metabolism in microorganisms

Metabolism in Microorganisms ))
Dr.Baha, H.AL-Amiedi
Ph .D.Microbiology
The processes of breakdown and utilization of food material in bacteria are basically similar to higher organisms ,metabolism can be divided into
Catabolism: is break down of chemical compound into their constituent atoms molecules.
Anabolism : conversion or synthesis of catabolically generated atom into macromolecuoles that constitute physical & chemical make up of cells
All microorganisum seem to have certain fundamental metabolic pathway concerned in the
necessary for the production abasic building blocks .
Energy metabolism
Energy used by bacteria primarily is produced by fermentative and /or respiratory metabolic pathway the expression of genes necessary for the utilization of substrates or for the synthesis of critical compounds :
tightly regulated to satisfy the bacterium needs without consuming unncecessary energy. By breakdown of chemical compounds the main energy - providing chemical compounds are the nutrients carbohydrates lipid and protein
Respiration metabolism.
aerobes obtain energy by a series of coupled oxidation reductions in which the ultimate electron accepter is atmospheric O2 . In this aerobic respiration the carbon and energy source may be complete oxidized to carbon dioxide
and water energy is obtain by a process called oxidative phosphorylation production of energy rich phosphate pound( ATP molecules
&their transfer adenosine diphosphate to form adenosine triphosphate ,glucose C6H12O6 is main respiratory substrate which broken down in living organism to yield energy series enzyme - controlled chemical changes slowly release the potential energy from glucose
ATP can be moved inside the cell and release kinetic energy for various cell activities at the same time forming ADP
C6H12O6 +6O2 ---- 6CO2+6H2O +38 ATP
In aerobically so pyurvate is converted to carbon dioxide via acetylcoenzyme A (acetyl coA) which is the substrate to the Kreb cycle also
Known as the tricarboxylic acid ( TCA) cycle.
It is located in mitocondria the significant of krebs cycle are for production of carbon skeleton for synthesis reactions particularly those leading to synthesis of amino acid and generation of ATP in aerobic condition
other carbohydrate degradation is hexose monophate or pentose or pentose phosphate
pathway and Entner –Dudoroff pathway.
Anerobic respiration
Anaerobic(fermentation) growth occurs by a process in which organic compound (glucose) is not completely oxidized and yields the
end product alcohole lactic acid and others and only a few molecule of ATP for each molecule of glucose oxidized are produced .this process is called substrate level phosphorylation
other fermentation product with diversity of products by the farther metabolism of pyurvate ,depending on the species of bacteria and environmental condition such as PH so the products formed are characteristic of particular species and aid to classification

Anapolism
There are wide differences in ability of cells to carry out the individual biosynthesis of essential manomers, co-enzymes ..etc. from the building blocks produced by catabolism. Others almost completely lack such biosynthesis power within these two extremities there is a wide spectrum of different biosynthesis of essential low molecular weight compounds
The main steps of protein synthesis are:
-2-The activated amino acid are transferred to soluble RNA or tRNA These reactions are catalyzed by amino acetyl RNA synthetase.
-3-mRNA is synthestized on template of chromosomal DNA through the activity of RNA polymerase .
-4-mRNA migreat to Ribosomes to form polysome and serve as template for assembly of amino acids into polypeptide chain. The genetic code is incorporated in the mRNA