allianceptp-blog1

[allianceptp-blog1]

How do bacteria breathe?

Bacteria are microscopic single-celled organisms; they have no nucleus or organelles; but like all living things, they breathe, they feed, they adapt to the environment, they communicate, they reproduce and they also breathe, but how do they do it?

Escherichia coli , is a fairly common bacterium that generally inhabits the intestine of some warm-blooded organisms without causing disease, but can also cause infections when its population grows uncontrollably in the host; it is able to survive in bodies of water or the ground; One of the things that allows you to adapt to such different places is that you can breathe using different molecules that help you generate energy.

All living things breathe for chemical energy (mainly in the form of ATP or GTP and in the form of molecules capable of trapping and transferring electrons (e-) such as FADH2 and NADH). Breathing is accomplished through a set of enzyme reactions and oxide-reduction reactions (in which one compound passes electrons (e-) and oxidizes , while another receives electrons and is reduced ).

E. coli can breathe depending on what is available, producing the enzymes it requires. Enzymes are tools made of protein that the cells of living things produce from the information in their DNA.

During respiration, the final electron acceptor is the compound that receives e- at the end of the electron transport chain. Aerobic bacteria breathe O2, anaerobic bacteria breathe using other compounds, and facultative bacteria can use O2 or other compounds.

What happens during aerobic or anaerobic respiration is similar to what happens in a hydroelectric plant, where energy is obtained because the flow of water is converted to mechanical energy and then to electrical energy; in respiration the flow of electrons is converted into useful chemical energy for the various functions of the cell.

Glycolysis is a process to obtain energy, made by aerobic, anaerobic and facultative bacteria; It consists of the breakdown of glucose (a sugar with 6 carbons) in pyruvate (2 molecules with 3 carbons) to obtain energy by removing e- and forming 2 molecules of ATP and two of NADH + H.

The pyruvate dehydrogenase enzyme combines pyruvate with coenzyme-A forming NADH, CO2 and acetyl coenzyme A (acetyl-CoA), which is used in the Krebs Cycle, which is a series of reactions in which 6 enzymes that oxidize acetyl-CoA and They convert it to carbon dioxide, 3 NADH + 3H, and other molecules.

E-trapped in NADHs and protons (H +) produced above are used in oxidative phosphorylation and in proton motive force , which are other cellular ways of obtaining energy. The e-go through a series of reactions known as the electron transport chain , which in the case of aerobic respiration, is composed of: dehydrogenase, quinones, cytochromes and terminal oxidase that passes e- to O2. Simultaneously H + is pumped out of the cell; just as the water accumulated in a dam generates energy when passing through floodgates; the accumulated H + produces energy (in the form of ATP) as it passes through the ATP synthase into the bacteria.

In anaerobic respiration, the e-transport chain is made up of other proteins and enzymes such as: nitrate reductase or fumarate reductase according to the available e-acceptor. Fermentation is another way of obtaining energy in the absence of O2 but it is different from anaerobic respiration.

It is interesting that some microorganisms like E. coli can breathe with any of these processes. In general, aerobic respiration generates more energy than anaerobia and much more than fermentation.

[allianceptp-blog1]

instagram