MAJOR CHEMICAL MAJOR CHEMICAL COMPONENTS COMPONENTS

OF THE LIVING ORGANISMSOF THE LIVING ORGANISMS

Medical BiochemistryMedical BiochemistryMolecular Principles of Structural Organization of CellsMolecular Principles of Structural Organization of Cells

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 elements Macrobiogenic elements (>1%) (>1%) O, C, N, H, Ca, P.O, C, N, H, Ca, P.

– Oligobiogenic elements Oligobiogenic elements (0,1-1%) (0,1-1%) Na, K, Cl, S, Mg, Fe.Na, K, Cl, S, Mg, Fe.

– Microbiogenic elements Microbiogenic 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, is The 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 the There 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

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 lipids Fat tissue cells are rich in lipids – Animal cells are rich in proteins and rather depleted in nucleic acids as Animal cells are rich in proteins and rather depleted in nucleic acids as

compared with plant cellscompared with plant cells

The The waterwater content is different content is different – 40% in plant cells, fat cells40% in plant cells, fat cells– 99% in medusa 99% in medusa

Inorganic compoundsInorganic compounds are in small number but have vital functions in are in small number but have vital functions in the organismthe organism

Cell

Cellular organelles(nuclei, mitochondria,etc)

Enzymes complexes, ribosomes, nucleoli, contractile system

Conjugated proteins:Glycoproteins, Lipoproteins, Phosphoproteins, Nucleoproteins, Metalproteins, Chromoproteins

Polyglucides LipidsProteins

(apoenzymes)Nucleic acids Components of

protein macromolecules(heme, coenzymes)

MonosesFatty acidsAlcohols

(glycerol, sterols, sphingosine

Aminoacids Mononucleotides

Intermediary metabolites

Inorganic compounds

LEVELS OF MOLECULAR ORGANIZATION OF CELL

WATERWATER

Is indispensable for life due to its unique physical and chemical Is 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 organismsContent 45-75% of the total body mass Content 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 specified 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 tissue (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 produced maintained 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 cells Outside 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

WATERWATER

FunctionsFunctions::– DissolutionDissolution and stabilization of biological molecules and ions in the fluids of and stabilization of biological molecules and ions in the fluids of

the organismsthe organisms– Heat balanceHeat balance control - uptake, conservation, distribution and release of heat control - uptake, conservation, distribution and release of heat– TransportTransport – supply of nutrients and excretion of waste products – supply of nutrients and excretion of waste products– Mechanical Mechanical (by hydration) – assistance in maintaining intracellular pressure (by hydration) – assistance in maintaining intracellular pressure

and shape of cellsand shape of cells– Structural Structural – 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– Energetic Energetic (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

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

POPO332-2- 1.41.4 1.41.4 50.050.0

SOSO442-2- 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%

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– Structural Structural – 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 chemical directly binding to enzymes, influencing their activity and rate of the chemical reactions in the cell, or reactions 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+ and and CuCu2+2+; ; oxygen is bound to Feoxygen is bound to Fe2+2+ in the structure of hemoglobin in the structure of hemoglobin

– EnergeticEnergetic – inorganic phosphate in ATP – inorganic phosphate in ATP– Mechanical Mechanical (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)