biochem

2. MINERALS
Inorganic micronutrients that serve a variety of functioins in the body
Overall function
• Act as cofactors in enzyme-catalyzed reactions.
• Take part in regulation of acid-base balance.
• In nerve conduction & muscle irritability.
• As structural elements of body tissues.
• Regulation of body fluids & transport gases.
Overall dietary sources
meat, milk, egg, fish. milk is deficient in Fe,Cu, Vit.C.
whole grains, cereals, legumes, leafy green vegetables.

3. Classification
1. Macrominerals/ principal elements: daily
requirement >100 mg i.e. Na, K, Ca, P, S, Cl, Mg.
2. Microminerals/ trace elements:
daily requirement is <100 mg. Their deficiencies can cause
serious disorders.
Further divided into:-
a). Essential: Fe, I, Cu,Zn, Co, Mn, Mo.
b). Semi essential: Fl, Se, Cr, Ni. Tn, Si.
c). Nonessential; Al. Bi, Cd, Ag, Pb, Hg.
MINERALS IN QURAN
NaCl, Fe, Cu, S, Au, Ag.

4. Iron
• Most essential trace element in body.
• Total iron content in body is 2.3--2.8 gm.
• Females have lower iron content.
• Turn over rate/day is 35 -- 40 mg.
• Male requires 10 mg/day & female 15 mg/day.
• Pregnant women require 10-15 mg/day.
• Children require 10-15 mg/day.
• Requirement varies with age, sex, wt & health.
• Daily loss in man is 0.5-- 1 mg/day through intestine.
• Iron is one way element, not excreted.
• Daily loss in woman is 1.5--2mg.
• Iron is transported by transferrin (250mg/dl).
• TIBC of transferrin is 300--360ug.
• Normal iron level in males is 120--140ug/dl.
• Normal iron level in females is 90--120ug/dl.
• Deficiency of iron causes iron deficiency anemia.

5. • TYPES:
1. Essential / functional iron.
2. Storage form of iron.
DISTRIBUTION of Iron in Body:
Protein/enzyme iron content (mg) %age
1.Haemoproteins
• Hemeoglobin 2500 60-70
• Myoglobin 400 5-10
• Heme enzymes:
catalase & peroxidas 2-3 1
2.organo-iron compounds
• Cytochromes 4-5 1
3.Storage iron:
• Ferritin 300-700 10-15
• Haemosiderin (non-heme protein)
4.Transferrin (non-heme ptotein) 6-8 1
5.Iron requiring enzymes:
• Fp, Fe-S non-heme enzymes -- 1
• Other dehydrogenases -- 1
• Non-heme enzymes -- 1

6. Transferrin
• It is non-heme iron binding glycoprotein.
• Apotranferrin is apoenzyme & Fe is prosthetic group.
• Mol. weight is 70000.
• It can bind 2 atoms of Fe in ferric state.
• Exists in plasma as plasma β-1 globulin.
• Can be saturated 30-33% with iron.
• Major function is to transport iron.
Dietary Sources of Iron:
a). Animal sources: Meat, fish, shellfish, liver, spleen, red
marrow. Cow milk is deficient in Fe, breast milk is rich in Fe.
b). Vegetable sources: Cereals, legumes, nuts& dates.
c). Endogenously from ferritin & intestinal cells.
Daily intake & absorption:
10-15 mg in diet. only 10% is absorbed. Mucosal block theory
also operates the absorption. Requirement is highly
increased in infancy, adolescence, pregnancy & lactation.

7. Factors affecting absorption
Absorption Depends on:
• Composition of diet.
• pH of intestinal milieu.
• State of individual’s health.
• Type of Fe: Heme Fe absorbed more (20-30%)
• Non-heme Fe, less absorbed 1-5%.
• Acidic pH, HCl increase absorption
• Vit. C increases Fe absorption.
• Tea, coffee, phytates & oxalates reduce
absorption.

8. IRON DEFICIENCY
Causes: poor in take, malabsorption, trauma, surgery, worms, ch.
infections, pregnancy & lactation, bleeding disorders, cancer
Iron deficiency anemia:
1. Hypochromic microcytic anemia.
2. Hb concentration low.
3. Serum ferritin level low.
4. Erythrocytes protoporphyrins high.
Iron overload: Causes:-
• Excessive absorption.
• Parental Fe therapy.
• Repeated transfusions.
Types of Fe overload:
a). Hemochromatosis: Associated with cell injury, having classic triad;
1. Micronodular cirrhosis with marked brown pigmentation.
2. Diabetes mellitus.
3. Skin pigmentation called as Bronze Diabetes.
b) Hemosiderosis / siderosis: accumulation of Fe as hemosiderin
without cell damage.
may be due to multiple blood transfusions i.e. in thalassemia
can occur due to cooking in iron utensils which increase dietary Fe.

9. COPPER
• Adult humans contain 100-150mg
• 65mg is found in muscles
• 23mg in bones & 18mg in liver
OCCURANCE
 Ceruloplasmin 96%, in serum.
 Erythrocuprein, in red blood cells.
 Hepatocuprein, in liver.
 Cerebrocuprein, in brain.
 Port of enzymes e.g cyto oxidase
MAO, Catalase, uricase
Wilson’s Disease (hepatolenticular
degeneration)
 Inherted disoorders at autosomal
recessive.
 Cu is deposited in liver , brain &
cornea.
 Cu and ceruloplasmin is low in
serum.
 Kayserfleischer ring in cornea.
 Cu is increased in urine.
IODINE
 Total iodine in body is 20-30mg
 20% of total is in thyroid glands
 1% is found as iodide ions.
 Rest occurs as in thyroglobulin.
 Deficiency leads to simple
/colloid/endemic goiter.
 Goiter is common in hilly area of
Pakistan
 Excessive in take can lead to
thyrotoxicosis.

