Physiological roles of minerals


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Physiological roles of minerals

  1. 1. Physiological roles of minerals Dr. Siham Gritly Dr. Siham Gritly 1
  2. 2. glossary• extracellular fluid: fluid outside the cells. Extracellular fluid includes two main components; the interstitial;- fluid between cells usually high in sodium and chloride and the intravascular fluid of plasma. Extracellular fluid accounts for approximately one-third of the body’s water.• Interstitial fluid: fluid between the cells (intercellular), usually high in sodium and chloride. Interstitial fluid is a large component of extracellular fluid. Dr. Siham Gritly 2
  3. 3. • Ions; atoms or molecules that have gained or lost electrons and therefore have electrical charges. Examples include the positively charged sodium ion (Na+) and the negatively charged chloride ion (Cl–).• Cations; positively charged ions.• Anions; negatively charged ions.• electrolytes: salts that dissolve in water and dissociate into charged particles called ions.• electrolyte solutions: solutions that can conduct electricity. Dr. Siham Gritly 3
  4. 4. Homeostasis -a term used to describe a condition of normalcy in the internal body environment• Osmotic pressure- is the amount of pressure required to oppose osmosis (water movement) into a solution across semi-permeable membrane.• Osmosis is the movement of water across a semi- permeable membrane Dr. Siham Gritly 4
  5. 5. Chemical symbols of major minerals• K = potassium• P = phosphorus• Mg = magnesium• S = sulfate• Na = sodium• Cl = chloride• Fe = iron Dr. Siham Gritly 5
  6. 6. Cations (positively charged ions) of human fluids• Cation; -a positively charged ion or electrolyte; sodium, potassium, calcium and magnesium (extracellular fluid) sodium, potassium, magnesium (intracellular fluid)• Sodium (Na+)• Potassium (K+)• Calcium (Ca++)• Magnesium (Mg++) Dr. Siham Gritly 6
  7. 7. Anions (negatively charged ions) of human fluidsAnion; -a negatively charged ion or electrolytes; chloride, bicarbonate, phosphate, sulfate, protein and organic acids (extracellular fluid). chloride, bicarbonate, phosphate and protein (intracellular fluid)• Chloride (Cl−)• Bicarbonate (HCO3−)• Phosphate (HPO4=)• Sulfate (SO4=)• Organic acids (lactate, pyruvate)• Proteins Dr. Siham Gritly 7
  8. 8. Minerals• Are inorganic regulators needed for different functions inside the body.• Do not provide energy but involved in generation of energy through their metabolic function• provide a good medium for the protoplasmic activities (permeability of cells membrane and normal functioning of the cell, irritability of muscle and nerve cells• maintaining body fluid balance (osmotic pressure)• regulation of acid-base balance• for structural units (bones and teeth• haemoglobin and thyroxin formation• some are cofactors in the enzymatic reactions Dr. Siham Gritly 8
  9. 9. Physiological functions of minerals• growth and development (used in building blocks for body tissues such as bones, teeth, muscles or act as main components of hemoglobin)• They are found in compounds essential for the functioning of the body, e.g., iodine in thyroxin, zinc in insulin, Cobalt in Vitamin B12, sulphur in thiamine and iron in hemoglobin.• As constituents of soft tissues, such as tissue protein, cell bodies and muscles, they are responsible for their proper functioning. Dr. Siham Gritly 9
  10. 10. • metabolic regulation; include enzymes known as metalloenzymes such as the cytochrome enzymes in mitochondria that facilitate ATP production• and other as zinc and copper which are part of the natural antioxidant enzymes Dr. Siham Gritly 10
  11. 11. • As constituents of body fluids,• They contribute to the osmotic pressure of body fluids.• Sodium salts and potassium salts are present in the intracellular fluids that influence their osmotic pressure. Dr. Siham Gritly 11
  12. 12. • maintenance of neutrality in blood and body tissues, this is by;• preventing the accumulation of too much acid or alkali.• The chief base forming elements are sodium, potassium, calcium and magnesium.• The acid forming elements are chlorine, phosphorus and sulphur. Dr. Siham Gritly 12
