Cell respiration Definition: The series of chemical reactions in
cells which oxidize food energy (Carbohydrates, proteins, lipids)
into cell energy (ATP) and heat; may occur with or without O2 being
used as the terminal electron acceptor (aerobically or
anaerobically) General equation: Glucose + O2 CO2 + H2O + ATP +
Heat Slide 2 The bottom line of cell respiration is the production
of ATP (cell energy) ATP can be produced in 1 of 3 ways:
1)Substrate-level phosphorylation: Essentially, Food-P + ADP food +
ATP 2) Oxidative phosphorylation: Occurs as NADH2 and FADH2 relay
e-s to an ETC, setting up an electrochemical gradient of H+s which
is relieved by ATPase which uses kinetic energy of proton flow to
form ATP from ADP + Pi 3) Photophosphorylation: during
photosynthesis Slide 3 Substrate-level phosphorylation -occurs
during the rxns of Glycolysis and the Krebs Cycle Slide 4 Oxidative
Phosphorylation: occurs during the rxns of the Electron Transport
Chain along inner membrane (cristae) of the mitochondrion Slide 5
The complete oxidation of food Aerobic respiration Glucose + O2 CO2
+ H2O + energy Equation: Glucose + O2 CO2 + H2O + energy The above
set of reactions occur in 4 distinct steps: 1)Glycolysis splits 6-C
glucose into 2 X 3-C pyruvic acids (pyruvates) 2)Pyruvate oxidation
removes 1 C from each pyruvate to form 2 X 2-C acetyl groups which
may enter the rxns of the Krebs Cycle 3)Krebs Cycle cyclical series
of rxns which break down each of the 2-C acetyl groups into 2 CO2
4)Electron Transport Chain electron carrying coenzymes relay their
e-s to a series of electron carrying proteins to O2 setting up an
electrochemical gradient which is relieved through ATPase which
transforms the kinetic energy of proton flow into ATP formation
Slide 6 During each step of the process, energy is released!! In
Glycolysis: 4 total ATPs are formed (yet, there is only a net gain
of 2 ATPs) and 2 NAD coenzymes are reduced to NADH2 In Pyruvate
oxidation: 2 NADH2s are produced In the Krebs Cycle: 2 ATPs are
formed, 6 NADH2s are produced, and 2 FADH2s In Electron Transport:
32 ATPs are formed as 10 NADH2s and 2 FADH2s are oxidized back to
NAD+ and FAD+ and recycled back to the system and re-used Slide 7 1
2 3 4 ETC Slide 8 The reactions of cell respiration: Glycolysis
Slide 9 The reactions of cell respiration: Pyruvate oxidation Slide
10 The reactions of cell respiration: the Krebs Cycle Slide 11 the
Electron Transport Chain Slide 12 Overview of aerobic respiration
General equation: glucose + O2 CO2 + H2O + energy Glucose is
oxidized (broken down) to form 6 CO2 E-s stripped away from glucose
are relayed to ETC by NAD+ and FAD+ coenzymes and accepted by O2 O2
is the terminal electron acceptor ETC relays e-s and pumps H+s
(protons) [H+] outside of ETC membrane is relieved by ATPase H+s
flow through ATPase ATPase transforms kinetic flow of H+s into bond
between ADP and P
