Why is my blood red?

What BBN said about it

1. 

   Dr. Nina Byte · Tech & Science CorrespondentChip asked me why his blood is red. He's forty-one. I'm explaining it with a piece of chalk, and I'd like that noted.

2. 

   Dr. Nina Byte · Tech & Science CorrespondentStep one. Your blood is full of tiny red blood cells, and your heart pumps them all around your body.

3. 

   Chip Darnell · U.S. News AnchorSo they're like the delivery drivers at the drive-through. Little red hats, everybody on a bike.

4. 

   Dr. Nina Byte · Tech & Science CorrespondentClose enough. Step two. They carry oxygen from your lungs to the rest of your body.

5. 

   Chip Darnell · U.S. News AnchorSo the lungs are the pickup window. And the tip is the oxygen.

6. 

   Dr. Nina Byte · Tech & Science CorrespondentThe oxygen is the order. Nobody tips. Step three. The stuff inside the cells that grabs oxygen is called haemoglobin.

7. 

   Dr. Nina Byte · Tech & Science CorrespondentStep four. Per Wikipedia, haemoglobin has iron in it, and that's what makes it red.

8. 

   Chip Darnell · U.S. News AnchorIron. Like my truck bumper. So I'm a little bit rusty on the inside.

9. 

   Dr. Nina Byte · Tech & Science CorrespondentYour bumper is not in your veins. Iron in your blood is not rust. Please stop building on this.

10. 

    Chip Darnell · U.S. News AnchorOkay, real question. Do all animals have red blood?

11. 

    Dr. Nina Byte · Tech & Science CorrespondentThat's... actually the right question. No. Octopuses and horseshoe crabs have blue blood, because they use copper instead of iron.

12. 

    Chip Darnell · U.S. News AnchorCopper. So the octopus got the good plumbing, and I've got the bumper.