It’s the only chemical in the body that can be directly used as
energy. Other forms of chemical energy need to be converted into ATP before
they can be used. Another important point is
that ATP is recyclable. If the molecule was used up after each reaction, it
wouldn’t be practical for metabolism.
dismutase is an enzyme that
alternately catalyzes the dismutation (or
partitioning) of the superoxide(O2?) radical into either ordinary molecular oxygen (O2) or hydrogen peroxide (H2O2). Superoxide is produced as a by-product of oxygen
metabolism and, if not regulated, causes many types of cell damage. This is why catalase is important for the
activity of this enzyme as catalyzes the decomposition of hydrogen
peroxide to water and oxygen.
The final stage of cellular respiration is the
electron transport chain (ETC). The ETC is a series of molecules embedded in
the mitochondrial membrane. In the absence
of oxygen the ETC stops working and no ATP is
generated. Cyanide prevents oxygen from
binding to the final molecule in the electron transport chain.
a digestive enzyme that is used in the citric acid cycle. Its main function is
to catalyze the oxidative decarboxylation of isocitrate into alpha-ketoglutarate. Deficiency disrupts
the mitochondrial redox balance, resulting in oxidative damage to mitochondria
The ATP generated in this process is made by substrate-level
phosphorylation, which does not
Fermentation is less efficient at using the energy from glucose: only 2 ATP are produced per glucose, compared to the 38 ATP per glucose nominally produced by aerobic respiration.
The presence of fumarate afforded consistently
larger cell crops in growth studies with glucose and other energy sources. On a
molar growth-yield basis, anaerobically grown, glucose-fumarate cultures were
equivalent to aerobically grown, glucose cultures. The reduction of fumarate by
That increase is accompanied by a concomitant
decrease in insulin
secretion, because the actions of
insulin, which are aimed at increasing the storage of glucose in the
form of glycogen in cells, oppose the action of glucagon. Following secretion, glucagon travels to the
liver, where it stimulates glycogenolysis.