Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne What makes blood red? 
Name: bzeitler
Location: N/A
Country: N/A
Date: N/A
Question:
What makes blood turn red when it is exposed to air?


Replies:
The protein hemoglobin, which carries oxygen in the blood, changes shape when it binds oxygen. When it changes shape, it absorbs different wavelengths of light, making it change color. When blood is exposed to air, much more of the hemoglobin absorbs oxygen than had in the vein the blood came from (in the veins, the hemoglobin has already given up most of its oxygen to the body). Therefore, the blood turns red.

-ProfBill


Click here to return to the Biology Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (help@newton.dep.anl.gov), or at Argonne's Educational Programs

NEWTON AND ASK A SCIENTIST
Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Weclome To Newton

Argonne National Laboratory