Ppt bioinorganic chemistry by dr.seema pattanshetti

Details of bioinorganic elements , functions, structures discussed.

1. Bio inorganic Chemistry
Essential and trace elements in biological process,
metalporephyrins w.r.t. haemoglobin and chlorophyll
(structure and function), biological role of Na, K, Fe and
Zn.
PRESENTED BY:
Dr. SeemaS. Pattanshetti
Assistant Professor of Chemistry
S.NijalingappaSugar Institute,
College of B.Sc. (Sugar Science &
Technology), Belagavi

2. Introduction:
•Inorganicreagentsandreactionshaveplayedanimportantroleinthe
formationanddevelopmentoforganiclifemolecularontheearthfrom
verybeginningoflifeonearth.
•Inorganicchemistryisinvolvedinstructureandfunctionsofalllife
formspresentonearth.
•Bioinorganicchemistry:
•Itistheinorganicchemistryoflivingorganisms.Itisconcernedwith
thefunctionsofallmetallicandmostnon-metallicelementsin
biology.
•Thesemetalionsplayinavastnumberofwidelydifferingbiological
processes.

3. Introduction:
•It stretches from chemical physics to clinical medicine.
•The bioinorganic chemistry is about structure, function, mechanism
and dynamics of biologically relevant metal complexes and metal
containing proteins.

4. HISTORY An Interdisciplinary Research Field
Bulk inorganic elements long been
known to be essential
Blood known to contain iron since
17th century
Need for Zinc, 1896
Bioinorganic chemistry developed
as a field after 1960
First inorganic biochemistry
symposium in 1970
SBIC (Society of Biological Inorganic
Chemistry) formed in 1995

5. Functions of Metals in Mammals
•Structure Hard material –bone and teeth
•Cell membranes
•DNA and RNA structure
•Protein, including enzyme conformation
•Charge carriers : Na+, K+, Ca
2+
•Electron transfer (Redox reactions) : Fe, Cu, Mn, Mo, Ni, Co
•Metabolism : Degradation of organic molecules
•Activation of small molecules : O
2, CO
2

6. Bio Inorganic chemistry
•Thesebioinorganicmaterialsmainlypresentontheearth.Atmosphere
containsCo
2,N
2,H
2Oasmaincomponentsandtraceamountofgases
likeH
2,CO.H
2O,NH
3andCH
4fromvolcanicexhalations,cosmic
rays,radioactivityetc.
•Manyinorganicelementsplaysanimportantroleinphysiological
contentsomeare–Fe,Cu,Znarepresentmainlyinallorganisms.
•Otherelementsareintraces.i.e.Hydrogen,Lithium,Sodium,
Manganese,Calcium,potassiumMn,Fe,Co,Ni,As,Br,Sn,Bi,Pt,
Au,Ag,W,Cl,Si,P,S,Moetc.Thesearebioelementsfromperiodic
table

7. Bio Inorganic chemistry
Study of Inorganic elements in the living systems Na
11
22.98
K
19
39.09 Ca
20
40.08
Mg
12
24.31
Sodium potassium pump
(1/5
th
of all the ATP used)
Hemoglobin Vit B12 Hemocyanin Carbonic anhydrase
Myoglobin Carboxypeptidase
Cytochromes
FerredoxinCu
29
63.55
Zn
30
65.38
Fe
26
55.85
Co
27
58.94

8. 1. Regulatory Action Sodium potassium channels and pump
Na, K Nerve signals and impulses, action potential
muscle contraction
2. Structural Role Calcium in bones, teeth
Ca, Mg provide strength and rigidity
3. Electron transfer agents Cytochromes: redox intermediates
Fe
2+
/Fe
3+
membrane-bound proteins that
contain heme groups and carry out electron
transport in Oxidative phosphorylation
4. Metalloenzymes Carbonic anhydrase, Carboxypeptidase
Zn biocatalysts, CO
2to HCO
3

,protein digestion
5. Oxygen carriers and storageHemoglobin, Myoglobin, Hemocyanin
Fe, Cu 18 times more energy from glucose in
presence of O
2
6. Metallo coenzymes Vitamin B 12
Co biomethylation
Important roles metalsplay in biochemistry

9. ESSENTIAL AND TRACE ELEMENTS IN BIOLOGICAL
PROCESSES :
•Therearesomeessentialbioinorganicmaterialsinthatsomeofthem
areusedintraceamountastraceelementsinmetabolismofliving
organisms.
•Theseareclassifiedintoessentialandnonessentialelements
accordingtotheiractioninthebiologicalsystem.
•1.EssentialElements
•2.Non-essentialelements
•3.ToxicElements.

