MAJOR CHEMICAL COMPONENTS OF THE LIVING ORGANISMS Medical Biochemistry Molecular Principles of Structural Organization of Cells CHEMICAL COMPOSITION OF LIVING ORGANISMS In the human organism there are 70 elements of the Periodic Table, which may be divided in four groups: Macrobiogenic elements (>1%) O, C, N, H, Ca, P. Oligobiogenic elements (0,1-1%) Na, K, Cl, S, Mg, Fe. Microbiogenic elements (<0.01%)>50years 45-50%) the content varies depending on the metabolic processes in the specified tissue (10% in the fat tissue, 65-70% in other tissues, 80% in the blood and kidney) maintained at the necessary level through intake (2 liters/day) or produced in the metabolic processes (0.3 liters/day) Distribution: In the cells (intracellular) Outside the cells extracellular fluids (12-16%), blood plasma (5%), lymph (2%) Within closed cavities (intra-cavity water)(1-3%): cerebrospinal fluid, intraocular, pericardial, synovial fluid etc WATER Functions: Dissolution and stabilization of biological molecules and ions in the fluids of the organisms Heat balance control - uptake, conservation, distribution and release of heat Transport – supply of nutrients and excretion of waste products Mechanical (by hydration) – assistance in maintaining intracellular pressure and shape of cells Structural – forming an interlayer between the polar ends of protein and lipids in biological membranes Synthetic (anabolic) – substrate in the synthesis of biological compounds Hydrolytic (catabolic) – substrate in the bond-breaking processes Energetic (electron donating) The cell functions are dependent on: The total amount of intra and extracellular water Hydration of sub-cellular structures Aqueous microenvironment of macromolecules INORGANIC IONS INORGANIC IONS Functions Bioelectric functions – development of potential difference across the cell membrane (neurons, muscle cells) Osmotic functions – control of osmotic and hydro-osmotic pressure Structural – metal ions constituents of macromolecules (proteins, heme) Regulatory – cations exert regulatory action directly binding to enzymes, influencing their activity and rate of the chemical reactions in the cell, or Indirectly, influencing the hormonal regulation Transport – electrons are transported by the cytochromes, enzymes containing Fe2+ or Fe3+ and Cu2+; oxygen is bound to Fe2+ in the structure of hemoglobin Energetic – inorganic phosphate in ATP Mechanical (support) – Ca and P ions are constituents of bones (strength) Synthetic – complex molecules contain I- (hormones), SO42- (ester sulfuric compounds)

1. MAJOR CHEMICALMAJOR CHEMICAL
COMPONENTSCOMPONENTS
OF THE LIVING ORGANISMSOF THE LIVING ORGANISMS
Medical BiochemistryMedical Biochemistry
Molecular Principles of Structural Organization of CellsMolecular Principles of Structural Organization of Cells

2. CHEMICAL COMPOSITION OF LIVING ORGANISMSCHEMICAL COMPOSITION OF LIVING ORGANISMS
In the human organism there are 70 elements of the Periodic Table,In the human organism there are 70 elements of the Periodic Table,
which may be divided in four groups:which may be divided in four groups:
– Macrobiogenic elementsMacrobiogenic elements (>1%)(>1%) O, C, N, H, Ca, P.O, C, N, H, Ca, P.
– Oligobiogenic elementsOligobiogenic elements (0,1-1%)(0,1-1%) Na, K, Cl, S, Mg, Fe.Na, K, Cl, S, Mg, Fe.
– Microbiogenic elementsMicrobiogenic elements (<0.01%)(<0.01%) Zn, Mn, Co, Cu, F, B, I.Zn, Mn, Co, Cu, F, B, I.
– Ultramicrobiogenic elements (10Ultramicrobiogenic elements (10-4-4
-10-10-6-6
%)%) Li, Al, Si, Cd, Cr, Ni.Li, Al, Si, Cd, Cr, Ni.
They are constituents of organic and inorganic compounds.They are constituents of organic and inorganic compounds.
Exception:Exception:
The oxygen molecular form, besides being bound to hemoglobin or myoglobin, isThe oxygen molecular form, besides being bound to hemoglobin or myoglobin, is
dissolved in biological fluids.dissolved in biological fluids.
There are other gases (nitrogen, inert gases) which are partly dissolved in theThere are other gases (nitrogen, inert gases) which are partly dissolved in the
biological liquids but do not take part in the biochemical processesbiological liquids but do not take part in the biochemical processes

3. CHEMICAL COMPOSITION OF LIVING ORGANISMSCHEMICAL COMPOSITION OF LIVING ORGANISMS
Organic compoundsOrganic compounds. Different cells can vary in the content of. Different cells can vary in the content of
proteins, nucleic acids, lipids, polysaccharides, for example:proteins, nucleic acids, lipids, polysaccharides, for example:
– Liver and muscle cells are rich in polysaccharidesLiver and muscle cells are rich in polysaccharides
– Fat tissue cells are rich in lipidsFat tissue cells are rich in lipids
– Animal cells are rich in proteins and rather depleted in nucleic acids asAnimal cells are rich in proteins and rather depleted in nucleic acids as
compared with plant cellscompared with plant cells
TheThe waterwater content is differentcontent is different
– 40% in plant cells, fat cells40% in plant cells, fat cells
– 99% in medusa99% in medusa
Inorganic compoundsInorganic compounds are in small number but have vital functions inare in small number but have vital functions in
the organismthe organism

4. Cell
Cellular organelles
(nuclei, mitochondria,etc)
Enzymes complexes, ribosomes, nucleoli, contractile system
Conjugated proteins:
Glycoproteins, Lipoproteins, Phosphoproteins, Nucleoproteins, Metalproteins, Chromoproteins
Polyglucides Lipids
Proteins
(apoenzymes)
Nucleic acids Components of
protein macromolecules
(heme, coenzymes)
Monoses
Fatty acids
Alcohols
(glycerol, sterols, sphingosine
Aminoacids Mononucleotides
Intermediary metabolites
Inorganic compounds
LEVELS OF MOLECULAR ORGANIZATION OF CELL

