domains span the nonpolar region of the plasma membrane. Since like interacts with like, a transmembrane alpha-helix must contain hydrophobic residues. Proline is excluded because its cyclic structure would disrupt the alpha-helix.
2
Binding region of a protein that binds anionic & hydrophilic ligands
Explanation
Positively charged residues (R, K, H) attract negatively charged (anionic) ligands through electrostatic interactions, while polar residues (N, Q, S, T, Y, C) interact with hydrophilic ligands through polar interactions.
3
Potential target of protein kinase A
Explanation
Kinases, like protein kinase A or whatever one the MCAT decides to ask you about, phosphorylate serine, threonine, and tyrosine residues by adding a phosphate group to their hydroxyl (–OH) side chains.
4
Participate in the formation of salt bridges
Explanation
Salt bridges form between oppositely charged residues. The negatively charged side chains of aspartate (D) and glutamate (E) pair with the positively charged side chains of arginine (R), lysine (K), and histidine (H).