  13. 13. • Calcium, Potassium and Sodium maintain the normal rhythm in- heart beat.• They help nerves in maintaining a normal response to stimuli-especially by Calcium.• They are essential for clotting of blood. Calcium is responsible for clot formation. Dr. Siham Gritly 13
  14. 14. • Minerals classified into;• 1-macrominerals; required in excess (100mg/day); sodium, magnesium, phosphorous, sulfur, chlorine, potassium and calcium• 2-microminerals; required in less than 100mg/day essential trace elements are manganese, iron, cobalt, nickel, copper, zinc, selenium,, and iodine additional to boron, chromium, fluoride, and silicon. Dr. Siham Gritly 14
  15. 15. Electrolytes• Electrolytes are the electrically charged minerals that when dissolved in water or another solvent, forms or dissociates into ions (electrically charged particles conduct electric current).• Electrolytes are distributed throughout the fluid compartments of the body. The solution is known as electrolyte solution• Common electrolytes are bases, acids and salts Dr. Siham Gritly 15
  16. 16. the major electrolytes are in body fluids are sodium, potassium, chloride, bicarbonate, sulfate, magnesium and calcium.• When dissociate form ions particles carrying a positive (cation) or negative (anion) electric charges – Cations – carrying a positive electric charge • Na+, K+ , Ca2+, H+ – Anions – carrying negative electric charge • Cl-, HCO3- , PO43-• Non-electrolytes - Uncharged • Proteins, urea, glucose, O2, CO2 Dr. Siham Gritly 16
  17. 17. Electrolyte balance• Electrolytes (charged minerals) in the fluids help distribute the fluids inside and outside the cells, thus ensuring the appropriate water balance and acid-base balance to support all life processes.• Excessive losses of fluids and electrolytes disturb these balances, and the kidneys play a key role in restoring homeostasis. Dr. Siham Gritly 17
  18. 18. • In all electrolyte solutions, anion and cation concentrations are balanced (the number of negative and positive charges are equal).• If an anion enters the fluid, a cation must accompany it or another anion must leave so that electrical neutrality will be maintained.• Thus, whenever sodium (Na+) ions leave a cell, potassium (K+) ions enter, moving, opposite directions. Dr. Siham Gritly 18
  19. 19. Minerals with special functions; Macro-minerals metabolic role of sodium, potassium & chloride• Important role in;• -electrical neutrality• -osmotic pressure• -acid-base balance• Na˖ is the majorcation of extracellular fluids• K⁻ is intracellular fluids• Cl⁻ is the major anion in extracellular fluid Dr. Siham Gritly 19
  20. 20. • *Sodium is an Extracellular cation (Na+) (about 90%), functions in the regulation of ATP-dependent channels with potassium. These channels are referred to as Na+/K+- ATPases and their primary function is in the transmission of nerve impulses in the brain.• Level in blood controlled by aldosterone, ANP, and ADH.• 1-In the case of sodium, excessive sodium can cause hypernatraemia,• and low sodium levels can cause hyponatraemia Dr. Siham Gritly 20
  21. 21. • *Potassium (K+) is major intracellular cation• Almost the presence of (K+) found in the cells• About 2% found in extracellular fluid• a key circulating electrolyte• involved in the regulation of ATP-dependent channels along with sodium.• These channels are referred to as Na+/K+-ATPases• Na+/K+ Adenosine triphosphate pump actively transports Na+ out of the cells and K+ into the cells in a 3:2 ratio to maintain the difference in Potassium content between ECF and ICF Dr. Siham Gritly 21
  22. 22. • Potassium maintain the intracellular;-• -osmotic pressure• -water balance• -acid-base balance• -Cofactor for several glycolytic enzymes• -transmission of nerve impulses• -activity and synthesis of nuclear and protein depend of the presence of potassium Dr. Siham Gritly 22
  23. 23. • Potassium level in the plasma may cause;• 1-hyperkalameia; increase serum K in the plasma• 2-hypokalameia; decrease serum level in the plasma Dr. Siham Gritly 23
  24. 24. • Chlorine (Cl⁻) present as chloride ion. It is the major anion in the extracellular fluid• Main function;• -regulate water balance (osmotic pressure and acid base) as it is the part of NaCl• -nerve impulse conduction• -hydrochloric acid formation in the stomach Dr. Siham Gritly 24
