Why are CO and CN^– so toxic to humans?

Video transcript

All right. Hi, everyone. So this question is asking us which carbon compounds are toxic to humans in small amounts. Compound one is carbon dioxide compound two is carbon monoxide. Compound three is carbonate and compound four is cyanide. Option A says compounds two and three or one and three. Excuse me, option B says two and three. Option C says one and four and option D says two and four. So let's go through each of them individually starting off with carbon dioxide or CO2. Now recall that CO2 is one of the most important oxides of carbon found in our body. Matter of fact, recall, it is actually found in our body in relatively high amounts, right? Because when we inhale oxygen, what we end up exhaling is actually carbon dioxide. So because of this, it wouldn't make sense for carbon dioxide to be toxic to us in small amounts considering the fact that carbon dioxide is carried in our blood to our lungs before we actually exhale it. So carbon dioxide is not toxic in small amounts. However, the same cannot be said for carbon monoxide, which is co and to understand the reason why carbon monoxide is harmful to us. We have to recall an interesting protein called hemoglobin. Right, because hemoglobin is the protein in our blood. Specifically, our red blood cells that binds to oxygen and allows for its transport throughout our body. Now, what makes carbon monoxide so lethal to us is that carbon monoxide can actually bind to hemoglobin. And actually hemoglobin can bind to carbon monoxide stronger than it does to oxygen gas. So as a consequence of this right blood, specifically, our hemoglobin is less able to bind and therefore transport oxygen gas. Now this could have many severe consequences including death in the worst case scenario. So therefore, right, carbon monoxide is most certainly toxic to humans in small amounts. Now, carbonates on the other hand, or co 32 minus are essential to humans for a number of different reasons. Number one, they can be used to neutralize the acidity inside of our stomachs and also carbonates are part of the buffer system found in your blood because recall that a buffer system is put in place in order to resist drastic changes to the Ph, right. So, carbonate carbonates are in equilibrium with carbonic acid or H two co three to maintain the ph in your blood and prevent any drastic changes to it to the pie. So because carbonates are involved in multiple different processes inside of our bodies, it wouldn't make sense for carbonates to be toxic to us in small amounts. So last, but not least is cyanide or CN minus. No recall that CN minus is a very effective poison, right? Because cyanide can bind to an enzyme known as cytochrome oxides. And cytochrome oxidase plays a role in energy production specifically when it comes to the electron transport chain. So because cyanide interferes with our body's energy production. Even in very small doses, this leads to death as soon as our bodies cannot produce any more energy. So, cyanide is most definitely toxic to humans in small amounts to the point where it's actually lethal in small amounts. So therefore of the four compounds we discussed in this video compounds, two and four are toxic to humans in small amounts. That's carbon monoxide and cyanide. So our answer is going to be option d in the multiple choice. And with that being said, thank you so very much for watching and I hope you found this helpful.