Question

Each of the following isotopes has been used medically for the purpose indicated. Suggest reasons why the particular element might have been chosen for this purpose. a. cobalt-57, for study of the body's use of vitamin \(\mathrm{B}_{12}\) b. calcium- 47 , for study of bone metabolism c. iron- 59 , for study of red blood cell function

Short answer

Cobalt-57 is used for studying the body's use of vitamin B12 as it can replace the natural cobalt in vitamin B12, and its radioactive properties can be traced in the body. Calcium-47 is used for studying bone metabolism as it can replace stable calcium in bones, and its radioactive emissions can measure the rates of bone formation and resorption. Iron-59 is used for studying red blood cell function, as it can replace stable iron in hemoglobin without affecting normal function, and its radioactive properties help track the movement and lifespan of red blood cells.

Step-by-step solution

a. Cobalt-57 for the study of the body's use of vitamin B12

Cobalt-57 is a radioactive isotope with a half-life of about 271.79 days, which decays by gamma (γ) emission. Vitamin B12 (cobalamin) is an essential nutrient for the body and has a cobalt atom at its center. The reason Cobalt-57 is used for studying the body's use of vitamin B12 is because it can replace the natural cobalt in vitamin B12 and its radioactive properties allow it to be traced in the human body. By introducing the radioactive isotope of cobalt (Cobalt-57) into vitamin B12, researchers can trace its movement, absorption, and distribution in the body through imaging techniques, providing valuable information on how the body utilizes vitamin B12.

b. Calcium-47 for the study of bone metabolism

Calcium-47 is a radioactive isotope with a half-life of about 4.536 days that decays by beta (β) emission. Calcium is an essential nutrient in the human body and is the primary component of bones and teeth. The reason Calcium-47 is used for studying bone metabolism is because it can replace the stable calcium isotope (Calcium-40) in the bones due to its similar chemical properties. When the radioactive isotope of calcium (Calcium-47) is introduced into the body, the natural calcium balance processes will lead to the incorporation of the isotope into bone tissue. By detecting the radioactive emissions, researchers can measure the rates of bone formation and resorption, providing insights into bone growth and remodeling as well as diagnosing and monitoring bone-related diseases.

c. Iron-59 for the study of red blood cell function

Iron-59 is a radioactive isotope with a half-life of about 44.5 days, which decays by beta (β) emission and gamma (γ) emission. Iron is a vital element in the human body, playing a critical role in the function of red blood cells by binding to hemoglobin protein and assisting in oxygen transport. The reason Iron-59 is used for studying red blood cell function is because it can replace the stable isotope of iron (Iron-56) present in hemoglobin, without affecting the normal function of red blood cells. By introducing the radioactive isotope of iron (Iron-59) into the body, researchers can trace where it is incorporated into red blood cells and track the movement, distribution, and lifespan of red blood cells. This information can help diagnose and monitor various blood disorders such as anemia and other hematological conditions.

Key concepts

Cobalt-57

Cobalt-57 is a fascinating radioactive isotope that has incredible applications in the medical field, particularly in studying how our body uses vitamin B12. Its half-life of about 271.79 days makes it stable enough for detailed research. Vitamin B12, also known as cobalamin, is crucial for brain health and the production of DNA. Interestingly, a cobalt atom is at the core of vitamin B12.

By using Cobalt-57, medical professionals can effectively replace the natural cobalt within vitamin B12 with the radioactive isotope. This substitution allows them to trace and visualize the movement and absorption of vitamin B12 in the body using imaging techniques. Such studies offer deep insights into how vitamin B12 is metabolized and utilized, which is essential for diagnosing and treating disorders related to this vitamin like pernicious anemia or vitamin B12 deficiency.

• Long half-life ensures extended study periods
• Allows tracing through gamma emissions
• Helps in understanding vitamin B12 absorption

Calcium-47

Calcium-47 emerges as a key player when it comes to understanding bone metabolism. With a shorter half-life of about 4.536 days, this radioactive isotope decays by beta emission, allowing researchers to track it over a concise time frame. Calcium, being the primary element in our bones and teeth, makes this isotope particularly suitable for medical studies involving the skeletal system.

When Calcium-47 is introduced to the body, it takes the place of stable calcium isotopes within the bones. This ability to seamlessly integrate into bone tissue allows scientists to measure bone formation and resorption rates through the detection of its emissions. Such information is invaluable in diagnosing and managing conditions like osteoporosis or other metabolic bone diseases.

• Short half-life suitable for quick studies
• Tracks bone tissue integration
• Monitors bone formation and resorption

Iron-59

Iron-59 offers valuable insights into the functioning of red blood cells, essential for understanding various blood-related disorders. This isotope has a moderate half-life of about 44.5 days, releasing both beta and gamma emissions. Iron is crucial for red blood cells because it is a major component of hemoglobin, the protein responsible for oxygen transport in our systems.

By introducing Iron-59 into the body, it can substitute the stable isotope Iron-56 in hemoglobin. This substitution does not disrupt the natural physiological functions of the blood cells, allowing clear observation of how red blood cells operate. Medical researchers use this information to investigate the existence and development of blood disorders such as anemia, providing critical data for patient diagnosis and treatment.

• Moderate half-life for extensive observation
• Substitutes in hemoglobin without interference
• Aids in diagnosing blood disorders