Upload
mohamed-omran
View
781
Download
0
Tags:
Embed Size (px)
DESCRIPTION
minerals, calcium, phosphorus, potassium, sodium ,chloride, iodine , sulfur , chromium ,
Citation preview
1
2
Minerals
Dr
Mohamed Mostafa Omran
Faculty of Sciences, Helwan University
What Are Minerals?
• Inorganic elements essential to the nutrition of humans
• Minerals are essential to body function – Play several key roles in overall health and well
being • Help chemical reactions take place in cells
• Help muscles contract
• Keep the heart beating
• Two groups – Major minerals
– Trace minerals
What Are Minerals?
• Major minerals
– Need to consume > 100 milligrams per day
– At least 5 grams of the mineral in the body
– Calcium, sodium, potassium, chloride, phosphorus, magnesium, and sulfur
What Are Minerals?
• Trace minerals
– Need to consume > 20 milligrams per day
– The body contains less than 5 grams total
– Iron, zinc, copper, selenium, chromium, iodide, manganese, molybdenum, and fluoride
Mineral Balance • Body maintains tight control over mineral balance
– GI tract
Regulates absorption from food based on the body’s need
Minerals in gastric juices and that slough-off intestinal cells are either excreted in the feces or reabsorbed through the large intestine
– Kidneys
Excretes excess and reabsorbs the minerals when the body needs them
Mineral Functions
• Minerals work together to perform important functions in the body
– Fluid and electrolyte balance
– Blood formation
– Building healthy bones
– Maintaining a healthy immune system
Minerals Help Maintain Fluid Balance
• Minerals play a key role in fluid balance in the cells
– Extracellular minerals – sodium and chloride
– Intracellular mineral – potassium with the help of calcium, magnesium, and sulfur.
Mineral Participate as Cofactors
• Cofactor – substance that helps catalyze a reaction
• Minerals serve as cofactors in
– Antioxidant systems
– Energy production
– Muscle contraction
– Nerve transmission
Minerals Make Up Bones and Teeth
• Minerals make up the crystalline structure (hydroxyapatite) that gives strength to bones and teeth.
– Major minerals
• Calcium, phosphorus, and magnesium
– Trace mineral
• Flouride
Ca Food Sources
• Milk • Cheese • Seafood
Thermolysin: is a thermostable neutral metalloproteinase enzyme produced by
the +ve Gram bacteria Bacillus thermoproteolyticus.
It requires one zinc ion for enzyme activity and four calcium ions for structural
stability.
Thermolysin specifically catalyzes the hydrolysis of peptide
bonds containing hydrophobic amino acids.
Thermolysin use in the synthesis of aspartame. It is composed of aspartic acid
and phenyl alanine. Aspartame which acts as sweetening agent being used in
replacement of cane sugar.
Food sources of phosphorus
The main food sources for
phosphorus are foods
containing protein.
For example, egg, milk,
meat, and soya
Fibroblast growth factor 23 or FGF23
• FGF23 is a member of the fibroblast growth factor (FGF) family which is
responsible for phosphate metabolism.
• The main function of FGF23 seems to be regulation of phosphate concentration in
plasma.
• FGF23 is secreted by Osteoblasts and Osteoclasts in response to
elevated Calcitriol.
• FGF23 decreases the reabsorption and increases excretion of phosphate.
1. Calcitriol increases blood calcium levels ( [Ca2+] ) by promoting absorption of
dietary calcium from the gastrointestinal tract and increasing renal
tubular reabsorption of calcium thus reducing the loss of calcium in the urine.
2. Calcitriol also stimulates release of calcium from bones.
3. Calcitriol acts in concert with parathyroid hormone (PTH) in all three of these
roles.
For instance, PTH also indirectly stimulates osteoclasts. However, the main
effect of PTH is to increase the rate at which the kidneys excrete inorganic
phosphate (Pi), the counterion of Ca2+.
The resulting decrease in serum phosphate causes Ca5(PO4)3OH to dissolve out
of bone thus increasing serum calcium.
FGF23 decreases
reabsorption
increases
excretion of
phosphate
Magnesium functions
• Important in energy metabolism catalyst
through ATP production.
• critical to heart function.
• It activates, phosophate transferases,
decarboxylases and acyl transferases.
Potassium
Food Sources
Potassium functions
• Potassium like sodium, chloride and bicarbonate ions, plays an important role in the osmotic regulation of body fluids. Sodium mainly found in the extracellular tissues, whereas potassium principally present in the cell (intracellular).
• It plays an important role in nerve and muscle excitability.
• It plays role in carbohydrate metabolism (cofactor of propionly CoA carboxlase).
– energy metabolism, catalyst, ATP production
• critical to heart function.
POTASSIUM
Bones Extracellular Electrolyte
SODIUM
• Most of the sodium of the human body is present in the
soft tissues and body fluids; like potassium it is
concerned with the acid base balance and osmotic
regulation.