10. 1.Essential Elements
•Theseareveryessential/necessaryforlifeprocesses.
Ex:
•C,H,N,O–Bulkelements
•Na,K,P,S,Ca,Cl,Fe,Mg–Macronutrientsorrequiredinrelatively
largeamounts.
•Mn,Co,Cu,Ni,V,Cr,Mo,F,Al,Pb,Sn,Zn,Si–Micronutrients(trace
elements).

11. •2.Non-Essential Elements
•These are not essential. In their absences also living organisms May
serve the same function.
•Ex: Al, Sr, Ba, Sn etc.,
•3.Toxic Elements:
•These elements disturb the natural functions of biological system. Our
human body is made up of 99.9% of just 11 elements disturb the
natural functions of biological system.
•Our human body is made up of 99.9% of just 11 elements in that 4
are hydrogen, oxygen, carbon, nitrogen with 62.8%, 25.4%, 9.4% and
1.4% respectively.
•Ex: Pb, Cd, Hg etc.,

12. Deficiency diseases
•(Methyl mercury) minamata discote (loss of vision, Paralysis, made
weakness)
•Cd-Cd poisoning causes –Kindney failures, bone softening’s –by
mining companies to rivers. Itai –Itai disease (Japan)
•Lead–lead based points, dust, cigarette smoke, household, Industrial
dust all human body can damage.

13. METALLOPORPHYRINS:
•Metalloporphyrineareimportantbiochemicalcompounds.
•Theseisnatureareconjugatedtoproteinsandformmanyimportantbiologiccompounds.
•Ex:Ironcontaininghaemoglobinmoleculeswhichbindtooxygenandactsasoxygen
transportersinvertebrates.
•Generallytheseporphyrinscombinedwithmetallikecopper,zinc,iron,magnesium,
silveretc.
•Ex:Haemoglobin.Itisapigmentpresentinredbloodcells.
•Theseabsorbtheintensivecolourbandsinvisibleregionandduetothisthesearedeeply
colouredporphyrins–Greekword–Purple.

14. STRUCTURE AND FUNCTIONS OF
HAEMOGLOBIN:
•Haemoglobinisaglobularhaemoglobinproteininredbloodcells(RBC)whichtransportsoxygen
fromthelungstotheperipheraltissuesofthebodymainlyitisresponsiblefortheredcolourofthe
bloodcells.
•Hemeisaniron(II)complexofprotoporphyrinIXligand.Haemoglobincarriesoxygenefficiently
fromlungstothetissuesinthebody.Italsoaidsthetransportinghydrogenionsandcarbondioxide
backtothelungs.
•Itcomposedof4-subunitseachcontainingaCo-factorknownashemegroupthatinducesaniron
atomcentre.
•Haemoglobintightlybindsoxygenfromthelungs,carrieritfromthelungstotheperipheraltissues
ofthebody,afterunloadingoxygenattheperipheraltissues,itbindscarbondioxidesandreturnsit
tothelungstoexhaled.Itcontains2proteinsununits;2ά&2.

15. STRUCTURE AND FUNCTIONS OF
HAEMOGLOBIN contd..
•Abnormalitiescausesavarietyofdisorderslikesicklecellanaemia(RBCbecome
misshapenandbrokendown;RBCconvertsinsickleshape,cellsdie.,early,leavinga
shortageofhealthyredbloodcellsandcanblockbloodflowcausingpainorsickle
cellcrisis.
•Thalassemia(Itishereditaryhaemolyticdiseasecausedbyfaultyhaemoglobin
synthesis,widespreadmainlyinMediterranean,AfricanandAsiancounties.
•ItismainlycausedbymutationsintheDNAofcellthatmakeshaemoglobin;this
maypausefromparentstochildren’s).

