They're stuck to a surface that's provided by the environment that's around them, they're not swimming free in solution.

他们黏联在,周围环境的表面上,而不会在溶液中自由运动

耶鲁公开课 - 生物医学工程探索课程节选

They also allow their populations of proteins on the surface of each cell that allow it to interact with its environment, they're receptors and cell adhesion receptors like I talked about last time.

它们同时也使得,这些细胞表面的蛋白质群,使得细胞能够和周围环境进行互动,它们是受体和细胞粘附受体,我上次也说过的

耶鲁公开课 - 生物医学工程探索课程节选