| Symbol: Cs; atomic weight: 132.905; atomic number: 55 |
| Symbol: Es; atomic weight: 254; atomic number: 99 |
antimetabolite an·ti·me·tab·o·lite (ān'tē-mĭ-tāb'ə-līt', ān'tī-)
n.
A substance that closely resembles an essential metabolite and competes with, interferes with, or replaces the metabolite in physiological reactions.