Book 1, Question 12 · Video
Why Is Blood Red? The Iron and Oxygen Secret!
What makes blood so bright red? Blood travels around your body delivering oxygen, and inside red blood cells a protein called hemoglobin holds iron that grabs onto oxygen. When iro
Read the full answer →What Crafty Clover says in this video
Intro
Hi! I'm Crafty Clover! Let's discover something amazing. Why is blood red?
The Big Idea
Have you ever wondered why blood is red? The answer is hiding inside tiny red blood cells, In a special protein with iron in it. Let's find out, in three steps!
Blood Carries Oxygen
Step one: blood carries oxygen! Your blood travels through tubes called blood vessels, all around your body, Delivering oxygen to your cells. Your cells need oxygen to make energy, so you can run, think, and play!
Hemoglobin
Step two: hemoglobin is a protein with iron. Each red blood cell is packed with hemoglobin. Inside it is iron, the same kind of metal found in some cereals and spinach! And the iron grabs onto oxygen, and holds it tight.
Iron Plus Oxygen
Step three: iron plus oxygen looks red! When the iron in hemoglobin holds oxygen, blood looks bright cherry red. Blood that has dropped off its oxygen is a darker red. But it's always red, never blue!
A Closer Look
Let's take a closer look inside a blood vessel! Red blood cells carry oxygen. There are billions of them! White blood cells fight germs. Platelets help plug cuts. And they all float in plasma, a yellowish liquid that's mostly water.
Quick Facts
Quick facts! Veins look blue through your skin, But the blood inside is always red! A single drop of blood holds millions of red blood cells. Some animals, like octopuses, have blue blood, because they use copper instead of iron!
Think Like a Scientist
Now, think like a scientist! With a grown-up, look at the veins on your wrist. What do you notice? What color do they look? Why do you think they look blue? Here's a clue: skin changes how light bounces back to your eyes. So the blood is red, even though the veins look blue!
Outro
So blood is red because of iron holding on to oxygen, delivering it everywhere you go! Remember, Crafty Clover can be found on Amazon Books, Google Bookstore, and Apple Books. Available for purchase or download! Bye for now!