Insulin acts like the key, fitting into the lock on the cell to open the door for glucose to get into the cell so it can be turned into energy.

胰岛素就像一把钥匙，把细胞表面的锁（受体）打开后，葡萄糖于是进入细胞，被转化成能量。

Each of the oodles of odor molecules that you are capable of detecting fits into a specific smell sensory receptor, just like a key fits in a lock.

你能够检测到的每一种气味分子都适合特定的气味感受器，就像钥匙适合锁一样。