5. WATERWATER
Is indispensable for life due to its unique physical and chemicalIs indispensable for life due to its unique physical and chemical
properties and importance for biological activity of living organismsproperties and importance for biological activity of living organisms
Content 45-75% of the total body massContent 45-75% of the total body mass
– depends on age (new born 75%, >50years 45-50%)depends on age (new born 75%, >50years 45-50%)
– the content varies depending on the metabolic processes in the specifiedthe content varies depending on the metabolic processes in the specified
tissue (10% in the fat tissue, 65-70% in other tissues, 80% in the bloodtissue (10% in the fat tissue, 65-70% in other tissues, 80% in the blood
and kidney)and kidney)
– maintained at the necessary level through intake (2 liters/day) or producedmaintained at the necessary level through intake (2 liters/day) or produced
in the metabolic processes (0.3 liters/day)in the metabolic processes (0.3 liters/day)
Distribution:Distribution:
– In the cells (intracellular)In the cells (intracellular)
– Outside the cellsOutside the cells
extracellular fluids (12-16%),extracellular fluids (12-16%),
blood plasma (5%),blood plasma (5%),
lymph (2%)lymph (2%)
– Within closed cavities (intra-cavity water)(1-3%): cerebrospinal fluid,Within closed cavities (intra-cavity water)(1-3%): cerebrospinal fluid,
intraocular, pericardial, synovial fluid etcintraocular, pericardial, synovial fluid etc

6. WATERWATER
FunctionsFunctions::
– DissolutionDissolution and stabilization of biological molecules and ions in the fluids ofand stabilization of biological molecules and ions in the fluids of
the organismsthe organisms
– Heat balanceHeat balance control - uptake, conservation, distribution and release of heatcontrol - uptake, conservation, distribution and release of heat
– TransportTransport – supply of nutrients and excretion of waste products– supply of nutrients and excretion of waste products
– MechanicalMechanical (by hydration) – assistance in maintaining intracellular pressure(by hydration) – assistance in maintaining intracellular pressure
and shape of cellsand shape of cells
– StructuralStructural – forming an interlayer between the polar ends of protein and lipids– forming an interlayer between the polar ends of protein and lipids
in biological membranesin biological membranes
– Synthetic (Synthetic (anabolicanabolic) – substrate in the synthesis of biological compounds) – substrate in the synthesis of biological compounds
– Hydrolytic (Hydrolytic (cataboliccatabolic) – substrate in the bond-breaking processes) – substrate in the bond-breaking processes
– EnergeticEnergetic (electron donating)(electron donating)
The cell functions are dependent on:The cell functions are dependent on:
– The total amount of intra and extracellular waterThe total amount of intra and extracellular water
– Hydration of sub-cellular structuresHydration of sub-cellular structures
– Aqueous microenvironment of macromoleculesAqueous microenvironment of macromolecules

7. INORGANIC IONSINORGANIC IONS
IonsIons Plasma (%)Plasma (%) Extracellular (%)Extracellular (%) Intracellular (%)Intracellular (%)
CationsCations NaNa++
92.292.2 94.094.0 7.57.5
KK++
3.03.0 2.72.7 75.075.0
CaCa2+2+
3.03.0 2.02.0 2.52.5
MgMg2+2+
1.31.3 1.31.3 15.015.0
TotalTotal 100%100% 100%100% 100%100%
AnionsAnions ClCl--
69.069.0 76.076.0 7.57.5
HCOHCO33
--
17.017.0 19.319.3 5.05.0
POPO33
2-2-
1.41.4 1.41.4 50.050.0
SOSO44
2-2-
0.60.6 0.70.7 10.010.0
organicorganic 2.02.0 2.02.0 2.52.5
proteinprotein 10.010.0 0.60.6 25.025.0
TotalTotal 100%100% 100%100% 100%100%

8. INORGANIC IONSINORGANIC IONS
FunctionsFunctions
– Bioelectric functionsBioelectric functions – development of potential difference across the cell– development of potential difference across the cell
membrane (neurons, muscle cells)membrane (neurons, muscle cells)
– Osmotic functionsOsmotic functions – control of osmotic and hydro-osmotic pressure– control of osmotic and hydro-osmotic pressure
– StructuralStructural – metal ions constituents of macromolecules (proteins, heme)– metal ions constituents of macromolecules (proteins, heme)
– RegulatoryRegulatory – cations exert regulatory action– cations exert regulatory action
directly binding to enzymes, influencing their activity and rate of the chemicaldirectly binding to enzymes, influencing their activity and rate of the chemical
reactions in the cell, orreactions in the cell, or
Indirectly, influencing the hormonal regulationIndirectly, influencing the hormonal regulation
– Transport –Transport –
electrons are transported by the cytochromes, enzymes containing Feelectrons are transported by the cytochromes, enzymes containing Fe2+2+
or Feor Fe3+3+
andand
CuCu2+2+
;;
oxygen is bound to Feoxygen is bound to Fe2+2+
in the structure of hemoglobinin the structure of hemoglobin
– EnergeticEnergetic – inorganic phosphate in ATP– inorganic phosphate in ATP
– MechanicalMechanical (support) – Ca and P ions are constituents of bones (strength)(support) – Ca and P ions are constituents of bones (strength)
– SyntheticSynthetic – complex molecules contain I– complex molecules contain I--
(hormones), SO(hormones), SO44
2-2-
(ester sulfuric(ester sulfuric
compounds)compounds)