The R-groups give the amino acids their physical-chemical characteristics such as polarity (hydrophobic or hydrophilic) and charge (acidic or positive versus basic or negative).
R基团赋予氨基酸物理化学特性，例如极性（亲水性和疏水性）以及电荷（酸性或正电荷，碱性或负电荷）。
2
Its polarity and electrical conductivity make it an ideal solvent for conducting the chemical reactions that are the basis of metabolism.
水的极性和导电性，使它成为新陈代谢的基本化学反应的理想溶剂。
3
Its improvement range depends on the polarity and chemical structure of the coupling agents.