Respiration, water-carbon dioxide reaction

These studies demonstrate the general mechanism of synchronization of biochemical systems, which I expect to be operative in even more complex systems, such as the mitochondrial respiration or the periodic activity of the slime mold Dictyostelium discoideum. As shown in a number of laboratories under suitable conditions mitochondrial respiration can break into self-sustained oscillations of ATP and ADP, NADH, cytochromes, and oxygen uptake as well as various ion transport and proton transport functions. It is important to note that mitochondrial respiration and oxidative phosphorylation under conditions of oscillations is open for the source, namely, oxygen, as well as with respect to a number of sink reactions producing water, carbon dioxide, and heat. 

The ready reversibility of this reaction is essential to the role that qumones play in cellular respiration the process by which an organism uses molecular oxygen to convert Its food to carbon dioxide water and energy Electrons are not transferred directly from the substrate molecule to oxygen but instead are transferred by way of an electron trans port chain involving a succession of oxidation-reduction reactions A key component of this electron transport chain is the substance known as ubiquinone or coenzyme Q... 

The fixation of carbon dioxide to form hexose, the dark reactions of photosynthesis, requires considerable energy. The overall stoichiometry of this process (Eq. 22.3) involves 12 NADPH and 18 ATP. To generate 12 equivalents of NADPH necessitates the consumption of 48 Einsteins of light, minimally 170 kj each. However, if the preceding ratio of l ATP per NADPH were correct, insufficient ATP for COg fixation would be produced. Six additional Einsteins would provide the necessary two additional ATP. Prom 54 Einsteins, or 9180 kJ, one mole of hexose would be synthesized. The standard free energy change, AG°, for hexose formation from carbon dioxide and water (the exact reverse of cellular respiration) is +2870 kj/mol. 

Respiration The process by which organisms break down nutrients for energy oxygen is needed for the reactions, and carbon dioxide and water are produced. 

The respiration reaction is, basically, the opposite of the photosynthesis reaction. During respiration, glucose within the cells reacts with oxygen to produce carbon dioxide, water, and energy. 

All living cells produce energy by a process called cellular respiration. It involves a series of metabolic pathways, each with several reactions. Most commonly, cellular respiration takes place in the presence of oxygen and involves the breakdown of glucose to carbon dioxide and water, coupled with the production of ATP. 

The reactions of the electron transport chain yield most of the ATP produced by cellular respiration. These reactions take place in tiny structures within the cell called mitochondria and involve the transport of electrons. The end result of the electron transport chain is the production of 32 molecules of ATP. Thus, the total breakdown of one glucose molecule to carbon dioxide and water yields 36 molecules of ATP. 

O respiration the biochemical reaction in living cells that produces energy from the reaction ol glucose and oxygen to produce carbon dioxide and water... 

Algae seem to offer better opportunities for study than land plants because of their simpler structure and intimate thermal contact with a large excess of water. The matter of respiration is troublesome, for, in the dark, the living cells consume oxygen and liberate carbon dioxide in direct opposition to the photosynthetic reaction. It has been assumed that respiration is the same in the light as in the dark, but this assumption is of doubtful validity. Further investigation of respiration is necessary. 

From a biological perspective, the key events of this cycle are the complementary reactions of respiration and photosynthesis. Respiration takes carbohydrates and oxygen and combines them to produce carbon dioxide, water, and energy. Photosynthesis takes carbon dioxide and water and produces carbohydrates and oxygen. The outputs of respiration are the inputs of photosynthesis, and the outputs of photosynthesis are the inputs of respiration, as shown in Figure 7.4. 

Biological activities, such as photosynthesis and respiration, physical phenomena, such as natural or induced turbulence with concomitant aeration, and above all processes such as the precipitation and dissolution of CaC03 and of other minerals influence pH regulation through their respective abilities to decrease and increase the concentration of dissolved carbon dioxide. Besides photosynthesis and respiration, other biologically mediated reactions affect the H" ion concentrations of natural waters. Oxygenation reactions often lead to a decrease in pH, whereas processes such as denitrification and sulfate reduction tend to increase pH. 

When fresh-cut logs are converted quickly into large piles of chips, the living cells of the sapwood, together with the fungi and bacteria mentioned above, rapidly convert the stored food reserves into carbon dioxide (CO2), water, and heat see Reaction 1 for respiration) (45). If this metabolic heat is not dissipated, the pile becomes hot, and under conditions of very poor ventilation can lead to spontaneous combustion (46). For all of these reasons, fresh-cut sap-wood must be considered to be alive and, therefore, must be handled as a perishable raw material. 

The third stage, respiration, is a complex system of reactions in which molecules provided by glycolysis are oxidized. Oxygen is consumed, carbon dioxide and water are formed, and energy is produced. 

---