A 由C<img border="0" alt="" src="https://img.weimei168.com/uploads/upimg/20230804/12258331_0.gif">和C-COOH组成 B
由C<img border="0" alt="" src="https://img.weimei168.com/uploads/upimg/20230804/12258331_0_1.gif">和C<img border="0" alt="" src="https://img.weimei168.com/uploads/upimg/20230804/12258331_0_2.gif">组成 C
由C<img border="0" alt="" src="https://img.weimei168.com/uploads/upimg/20230804/12258331_0_3.gif">和N组成 D
肽键有一定程度双键性质 E
肽键可以自由旋转