CELLULAR RESPIRATION All living things in the world including plants require energy in order to function. This energy is obtained from the food we eat. The cells break down the energy stored in the food through a unique system known as cellular respiration. In plain language, cellular respiration means the procedure through which the food is broken down by the cells of living beings in order to produce the energy which is in the form of ATP molecules (also known as the Adenosine Tri Phosphate molecules). Plants use a part of this ATP energy during photosynthesis for producing sugar. The sugars are then broken down during cellular respiration. This cycle is continued again and again as long as the plant lives.
GLYCOLISIS Glycolysis (it literally means glucose degradation) is a metabolic pathway which changes glucose C6H12O6 into pyruvate CH3COCOO + H. The free energy which is generated in this process is utilized to make high energy compounds namely ATP (adenosine triphophate) and NADH (reduced nicotinamide adenine dinucleotide). This occurs in the cytoplasm. Was found out by Gustav Embden and Otto Meyerhof.
ANAEROBIC RESPIRATION AN Anaerobic organism is called an ANAEROBE One way of doing this is to just get the pyruvate to do oxidation; in this procedure the pyruvate gets converted in to lactate (this is the conjugate base of lactic acid) in a process which is called lactic acid fermentation. This process can be represented in a word equation as: pyruvate + NADH + H -> lactate + NAD
ANAEROBIC RESPIRATION Some organisms like yeast turn NADH to NAD in a reaction called as ethanol fermentation. In the reaction the pyruvate is turned first into acetaldehyde and CO2, after this into ethanol. The lactic acid fermentation and ethanol fermentation can happen in the lack of oxygen presence. The anaerobic fermentation lets a lot of single celled organisms to use glycolysis as their only source of energy. From the two examples above regarding the fermentation, NADH is oxidized by sending 2 electrons to pyruvate. But anaerobic bacteria use a big range of compounds as the terminal electron acceptors in the process of cellular respiration
Anaerobic respiration forhumans In general in humans it is the muscle tissue that respires anaerobically normally during exercise, at which time the body cannot intake the required oxygen for the cells to respire. This clearly indicates that enough energy is not made and the muscles require more energy. So they achieve it in the absence of oxygen. But when they have stopped exercising, commonly an oxygen debt has been created, because of the large amount of lactic acid inside the muscles. It is because of this fact the humans breath heavily after exercising to negate the oxygen debt.