If we examine the language describing toxic molecules more closely, we find that two overall terms are used – venoms and poisons. For example a black mamba is venomous while a poison dart frog is poisonous. To the untrained eye, it could appear that these two words describe the same thing, but what is actually the difference between venom and poison? An overview ccan be seen in Figure 1.
One of the main differences between ‘venom’ and ‘poison’ is how they are delivered into the victim’s body. ‘Poison’ can be delivered in several ways: it’s toxic both if eaten and if injected into the body. For this reason, ‘poison’ is often used to deter animals from eating the organism that makes the poison, like prey-animals or plants. ‘Poison’ often consists of small molecules that can easily cross from the stomach or intestine into the bloodstream, poisoning the animal and deterring it from eating the poisonous type of prey/plant again. Poisons are found in organisms such as poisonous plants, puffer fish, and poison dart frogs.
‘Venom’ is typically found in animals such as venomous snakes, scorpions, spiders and wasps. All of these animals have developed a special apparatus to deliver their venom quickly and efficiently. In snakes the delivery system is specialized fangs, while for scorpions and wasps it’s a stinger. ‘Venom’ is therefor not meant to be eaten and often consists of proteins that are far too large to cross the gastrointestinal tract into the body. Therefore, ‘venom’ is only toxic when it is injected into the body.
Another difference between ‘venom’ and ‘poison’ is that ‘venom’ is almost always made up of multiple toxins. In fact, some snakes venom actually contain more than 100 different toxins, underlining the complexity of certain venoms. In comparison, ‘poison’ typically consist of one or a few different toxins.
But how do you measure how toxic something is? We will dive in to that question in the following session.
Figure 1. Comparison of ‘poison’ and ‘venom’