16. STRUCTURE OF HEME :
•Str:Itcontains4polypeptideunits;2and2chainseachwith141and146aminoacidrespectively.
•AhememoleculeisacyclicmoleculethatconsistsofnitrogencarbonandhydrogenatomswithaFe
+2
ionlocatedintheCentre.
•Inamolecule,4-nitrogenmoleculesholdtheironinthecentre.Thisironinformsthebondingwitha
histidinesidechainfromoneofthesubunits,whichformsthepocket.
•Theseironionbondstohistidine87inchainandhistidine92in-Chain.
•Herebothand87,92arepartofFhelixineachsubmit.Thetotalmolarmassofhaemoglobinis
about64,500.

17. STRUCTURE OF HEME :

18. STRUCTURE OF HEME :
•TheO
2doesnotoxidizehaemoglobinconsideringtheredoxpotentials
forthereductionofO
2andOxidationofFe
+2
.Thereversiblebinding
ofO
2inhaemoglobinisduetotheporphyrinringsystemand
hydrophobicblockingoflargeprotein(globin).Hereaporphyrinring
systemwithCo-ordinatediron(hemegroup).
•Here“globin”fromhaemoglobinrefersindividualproteinsubunits.
Subunitofthiseach,containsmainlyandheliceswithnobetastands.
Eachsubunitfoldsinto8-helicalsegmentswhichformsapocket
thatholdstheheme.

19. Protoporphyrin IX and Heme
15 different ways to arrange the substituents around the porphyrin. Only one
isomer protopophyrin IX is found in the living system. Porphyrins are planar
and aromatic

20. Proteins –consists of different amino acids in a specific sequence connected by the peptide
bond –

21. Hemoglobin molecule:

22. Inorganic Prosthetic group of three well known oxygen carriers
Present in
Vertebrates
Present in
molluscs
Present in some sea
worms

23. Can the prosthetic unit part of a metalloprotein perform its normal function
without the protein unit around it ?Fe
2+
Free Heme
+ O
2
Fe
2+
O
O
Fe
2+
O
O
Fe
2+
+ 2Fe
4+
O
Fe
4+
O Fe
2+
+
Fe
3+
O
Fe
3+
Reversible binding of O
2is possible on when protein
unit is present around the heme unit

24. STRUCTURE AND FUNCTIONS OF CHLOROPHYLL:
•ItwasfirstisolatedbyJosephbienaimeCaventouandPierreJosephPelletierin
1817.
•Itisamoleculepresentingreenplants,absorbssunlightandusesitsenergytosynthesize
CarbohydratesfromCO
2andwater,thisprocessisknownasphotosynthesisorlightdriven
processisthebaseforalllifeprocessesofplants.
•ItisderivedfromGreekworkChlorosmeansgreenandphyllonmeansleaf.Itallowsplantsto
absorbenergyfromlightanditconvertslightenergyintofood(Carbohydrates)intheplant.
•Photosynthesis Reaction:
•6CO
2+6H
2OC
6H
12O
6+ 6O
2( in pr. Of light energy)
•Chlorophyll absorbs light strongly in the blue portion of electromagnetic
spectrum followed by red portion.

25. STRUCTURE OF CHLOROPHYLL

26. STRUCTURE OF CHLOROPHYLL
•TheprincipalphotoreceptorinthePhotosynthesisreactionischlorophyll.Mainlyitis
foundinthechloroplastsofgreenplants[ItisthesiteofPhotosynthesisinalgaeand
higherplants]thesearemainlylocatedinmesophyllcellsofthestemandleavesit
containsmainlymembrane,strong,grana
•Itisregionforgreencoloroftheplants.ThebasicstructureofChlorophyllmolecule
isaporphyrinringco-ordinatedtoacentralatom.Groupfunctioninhaemoglobin
exceptthatinhemecentralatomisiron,whereasinchlorophyllitismagnesium.Itis
Macrocyclictetrapyrrole,derivedbiosyntheticallyfromprotoporphyrinIX,differs
fromhemein4-majorrespects.