• It is a chief cation of blood-plasma and other
extracellular fluids of the body. Much of it is ingested as
common salt and excreted in urine.
Sodium functions • Transmission and conduction of nerve impulses
• Responsible for osmolality of vascular fluids
• Regulation of body fluid levels
• Assists with regulation of acid-base balance by combining with Cl or HCO3 to regulate the balance.
• Sodium shifts into cells and potassium shifts out of the cells (sodium pump)
sodium-potassium pump (Na+/K+ ATPase)
• The sodium-potassium pump was discovered in the 1950s by a Danish scientist, Jens Christian Skou, who was awarded a Nobel Prize in 1997.
• Failure of the Na-K pumps can result in swelling of the cell.
• A cell's osmolarity is the sum of the concentrations of the various ion species and many proteins and other organic compounds inside the cell.
• When this is higher than the osmolarity outside of the cell, water flows into the cell through osmosis. This can cause the cell to swell up and lyse. The Na-K pump helps to maintain the right concentrations of ions. Furthermore, when the cell begins to swell, this automatically activates the Na-K pump
The Sodium-Potassium Pump
Slide number: 1
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Extracellular
fluid with high
concentration
of Na+
Cytoplasm
with high
concentration
of K+
1
Three Na+
bind to the
cytoplasmic
side of the
protein.
2
Phosphate is
transferred
from ATP to
the protein.
3
Phosphorylation
changes the
shape of the
protein, moving
Na+ across the
membrane.
4
K+ binds to
the protein,
causing
phosphate
release.
5
Release of
phosphate
changes the
shape of the
protein,
moving K+ to
the cytoplasm.
Na+
ATP ADP P
Na+
P
K+
P K+
04.10 The Sodium-Potassium Pump
Slide number: 2
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Extracellular
fluid with high
concentration
of Na+
Cytoplasm
with high
concentration
of K+
1 Three Na+ bind to the
cytoplasmic side of the protein.
Na+
ATP ADP
P
04.10 The Sodium-Potassium Pump
Slide number: 3
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Extracellular
fluid with high
concentration
of Na+
Cytoplasm
with high
concentration
of K+
1 Three Na+ bind to the
cytoplasmic side of the protein.
2 Phosphate is transferred from
ATP to the protein.
04.10 The Sodium-Potassium Pump
Slide number: 4
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Extracellular
fluid with high
concentration
of Na+
Cytoplasm
with high
concentration
of K+
1 Three Na+ bind to the
cytoplasmic side of the protein.
2 Phosphate is transferred from
ATP to the protein.
3 Phosphorylation changes the
shape of the protein, moving
Na+ across the membrane.
Na+
P
04.10 The Sodium-Potassium Pump
Slide number: 5
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Extracellular
fluid with high
concentration
of Na+
Cytoplasm
with high
concentration
of K+
1 Three Na+ bind to the
cytoplasmic side of the protein.
2 Phosphate is transferred from
ATP to the protein.
3 Phosphorylation changes the
shape of the protein, moving
Na+ across the membrane.
4 K+ binds to the protein, causing
phosphate release. P
K+
04.10 The Sodium-Potassium Pump
Slide number: 6
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Extracellular
fluid with high
concentration
of Na+
Cytoplasm
with high
concentration
of K+
1 Three Na+ bind to the
cytoplasmic side of the protein.
2 Phosphate is transferred from
ATP to the protein.
3 Phosphorylation changes the
shape of the protein, moving
Na+ across the membrane.
4 K+ binds to the protein, causing
phosphate release.
5 Release of phosphate changes
the shape of the protein,
moving K+ to the cytoplasm.
K+
Corticotropin-releasing hormone (CRH)
Adrenocorticotropic hormone (ACTH)
Brain natriuretic peptide (BNP)
atrial natriuretic peptide (ANP)
Chlorine
Extracellular Electrolyte
Food Sources • Salt • Seafood
CHLORIDE • Chloride is principle anion of body fluids.
• It is associated with sodium and potassium in acid-base balance and
osmosis.
• plays an important role in gastric secretion (hydrochloric acid) and
digestion.
• It is excreted in urine and in perspiration with sodium and potassium.
• Sources: Chloride is part of sodium chloride.
• With exception of fish and meat meals, the chloride contents of most
of the foods is very low.
• rarely lacking, dehydration due to water deficiency.
Chloride Functions
• Found in extracellular fluids
• Changes the blood osmolality
• Goes with Na in retention of water
• Assists with regulation of acid-base balance
• Chloride combines with hydrogen to form hydrochloric acid in the stomach
Iron
Food Sources
Iron
• Essential nutrient, vital to many of the cell’s activities.
