Essential and Trace Ions: Iron

Essential and Trace Ions

• Iron is crucial for cellular metabolic processes, particularly electron transport in the respiratory chain and oxygen transport in higher organisms.
• Iron's ability to exist in various oxidation states enables it to form coordination compounds essential for its functions.
• Iron is found in various forms:
  • Hemoglobin in blood for oxygen transport.
  • Transferrin in plasma for iron transport.
  • Myoglobin in tissues for cellular respiration.
  • Ferritin and Hemosiderin in tissues for iron storage.
• Hemoglobin consists of four protein chains, each containing a heme unit with a porphyrin ring and ferrous iron.
• Ferritin is a water-soluble iron storage protein made up of apoferritin and a colloidal ferric hydroxide-phosphate complex.
• Hemosiderin is a water-insoluble iron storage protein, potentially a dehydrated form of ferritin.
• Transferrin is a glycoprotein in blood plasma responsible for transporting iron.
• Iron transport into the intestinal mucosa is facilitated by molecules like ascorbic acid and fructose, which keep iron soluble.
• Iron deficiency can lead to anemia, characterized by low red blood cell count or reduced haemoglobin content, resulting in impaired oxygen carrying capacity.
• Anemia can be caused by various factors like blood loss, blood destruction, or decreased blood formation.
• Iron supplements must be biologically available (water-soluble) and non-irritating.
• Sustained-release iron formulations minimize irritation.
• Parenteral iron preparations are used when oral iron is ineffective or contraindicated, such as in malabsorption or gastrointestinal irritation.
• Iron poisoning is serious and can be fatal, especially in children.
• Iron poisoning is treated with gastric lavage, administration of salts to form insoluble iron salts, oral deferoxamine, and chelation therapy with deferoxamine mesylate.
• Oral iron can interfere with tetracycline absorption.
• Ferrous sulfate, ferrous fumarate, and ferrous gluconate are common oral iron preparations.
• Iron dextran injection (Imferon) and iron sorbitex injection (Jectofer) are parenteral iron preparations used when oral therapy is ineffective or contraindicated.

Copper is an essential trace mineral that plays a crucial role in various physiological processes within the body. It is a key component in the formation of red blood cells, contributing to iron metabolism by aiding in the effective utilization of iron. Copper is also involved in the synthesis of collagen and elastin, both of which are important for maintaining the health of connective tissues, skin, and blood vessels.

Additionally, copper acts as a cofactor for several important enzymes, including cytochrome c oxidase, which is involved in the electron transport chain, facilitating cellular energy production. Other enzymes that require copper for their activity include superoxide dismutase, which plays a critical role in the body's defense against oxidative stress.

Dietary sources of copper include shellfish, whole grains, beans, nuts, potatoes, and dark leafy greens. The recommended daily intake of copper for adults is about 900 micrograms. While copper deficiency is relatively rare, it can lead to anemia, bone abnormalities, and cardiovascular issues. On the other hand, excessive copper intake, particularly from supplements, can cause toxicity, leading to symptoms such as abdominal pain, nausea, diarrhea, and, in severe cases, liver damage.

Because of its essential functions, adequate dietary intake of copper is important for maintaining overall health and supporting numerous biochemical processes in the body.

• Copper is essential for various enzymes, haemoglobin synthesis, and bone formation.
• Copper is distributed throughout the body, primarily in enzymes and proteins.
• Copper absorption occurs in the stomach and upper small intestine.
• Copper is transported in the blood as a copper albumin complex and then stored in the liver bound to ceruloplasmin.
• Copper plays roles in various metabolic processes:
  • Haemoglobin formation by facilitating iron absorption and stimulating enzymes involved in haeme and globin biosynthesis.
  • Oxidative phosphorylation by being a constituent of cytochrome oxidase.
• Copper deficiency can lead to anemia and other health problems.

Selenium

• Selenium is needed for cellular respiration and acts as an antioxidant in conjunction with vitamin E.
• Selenium sulfide is used for the treatment of seborrheic dermatitis (dandruff).

Sulfur

• Sulfur is widely distributed in the body, primarily in:
  • Sulfhydryl groups of cysteine in proteins.
  • Disulfide linkages in protein from cystine.
  • Mucopolysaccharides and sulfolipids as sulfate salts and esters.
• Sulfur is obtained from dietary sources.
• Sulfur has been used therapeutically as a cathartic, parasiticide, and stimulant.

Iodine (Iodide)

• Iodine is essential for the synthesis of thyroid hormones, triiodothyronine (T3) and thyroxine (T4).
• Iodine is absorbed as iodide.
• Iodine is used in thyroid hormone formation and has pharmacological actions as a fibrinolytic agent, expectorant, and bactericidal agent.
• Iodine deficiency leads to thyroid enlargement.
• Iodine uptake is influenced by thyroid tissue characteristics, blood iodide levels, and the level of thyroid-stimulating hormone (TSH).

This quiz covers the vital role of iron in cellular metabolism, focusing on its forms, functions, and significance in oxygen transport. Explore the concepts of hemoglobin, transferrin, ferritin, and hemosiderin, as well as the importance of iron's oxidation states. Test your understanding of these essential elements in biological systems.