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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).