  25. 25. • Plasma level of chloride change might cause;• abnormal metabolism of Na+ & Cl⁻ that might lead to;-• 1-hyperchloraemia• 2-hypochloremia Dr. Siham Gritly 25
  26. 26. Macro-minerals metabolic role of calcium, phosphorous & magnesium• Calcium, phosphorus and magnesium for cell metabolism, and as structural units (bone and teeth)• Calcium (Ca++) a common electrolyte carrying positive electrical charge (cation).• Calcium present in intracellular and extracellular fluid• About 99% of body calcium is in the bone, the rest in the ECF.• Nearly 50% of body calcium is ionized (free), whereas the remainder is complexes to albumin(40%) and anions such phosphate (10%) Dr. Siham Gritly 26
  27. 27. • Function of intracellular calcium;• -muscle contraction• -release of hormones (neurotransmitter & neuromodulators• -activation of some enzyme• -Inter in glycogen metabolism• -cell division Dr. Siham Gritly 27
  28. 28. • Function of extracellular calcium• -maintain extracellular fluid calcium concentration• -bone mineralization• -blood coagulation• -membrane excitability• -muscle contraction Dr. Siham Gritly 28
  29. 29. • Phosphorous• Phosphorous is required in the synthesis of nucleic acids and high-energy compounds such as ATP.• It is also important in the maintenance of pH balance.• Act as part of a major buffer system (phosphoric acid and its salts).• Phosphorus is also part of DNA and RNA and is therefore necessary for all growth.• Many enzymes and the B vitamins become active only when a phosphate group is attached.• The high-energy compound ATP uses three phosphate groups to do its work. Dr. Siham Gritly 29
  30. 30. • Lipids containing phosphorus as part of their structures (phospholipids) help to transport other lipids in the blood.• Phospholipids are also the major structural components of cell membranes, where they control the transport of nutrients into and out of the cells.• Some proteins, such as the casein in milk, contain phosphorus as part of their structures (phosphoproteins• parathyroid hormone (PTH) regulate phosphorous balance. Dr. Siham Gritly 30
  31. 31. • Magnesium (Mg++) : a cation within the body’s cells, active in many enzyme systems• More than half of the body’s magnesium is in the bones.• Much of the rest is in the muscles and soft tissues, with only 1 percent in the extracellular fluid.• As with calcium, bone magnesium may serve as a reservoir to ensure normal blood concentrations. Dr. Siham Gritly 31
  32. 32. • Magnesium is necessary for energy metabolism. It participates in hundreds of enzyme systems.• A major role of magnesium is as a catalyst in the reaction that adds the last phosphate to the high- energy compound ATP, making it essential to the body’s use of glucose;• Involved in the synthesis of protein, fat, and nucleic acids; and the cells’ membrane transport systems. Dr. Siham Gritly 32
  33. 33. • Together with calcium, magnesium is involved in muscle contraction and blood clotting: calcium promotes the processes, whereas magnesium inhibits them.• This dynamic interaction between the two minerals helps regulate blood pressure and lung function.• supports the normal functioning of the immune system Dr. Siham Gritly 33
  34. 34. • Aldosterone controls magnesium concentrations in the extracellular fluid.• Low Mg++ levels result in an increased aldosterone secretion, and the aldosterone increases Mg++ reabsorption by the kidneys Dr. Siham Gritly 34
  35. 35. Minerals with special functions; Micro-mineralsmetabolic role of cobalt Co, copper Cu, fluorine F, iodine I2,iron Fe, manganese Mn, chromium Cr, zinc Zn, selenium Se• cobalt (Co); central in corrin ring of vitamin B12• Deficiency result in pernicious anemia of vitamin B12• Revision of vitamin cyanocoblamin B12 is required Dr. Siham Gritly 35
  36. 36. • Chromium (Cr) needed in small amount which is essential for certain biological function such as;-• -control of glucose and lipid metabolism• -as cofactor for insulin in increasing glucose utilization and transport of amino acids into cells• -lower cholesterol level Dr. Siham Gritly 36
  37. 37. • Manganese (Mn) is involved in reactions of protein and fat metabolism, promotes a healthy nervous system, necessary for digestive function, bone growth, and immune function. In addition, manganese is necessary for the proper function of super oxide dismutase (SOD) which is an enzyme required for preventing super oxide anions from damaging cells. Dr. Siham Gritly 37