10. ZINC
• Adult man contains 1.5 – 2.5gm in body.
• Present in α2-macroglobulin & albumin in plasma.
• Present in metallo-enzymes e.g carbonic anhydrase,
superoxidedismutase, LDH.
• Has a role in insulin secretion as PZI & GZI.
• Deficiency leads to dwarfism & hypogonadism.
COBALT
• Is integral part of vit.B12.
• Formation of cobamide coenzyme.
• Maintains normal bone marrow function.
• Act as cofactor for enzymes.
• Deficiency leads to macrocytic anemia.
FLUORINE
• Daily intake should not exceed 3mg.
• It is toxic element, lethal dose 2.5gm
• Has a role in teeth development
• Has a role in bone development
• Maintains dental health & prevents dental caries.
• Excess intake causes fluorosis & mottling of enamel.

11. SELENIUM
• Total body content is 4-10mg.
• Selenium acts as antioxidant.
• It has sparing effect on vit.E.
• Also occur as selenomethionine, selenocysteine, &
selenocystine.
• Has a role in glutathione peroxidase.
MANGANESE
 Body contains about 10-18mg
 Manly found in kidneys and liver.
 Acts as cofactor for arginase, ICD, LPL.
CHROMIUM
 Has a role in binding in insulin to cells.
 Potentates effects in glucose metabolism
 Deficiency may cause IGT.

12. CALCIUM-Macromineral
Dietary sources:
• Milk, cheese, egg-yolk.
• Beans, nuts, figs, cabbage.
Body distribution:
• Total calcium is 25-35mol (100-170g).
• 99% of total is found in bones
• 0.5% in soft tissue, 0.1% in ECF.
• Normal plasma is 9-11mg/dl.
Calcium in plasma is of 3 types (level 9—11mg/dl):
• Ionized calcium (diffusible) 40% of total (5.5-6.2mg/dl)
• Protein bound calcium (non diffusible) (3.4-4.4mg/dl)
• Complexed calcium with organic acids. (< 0.6mg/dl)
Absorption & excretion:
Total intake 800—1200mg/day
About 40% is absorbed of the Absorption by two mechanisms:
a) Simple diffusion
b) Active transport
Both require active vit.D (calcitriol) which regulate
synthesis of CBP & Ca dependant ATPase

13. CALCIUM CONT.
FACTORS INCREASING ABSORPTION
ACIDIC pH High protein diet
Ca: P ratio vitamin D
young age parathormone (PTH)
FACTORS DECREASING ABSORPTION
Alkaline pH fatty acids
Phytic acid oxalates
High intake P old age
Calcitonin Glucocorticoids
Regulation of calcium:
• PTH by negative feedback
• Active vitamin D
• Calcitonin

14. CALCIUM CONT.
Functions :
• Formation of bones and teeth
• Role in blood coagulation
• Role in neuromuscular
transmission
• Causes excitability of nerves
• Role in muscle contraction
• Normal heart excitability
• Acts as tertiary messenger
• Activates certain enzymes
Hypercalcaemia (> 11mg/dl)
 Hyperparathyroidism
 Malignancies
 Hyperthyroidism
 Hyperalbuminemia
 Renal failure
 Familial hypercalcaemia
Hypocalcaemia (< 8.5mg/dl):
 Hypoparathyroidism
 Hypoalbuminema
 Rickets / osteomalacia
 Acute pancreatitis
 Hypomagnesaemia
 Poor feeding / malabsorption
Tetany (acute or chronic
hypocacaemia)
a) sustained muscle
contraction
b) Jerking movements
/convulsions
c) Carpopedal spasms
/accoucheur’s hands
d) Can occur in severe
alkalosis
e) Death can occur in severe
case
f) Treated by inj.Ca-
gluconate
g) Latent tetany can appear
on stress

15. Phosphorus
1) Total body P is 25mol(700gm)
2) >85% is found in bones
3) Absorption is 90% by PTH & Vit.D3
4) Regulation is by PTH & Vit. D
Function:
a. Formation of bones and teeth
b. Formation of phospholipids
c. Formation of nucleic acid
d. Formation of high energy compounds
e. Formation of coenzymes and
nucleotides
f. Formation of phosphate buffers and
esters
Sulphur- important functions:
 Formation of S-amino acid
 Formation of proteins – Keratin
 Formation of sulpholipids
 Part of enzymes—ACP
 In tertiary structure of proteins
 Co-substrate—S-adenosylmethionine
 S-vitamins i.e biotin,B1, B5,lipoic acid
 Hormones i.e. G-SH, insulin oxytocin
 GAGs i.e. heparin, chondroitin SO4
Magnesium:
 Total in body is about 21gm
 Plasma level 0.8– 1.2mmol/l
 It is Hb of chlorophyll
 Formation of bones and
teeth
 Cofactor for many enzymes
 Lowers neuromuscular
irritability

16. Body Electrolytes:
 Important are Na+, K+, Cl-, HCO3
-
 Maintain osmotic pressure of fluids
 Provide ionic balance for tissues
 Regulation of the pH of body fluids
 Regulation of acid base balance
 Regulate neuromuscular irritability
 Na+ K+ ATPase or Na+ K+ pump
 Indirectly carry CO2 in blood
 NaCl & HCl formation
 Na+ Ca2+ exchange pump for normal heart muscle contraction
 K for normal heart function (diastole)
 Na+ ions help in glucose absorption
Units interconversions :
Mg%= mmol/L x m.wt.
10
Mg%= mEq/L x Eq.wt
10
Mmol/L = mg% x 10
m.wt.
mEql= mg% x 10
Eq.wt.
+++++++++++++++++++++++++++++++++++++++++++++++++++++

17. End of Topic