• Iron forms : Incorporated into Hemoglobin (80%),
Myoglobin, Enzymes, Cytochromes (20 %)
• *Hemoglobin protein in the red blood cells and myoglobin
protein in the muscle cells.
– Iron present in Hb is Fe 2+ state,
– Organic/heme iron (10%) Fe2+ (more soluble).
– Inorganic/non-heme iron (90%) Fe3+ (less soluble)
Role of iron in the body
Iron has three main functions :
1. carrying oxygen from the lungs to the rest of the body.
2. Aiding energy production. Iron is constituent of several enzymes
including : iron catalase, peroxidase, and cytochrome enzymes.
• Iron Absorption and Metabolism
– Free iron is toxic to cells as it acts as a catalyst in the
formation of free radicals. Hence, within cells, iron is
stored in a protein complex as ferritin (major) or
hemosiderin.
–Apoferritin can take up to 4300 atoms of iron per
molecule.
– Blood transferritin: transfers the iron to the rest of the
body. Transferrin receptors are present on most body
cells, especially on cells which synthesize heme.
• Absorption-Enhancing Factors:
– MFP factor: a factor associated with the digestion of Meat, Fish, and Poultry that enhances nonheme iron absorption.
– Vitamin C (ascorbic acid).
Ascorbate increases absorbtion (by reducing).
– Citric acid and lactic acid from foods and HCl acid from stomach.
– Sugars.
• Absorption-Inhibiting Factors: – Phytate and fibers (grains and vegetables).
– Oxalates (spinach).
– Calcium and phosphorus (milk).
– EDTA (food additive).
– Tannic acid (and other polyphenols in tea and coffee).
Iron Absorption
Average percentage of iron absorbed from selected foods by healthy adults.
Iron Absorption from Food
People absorb more iron from foods and supplements when body
stores of iron are low than when stores of iron are high.
Macrophages engulfs old
RBCs and releases heme.
Heme oxygenase separates
them and Fe is then stored
as ferritin.
Human hemochromatosis protein also known as the HFE protein is
a protein which in humans is encoded by the HFE gene. this protein functions to
regulate iron absorption by regulating the interaction of the transferrin receptor
With transferrin.
Iron Deficiency Anemia
Normal Red Blood Cells Iron Deficiency Anemia--
Small microcytic and
pale hypochromic cells
contain less hemoglobin.
Sulfur
Components of some proteins
Food Sources
Protein-rich foods
formation of collagen - connective tissue
Keratin- helping to give strength, shape, hardness of skin and hair
Taurine is found in bile acids, used in digestion
Glutathione (glutamic acid+cysteine+glycine), protects against hemolysis of RBC by breaking H2O2 which causes cell damage (antioxidant).
The mucopoly-saccharides may contain chondroitin sulfate, which is important to joint tissues.
Zinc
Oysters
poultry
red meat
dairy products
Zinc functions • It helps with the human immune
system, DNA synthesis, and cells.
• It plays a vital role in growth and developmental functions in pregnant woman, children and adolescents.
• It is required for proper sense of taste and smell.
• Essential for proper reproduction in males, requires for spermatogenesis
Immune System
DNA
Synthesis
Growth and
Development
Zinc deficiency
• A deficiency is Zinc may
cause :
– growth retardation
– loss of appetite
– impairment of
immune functions.
– hair loss
– Low sperm count
drink water
cheese
seafood
Tea
Fluorine
• Fluorine prevents tooth decay and cavities and strengths the enamel.
• If there is a deficiency of fluorine during the growing period, it will result in dental caries and tooth decay.
• Discoloration and pitting of tooth enamel caused by excess fluoride during tooth development.
Copper
Red Blood Cells
Food Sources
• Nuts
• Shellfish
• Liver
1. Enzymes catalyze the oxidation of ferrous
iron to ferric iron are copper enzyme
2. Helps in the absorption of iron absorption of
iron and Synthesis of hemoglobin.
3. Superoxide dismutases is Cu enzyme that catalyze the hydrolysis of superoxide (O2−) into O2 and H2O ( antioxidant).
Iodine
Thyroid
Food Source Iodized Salt
Absorption
Upper small
intestine
Transport
Binding loosely
to plasma proteins
Storage
80% in thyroid gland
Excretion
2/3rd in urine
Required for the synthesis of thyroid
hormones T4 and T3
Chemistry of Thyroid hormones
• Thyroid hormones are derivatives of the amino acid tyrosine bound covalently to iodine.
Goiter
Soybeans
Fruits
Vegetables
1. It may activate certain enzymes related to glucose.
2. It aid in prolactin production, and thus be involved in human breast milk production.
Whole-grains
mushrooms
dark chocolate,
nuts
Chromium (closely with insulin )
1. It is very important in order for insulin to function
2. It works closely with insulin to facilitate the uptake of glucose into cells (Glucose Tolerance Factor).
3. It participates in the in the transport of amino acids into the cells (Heart, Liver).