  38. 38. • Copper (Cu) is involved in the formation of red bloods cells, the synthesis of hemoglobin• Involve in oxidation reduction reactionsas it is an integral comonent of many metalloenzume includingcytochrome oxidase, superoxide dimutase, tryptophan dioxygenase, ferroxidase-• iron absorption through ferroxidase that oxidize ferrous ion to ferric ion.• Copper is also involved in the proper processing of collagen (the most abundant protein in the body) and thus, is important in skin, bone, and connective tissue production. Dr. Siham Gritly 38
  39. 39. • Iodine (I2) is required for the synthesis of the thyroid hormones (triiodothyronine T3 and tetraiodothyronine T4)• Deficiency leads to cretinism in children and goiter in adult• Cretinism;- deficiency during pregnancy lead to neonatal hypothyrodism which result in cretinism in children characterized by mental retardation, dwarfism, retarded development Dr. Siham Gritly 39
  40. 40. • Goiter characterized by enlargement of thyroid gland, and impairment of thyroxin production Dr. Siham Gritly 40
  41. 41. • Iron (Fe), synthesis of haem compound such as haemoglobin, myoglobin, chytochromes, catalase and peroxidase• stored in the body as ferritin or haemosiderin• Ferritin is the main iron storage compound (liver, spleen and bone)• The protein compound of ferritin is apoferritin• Deficiency lead to low heamoglobin resulting in;-hypochromic microcytic anaemia Dr. Siham Gritly 41
  42. 42. • Selenium (Se) constituent of glutathione peroxidase which has antioxidant function• antioxidant protects the cell membrane against oxidative damage by H2O2• This function is important in preventing lipid oxidation and protect cell against superoxide free radicals Dr. Siham Gritly 42
  43. 43. • Zinc (Zn) is found as a co-factor in over 300 different enzymes and thus is involved in a wide variety of biochemical processes.• Zinc interacts with the hormone insulin to ensure proper function and thus this trace mineral has an important role in regulation of blood glucose levels via insulin action.• Zinc also promotes wound healing, regulates immune function, serves as a co-factor for numerous antioxidant enzymes, and is necessary for protein synthesis and the processing of collagen Dr. Siham Gritly 43
  44. 44. sulfur for three essential amino acids and thereforemany proteins (skin, hair, nails, liver, andpancreas)• Sulfur has a primary function in amino acid metabolism but is also necessary for the modification of complex carbohydrates present in proteins and lipids, however, it should be noted that in this latter function the sulfur comes from the amino acid methionine.• Function as cofactors or regulators of enzyme function Dr. Siham Gritly 44
  45. 45. • D. Voet, J. G. Voet, Biochemistry, second edition ed., John Wiley &• Sons, New York, 1995• Sareen Gropper, Jack Smith and James Groff, Advanced Nutrition and Human Metabolism, fifth ed. WADSWORTH• Melvin H Williams 2010; Nutrition for Health, Fitness and Sport. 9th ed, McGraw Hill•• Heymsfield, SB.; Baumgartner N.; Richard and Sheau-Fang P. 1999. Modern Nutrition in Health and Disease; Shils E Maurice, Olson A. James, Shike Moshe and Ross A. Catharine eds. 9th edition• Guyton, C. Arthur. 1985. Textbook of Medical Physiology. 6th edition, W.B. Company Dr. Siham Gritly 45
  46. 46. • Campbell, Neil A.; Brad Williamson; Robin J. Heyden (2006). Biology: Exploring Life. Boston, Massachusetts: Pearson Prentice Hall• A. Burtis, Edward R. Ashwood, Norbert W. Tietz (2000), Tietz fundamentals of clinical chemistry• Maton, Anthea; Jean Hopkins, Charles William McLaughlin, Susan Johnson, Maryanna Quon Warner, David LaHart, Jill D. Wright (1993). Human Biology and Health. Englewood Cliffs, New Jersey, USA: Prentice Hall. pp. 52–59• Maitland, Jr Jones (1998). Organic Chemistry. W W Norton & Co Inc (Np). p. 139. ISBN 0-393-97378-6.• Nelson DL, Cox MM (2005). Lehningers Principles of Biochemistry (4th ed.). New York, New York: W. H. Freeman and Company.• Matthews, C. E.; K. E. Van Holde; K. G. Ahern (1999) Biochemistry. 3rd edition. Benjamin Cummings.• Y Dr. Siham Gritly 46