27. STRUCTURE OF CHLOROPHYLL

28. BIOLOGICAL ROLE OF SOME METAL IONS:
•Metal ions play an important role in human beings system. The
concentration of metalions, their control is generally exercised by
some biological complexing agents. And the deficiency or excess of
metal ions causes disorder, which leads to various diseases.

29. Biological Role of Na:
•Sodium is the one of the most predominant extracellular cation in the
animals and man. Generally human body has about 105 grms of Na in
adults and about 24% is located in the bone and 65% in cellular level
water. The sodium ion equilibrium is maintained by kidney (electro
cycle balances).
•Sodium mainly founds in fluids occurs in cells. These sodium ions
have some main functions like:

30. Biological Role of Na:
•Itcontrolstheosmoticpressureandequilibriuminacidbasesystem.
•Thereionshaveimportantroleinmetabolismonwaterinthebody.
•Inbloodstream93%ofNaions(bases)found.
•TheyhavemainspecificroleintheabsorptionofCarbohydrates.
•Theyalsohasaneffectonmuscleirritability.
•TheseNaionsintermofNaClplaysanveryimportantroleinhuman
body,NaCl(salt)isthemaindietarysourceneededtohumanbody.
TheexcessintakeofNamaycauseelevationinbloodpressure(hyper
tension/highB.P)andreducedNaintakecausesandcontrolsthehigh
bloodpressure.

31. Role of Na
+
:
•Itisanexcellentfluid.
•Inhumanbodyitplaysanimportantkeyroleinregulationofbloodvolume,B.P.Osmoticpressureand
maintainsconstantpH.
•Itbalancesthepressure/Osmoticpressuresoitisalsoknownas“Sodiumpump”ofthehumanbody.
•Itplaysamainroleintheequilibriumofacidsandbases.
•Proteins,Aminoacid,NucleicacidsareconfirmedbythisNa.
•NervesystemimpulsioncanbeelectricallybalancedbytheseNa
+
ions.
•IthasmainroleinfunctioningofneuronsandOsmoregulationbetweencellsandextracellularfluids.
•Insufficientsodiuminourbloodmaycausehyponatremia.Lackofsodiummaycausekidneydiseasesan
enlargementinheartmusclesandheadacheOsteoporosis,stomachcanceretc.,Toomuchsodiumcanalso
affecttheappearance/vision.

32. Biological Role of K:
•K is found in most animal and vegetable foods. An adult human has
approximately 140 grms of K in intra cellular water as cation. Since
muscle contains most of the body’s intra cellular water, it also
contains K.
•Like sodium potassium has stimulating effect on muscle irritability.
•K required for protein synthesis, glycogen preparation and metabolic
break down of glucose.
•Potassium is one of the major cation present in intra cellular fluid and
it regulates intra cellular Osmatic pressure, acid base balances.
•

33. Biological Role of K+:
•As a major component for protein synthesis and RNA replication.
•Secretion of gastric acid is from K.
•Acts enzyme activators.
•Act as Trans membrane potential.
•It helps to regulate fluid balance, muscle contractors and nerve
signals.

34. Biological Role of Fe:
•Ironisanessentialcomponentpresentinhaemoglobinandmyoglobin.Ourbody
containsabout4-5grmsofFe60-70%ofFepresentinhaemoglobininredblood
all.
•Ironisessentialforvariousenzymaticsystemlikecytochroma,eatalses,
peroxidises,succinicdehydragenaseetc.
•Ironisessentialforoxygenandelectrontransportwithinthebody.RoleofFe,Cu,
Mo.
•Electrontransfer.
•Oxidation-reductionofproteins.
•Nitrogenfixation

35. Biological Role of Fe:
•Redox reactions of enzymes
•Proteins with oxygen.
•
•3-5% is in muscle myoglobin.
•12-15% is in protein in cellular level.
•0.004% is bound to the serum transport protein
•to 0.2% is in respiratory enzymes
•

36. Deficiency Diseases:
•May cause anaemia because of red cells of blood with low level of
haemoglobin than the normal level.
•Acute iron poisoning leads to vomiting shock, collapse, pallor and
coma.
•Higher iron deposition yellowish of skin/unhealthy pale appearance in
tissues and organs may also affect the body is known as siderosis.

