1
00:00:00,560 --> 00:00:03,840
Speaker 1: Welcome to Brainstuff from house stuff Works dot com where

2
00:00:03,880 --> 00:00:15,600
Speaker 1: smart happens. Hi, I'm Marshall Brain with today's question, why

3
00:00:15,760 --> 00:00:20,400
Speaker 1: is carbon monoxide so poisonous? Every poison has a particular

4
00:00:20,480 --> 00:00:23,720
Speaker 1: trait that causes it to be poisonous. In the case

5
00:00:23,720 --> 00:00:27,160
Speaker 1: of carbon monoxide, the trait has to do with hemoglobin

6
00:00:27,240 --> 00:00:30,880
Speaker 1: in your blood. Hemoglobin is made up of proteins that

7
00:00:31,040 --> 00:00:35,400
Speaker 1: bind iron atoms. The structure of hemoglobin causes oxygen to

8
00:00:35,440 --> 00:00:39,640
Speaker 1: bind the iron atom very loosely. When blood passes through

9
00:00:39,640 --> 00:00:42,400
Speaker 1: the lungs, the iron atoms and hebi globe pick up

10
00:00:42,400 --> 00:00:45,640
Speaker 1: oxygen atoms. When the blood flows into areas of the

11
00:00:45,640 --> 00:00:48,680
Speaker 1: body that are lacking in oxygen, the iron atoms release

12
00:00:48,760 --> 00:00:52,840
Speaker 1: their oxygen. Carbon monoxide, on the other hand, binds very

13
00:00:52,920 --> 00:00:57,320
Speaker 1: strongly to the iron and hemoglobin. Once carbon monoxide attaches

14
00:00:57,520 --> 00:01:00,720
Speaker 1: it's very difficult to release it. So if you breathe

15
00:01:00,720 --> 00:01:03,720
Speaker 1: in carbon monoxide, it sticks to your hemoglobe and it

16
00:01:03,760 --> 00:01:07,560
Speaker 1: takes up all the oxygen binding sites. Eventually, your blood

17
00:01:07,600 --> 00:01:11,240
Speaker 1: loses all of its ability to transport oxygen and you suffocate.

18
00:01:11,880 --> 00:01:15,679
Speaker 1: Because carbon monoxide binds the hemoglobe and so strongly, you

19
00:01:15,720 --> 00:01:19,080
Speaker 1: can be poisoned by carbon monoxide, even at very low

20
00:01:19,160 --> 00:01:22,319
Speaker 1: concentrations if you're exposed for a long period of time.

21
00:01:22,880 --> 00:01:26,320
Speaker 1: Concentrations as low as twenty to thirty parts per million

22
00:01:26,840 --> 00:01:31,040
Speaker 1: can be harmful if you're exposed for several hours. Exposure

23
00:01:31,040 --> 00:01:34,000
Speaker 1: at two thousand parts per million for one hour will

24
00:01:34,040 --> 00:01:39,880
Speaker 1: cause unconsciousness. Many common devices produce carbon monoxide, including cars,

25
00:01:40,360 --> 00:01:46,480
Speaker 1: gas appliances, woodstoves, and cigarettes. For moralns, and thousands of

26
00:01:46,520 --> 00:01:52,880
Speaker 1: other topics. Is it how stuff works dot com