{"id":12292,"date":"2018-06-01T02:20:09","date_gmt":"2018-06-01T02:20:09","guid":{"rendered":"http:\/\/www.lifeandnews.com\/articles\/?p=12292"},"modified":"2018-06-02T02:23:44","modified_gmt":"2018-06-02T02:23:44","slug":"blood-in-your-veins-is-not-blue-heres-why-its-always-red","status":"publish","type":"post","link":"https:\/\/www.lifeandnews.com\/articles\/blood-in-your-veins-is-not-blue-heres-why-its-always-red\/","title":{"rendered":"Blood in your veins is not blue \u2013 here’s why it’s always red"},"content":{"rendered":"

Marisia Fikiet<\/a>, University at Albany, State University of New York<\/a><\/em> and Igor Lednev<\/a>, University at Albany, State University of New York<\/a><\/em><\/span><\/p>\n

Whenever you see blood outside your body, it looks red. Why?<\/p>\n

\n \"\"<\/a>
\n Heme is the part of the hemoglobin molecule that latches onto oxygen and then releases it to tissues around the body.<\/span>
\n Waikwanlai<\/a>, CC BY<\/a><\/span>
\n <\/figcaption><\/figure>\n

Human blood is red because of the protein hemoglobin, which contains a red-colored compound called heme that\u2019s crucial for carrying oxygen through your bloodstream. Heme contains an iron atom which binds to oxygen<\/a>; it\u2019s this molecule that transports oxygen from your lungs to other parts of the body.<\/p>\n

Chemicals appear particular colors to our eyes based on the wavelengths of light they reflect. Hemoglobin bound to oxygen absorbs blue-green light, which means that it reflects red-orange light<\/a> into our eyes, appearing red. That\u2019s why blood turns bright cherry red when oxygen binds to its iron. Without oxygen connected, blood is a darker red color<\/a>. <\/p>\n

Carbon monoxide, a potentially deadly gas, can also bind to heme<\/a>, with a bond around 200 times stronger than that of oxygen. With carbon monoxide in place, oxygen can\u2019t bind to hemoglobin, which can lead to death. Because the carbon monoxide doesn\u2019t let go of the heme<\/a>, your blood stays cherry red, sometimes making a victim of carbon monoxide poisoning appear rosy-cheeked even in death.<\/p>\n

\n \"\"<\/a>
\n People with pale skin may think their blood is blue inside the body.<\/span>
\n eltpics<\/a>, CC BY-NC<\/a><\/span>
\n <\/figcaption><\/figure>\n

Sometimes blood can look blue through our skin<\/a>. Maybe you\u2019ve heard that blood is blue in our veins because when headed back to the lungs, it lacks oxygen. But this is wrong; human blood is never blue. The bluish color of veins is only an optical illusion. Blue light does not penetrate as far into tissue as red light. If the blood vessel is sufficiently deep, your eyes see more blue than red reflected light due to the blood\u2019s partial absorption of red wavelengths.<\/p>\n

But blue blood does exist elsewhere in the animal world. It\u2019s common in animals such as squid and horseshoe crabs, whose blood relies on a chemical called hemocyanin, which contains a copper atom<\/a>, to carry oxygen. Green, clear and even purple blood are seen in other animals<\/a>. Each of these different blood types uses a different molecule to carry oxygen rather than the hemoglobin we use. <\/p>\n

\n \"\"<\/a>
\n Horseshoe crabs\u2019 blue blood has become an important raw material for the pharmaceutical industry.<\/span>
\n AP Photo\/Steve Helber<\/a><\/span>
\n <\/figcaption><\/figure>\n

Despite exceptions, the majority of blood from animals is red. But that doesn\u2019t mean it\u2019s exactly the same as what courses through our veins. There are many variations of hemoglobin present in different species, which allows scientists to distinguish blood samples<\/a> from various animals.<\/p>\n

Over time, spilled blood that starts out red turns darker and darker as it dries and its hemoglobin breaks down into a compound called methemoglobin. As time passes, dried blood continues to change, growing even darker thanks to another compound called hemichrome. This continual chemical and color change allows forensic scientists to determine the time<\/a> a blood drop was left at a crime scene.<\/p>\n

\"TheIn our lab<\/a>, we\u2019re developing methods that look at the ratio of the different compounds that hemoglobin breaks down into. Then using computer modeling we can estimate the time since the blood was deposited<\/a> to help investigators determine if a blood stain is relevant to a crime. If the blood is a year old, it might not be important to a crime committed yesterday.<\/p>\n

Marisia Fikiet<\/a>, Ph.D. Student in Chemistry, University at Albany, State University of New York<\/a><\/em> and Igor Lednev<\/a>, Professor of Chemistry, University at Albany, State University of New York<\/a><\/em><\/span><\/p>\n

This article was originally published on The Conversation<\/a>. Read the original article<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"

Marisia Fikiet, University at Albany, State University of New York and Igor Lednev, University at Albany, State University of New York Whenever you see blood outside your body, it looks red. Why? Heme is the part of the hemoglobin molecule that latches onto oxygen and then releases it to tissues around the body. Waikwanlai, CC […]<\/p>\n","protected":false},"author":44,"featured_media":12294,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[3410],"tags":[4477,4573,4574,1700,2197],"_links":{"self":[{"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/posts\/12292"}],"collection":[{"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/users\/44"}],"replies":[{"embeddable":true,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/comments?post=12292"}],"version-history":[{"count":1,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/posts\/12292\/revisions"}],"predecessor-version":[{"id":12295,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/posts\/12292\/revisions\/12295"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/media\/12294"}],"wp:attachment":[{"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/media?parent=12292"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/categories?post=12292"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/tags?post=12292"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}