37. Biological Role of Zn:
•Zinc is an active component or cofactor for many enzymatic reactions.
Mainly in lipid, protein, carbohydrates metabolism, several
peptidases, oxalacetic decarboxylase.
•In wound healing this Zn plays an important role and for hormonal
activities like insulin, glucagen corticotrophin, FSH and LH Zn plays a
vital role.
•More than 80 metalloenzymes in living organisms includes the Zn for
Carbonic an hydras (CO
2transportation in blood and for secretion of
HCl acid in stomach), pan creatic carboxypeptidase, tryptophan
desmolase, alkaline phosphatise etc.

38. Deficiency of Zn:
•In human beings, mainly in an adult body zinc is present as 1.5 –3.0
grms in liver and bone.
•Zn efficiency found in an in heriated form in many infants is known as
acrodermatitis enteropathica.
•
•Deficiency may cause behavioural disturbances.
•Diarrhoea, hair loss, skin rashes, weight loss etc.

39. Role of Zinc:
•As a lewis acid [Electron pair acceptor (H
+
)] H
+
-chat can accept a pair
of non-bonding electrons].
•As metallo enzymes.
•Structure promoters for proteins.

40. Glycolysis + Oxidative phosphorylation: How food is converted into energyGlucose + 36 ADP + 36 Pi + 36 H
+
+ 6 O
2 6 CO
2 + 36 ATP + 42 H
2O
Glucose gives 18 times more energy when oxidized
ATP + H
2O ADP + Pi + H
+
+ energyG
0
= - 7.3 kCal/mole
DifferentformsofCytochromes(except
CytochromeP-450)areinvolvedinthe
electrontransferprocessleadingtoATP
synthesisandconversionofO
2toH
2O
See youtube video ‘cellular respiration ( electron transfer chain)’
ATP : Universal currency for energy
in living systems

41. 

141 Amino acid
146 Amino acid
Mb153 Amino acid Hemoglobin Hb
Four units of Hb
See youtube video ‘Oxygen Transport’
3 major types of
Hb
Hb A (Adult)
Hb F ( Fetal)
Hb S (Sickle cell)
Hb is not an exact tetramer of Mb

42. N
N
N
N
FeFe
DEOXYMYOGLOBIN OXYMYOGLOBIN
N
N
H
Protein
N
N
H
Protein
N
N
H
Protein
N
N
H
Protein
Proximal
histidine
Distal
histidine
O
O
Fe
2+
t
2g
4
e
g
2
, HIgh spin, radius 92 pm Fe
3+
t
2g
5
e
g
0
, Low spin, radius 75 pm
Paramagnetic Diamagnetic
Fe 42 pm outside porphyrin plane Fe fits inside the porphyrin plane Basics of oxygenation remains same for Hb and Mb. But there
are some differences in the way the four units get oxygenated.
This begins with pulling of the proximal histidine when Fe gets
inside the plane of the porphyrin ring upon oxygen binding

43. Hemoglobin S (Sickle Cell Anaemia)
Sickle-cell anaemia is caused by a mutation in the β-globin chain of haemoglobin, causing a hydrophilic
amino acid glutamic acid to be replaced with the hydrophobic amino acid valine.
In areas where malaria is a problem, people's chances of survival actually increase if they carry sickle-cell trait (Carrier).
The malaria parasite has a complex life cycle and spends part of it in red blood cells. In a carrier, the presence of the
malaria parasite causes the red blood cells with defective haemoglobin to rupture prematurely, making the plasmodium
unable to reproduce. The polymerization of Hb S affects the ability of the parasite to digest Hb.
See youtube videos ‘Sickle Cell’ and ‘Sickle cell disease’

44. QUESTIONS:
•2 marks questions:
•Define bioinorganic molecules.
•Mention any 2 biological functions of Na
+
and K
+
.
•Mention biological function of Iron.
•Name essential and trace elements in biological process.
•What are metalloporphyrin? Give an example.
•5 marks questions:
•Explain structure and biological function of Haemoglobin.
•Write a note on biological functions of metal ions in the human body.
•Explain structure and biological functions of chlorophyll.