It occurs as a monomer, G-actin, a globular protein, and in living cells as a polymer, F-actin, which resembles two strings of beads twisted around each other into thin filaments.
以单体、球型肌动蛋白的形式出现，为一种球状蛋白质；在活体细胞内以聚合物、丝肌动蛋白的形式出现，像两串彼此缠绕拧成一条细丝的珠子。
youdao