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Erythrocytes: Hemoglobin quiz #3 Flashcards

Erythrocytes: Hemoglobin quiz #3
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  • Describe the structure of a hemoglobin molecule and explain how this structure enables it to carry oxygen.
    Hemoglobin is composed of four protein subunits (two alpha and two beta), each containing a heme group with a central iron atom. Each iron atom can bind one oxygen molecule, allowing a single hemoglobin molecule to carry up to four oxygen molecules.
  • Why is blood never actually blue, and what causes the difference in color between oxygenated and deoxygenated blood?
    Blood is never actually blue; oxygenated blood is bright red due to hemoglobin bound to oxygen, while deoxygenated blood is dark red because hemoglobin is not bound to oxygen. The blue color often used in diagrams is just for visual distinction.
  • What is the primary function of hemoglobin in red blood cells?
    Hemoglobin's primary function is to transport oxygen and carbon dioxide gases in the blood.
  • How many hemoglobin molecules are found in a single red blood cell?
    A single red blood cell contains about 250 million hemoglobin molecules.
  • How many oxygen molecules can one hemoglobin molecule carry at maximum, and why?
    One hemoglobin molecule can carry up to four oxygen molecules because it has four subunits, each with a heme group that binds one oxygen.
  • Describe the structure of a hemoglobin molecule.
    Hemoglobin is made of four protein subunits (two alpha and two beta), each containing a heme group with a central iron atom.
  • How does hemoglobin bind oxygen and carbon dioxide differently?
    Oxygen binds to the iron atom in the heme group, while carbon dioxide binds to amino groups on the protein, not the heme.
  • Why is hemoglobin's ability to bind gases reversibly important?
    Reversible binding allows hemoglobin to pick up oxygen in the lungs and release it in tissues, and to pick up carbon dioxide in tissues and release it in the lungs.
  • Why is blood never actually blue, and what causes the color difference between oxygenated and deoxygenated blood?
    Blood is always red; oxygenated blood is bright red due to oxygen-bound hemoglobin, while deoxygenated blood is dark red because hemoglobin is not bound to oxygen.
  • What role does hemoglobin play in carbon dioxide transport compared to oxygen transport?
    Hemoglobin plays a larger role in oxygen transport, while most carbon dioxide is transported by blood plasma rather than hemoglobin.