Theoretically, a protein could assume a virtually infinite number of configurations and conformations. Which of the following features of proteins drastically limit the actual. number of available conformations and configurations? (Select all that apply.) Only L-annino acids (except for glycine) are used in proteins, The peptide group is planar, with only cis and trans confornations possible. The ability of a protein to rearrange its geometry is dramatically limited by the interactions of polar and charged amino acids with water. The Ramachandran angles and are limited in their values due to steric restrictions. Although any one of 20 amino acids is possible at each position, only one is used. - 9 ltem attempits remaining