Catabolic pathways and production of ATP
Fermentation - occurs without O2, is partial degradation of sugars to release energy
Aerobic respiration - uses O2 in breakdown of glucose (or other energy-rich organic compounds) to yield CO2 and H2O and release energy as ATP and heat Of some prokaryotes - doesn’t use O2 as a reactant but it 's a similar process
Cellular respiration - usually used to refer to aerobic process Is exergonic and has a free energy change of -686 kcal/mol of glucose
Redox reactions: oxidation and reduction
Oxidation-reduction - or redox reactions, involve partial or complete transfer of 1 or more electrons from 1 reactant to another
Oxidation - loss of …show more content…
The resulting proton gradient stores potential energy, referred to as the proton-motive force
In mitochondria, exergonic redox reactions produce the H+ gradient that drives the production of ATP
Chloroplasts use light energy to create the proton-motive force used to make ATP by chemiosmosis
Prokaryotes use H+ gradients generated across their plasma membranes to transport molecules, make ATP, and rotate flagella
An accounting of ATP production by cellular respiration
About 36 or 38 ATPs may be produced per glucose molecule oxidized # is only an estimate for 3 reasons: 3 ATPs/NADH and 2 ATPs/FADH2 are rounded off #, the electrons from the NADH produced by glycolysis may be passed across the inner mitochondrial membrane to NAD+ or FAD, depending on the type of shuttle used in cell; and the proton-motive force generated by electron transport chain is also used to power other work in the mitochondrion
The efficiency of respiration in its energy conversions is approximately 40% Rest of energy is released as heat
9.5 Fermentation and anaerobic respiration enable cells to produce ATP without the use of O2
Organisms that generate ATP through anaerobic respiration have an electron transport chain that doesn’t use O2 as the final electron …show more content…
whereas respiration uses O2, via the electron transport chain
Facultative anaerobes, such as yeasts and many bacteria, can make ATP by fermentation or respiration, depending upon the availability of