Chapter 7: Cellular Respiration
Redox Reaction: Reactions in which one species is reduced and another is oxidized.
❖ Reduction: Gaining e-
❖ Oxidation: Losing e-
● The transfer of electrons between molecules is important because most of the
energy stored in atoms and used to fuel cell functions is in the forms of
high-energy electrons
● Electron carriers: NADH. NADPH, FADH2
● ATP has adenosine, three phosphate groups, nucleotide
○ Dephosphorylation: Releasing a phosphate group also releases energy.
○ Phosphorylation: The addition of the phosphate.
○ Oxidative phosphorylation occurs during ETC, it involves oxygen.
1. Glycolysis is the first step of cellular respiration, no oxygen needed
● Break down of a glucose molecule into 2-3 carbon molecules (pyruvates)
● Takes place in the cytoplasm, needs “2 ATP investment)
● Extracts energy from the molecules and stores it in the form of ATP and
NADH, the reduced form of NAD.
2. Pyruvate will be transformed into an acetyl group that will be picked up and
activated by a carrier compounds called coenzyme A (CoA) The resulting compound is
called acetyl CoA
3. Citric cycle ( also known as Kreb cycle)
4. Oxidative phosphorylation: Process in which ATP is formed as a result of the transfer
of electrons from NADH or FADH2 to O2 by a series of electron carriers
● Produces ATP, NAD+, FAH
ETC: H+ are pumped outside, creating concentration gradient, oxygen is the final
electron acceptor
Complexes I,II, III, IV are used during ETC to create concentration gradient.
Chemiosmosis: the free energy from the series of redox reactions is used to pump
hydrogen ions (protons) across the membrane.
● Electrons are pumped by ATP synthase through phosphorylation
● Used to generate 90% of the ATP
● The number of ATP molecules generated from the catabolism of glucose varies.
For example, the number of hydrogen ions that the electron transport chain
complexed can pump through the membrane varies between species.
Redox Reaction: Reactions in which one species is reduced and another is oxidized.
❖ Reduction: Gaining e-
❖ Oxidation: Losing e-
● The transfer of electrons between molecules is important because most of the
energy stored in atoms and used to fuel cell functions is in the forms of
high-energy electrons
● Electron carriers: NADH. NADPH, FADH2
● ATP has adenosine, three phosphate groups, nucleotide
○ Dephosphorylation: Releasing a phosphate group also releases energy.
○ Phosphorylation: The addition of the phosphate.
○ Oxidative phosphorylation occurs during ETC, it involves oxygen.
1. Glycolysis is the first step of cellular respiration, no oxygen needed
● Break down of a glucose molecule into 2-3 carbon molecules (pyruvates)
● Takes place in the cytoplasm, needs “2 ATP investment)
● Extracts energy from the molecules and stores it in the form of ATP and
NADH, the reduced form of NAD.
2. Pyruvate will be transformed into an acetyl group that will be picked up and
activated by a carrier compounds called coenzyme A (CoA) The resulting compound is
called acetyl CoA
3. Citric cycle ( also known as Kreb cycle)
4. Oxidative phosphorylation: Process in which ATP is formed as a result of the transfer
of electrons from NADH or FADH2 to O2 by a series of electron carriers
● Produces ATP, NAD+, FAH
ETC: H+ are pumped outside, creating concentration gradient, oxygen is the final
electron acceptor
Complexes I,II, III, IV are used during ETC to create concentration gradient.
Chemiosmosis: the free energy from the series of redox reactions is used to pump
hydrogen ions (protons) across the membrane.
● Electrons are pumped by ATP synthase through phosphorylation
● Used to generate 90% of the ATP
● The number of ATP molecules generated from the catabolism of glucose varies.
For example, the number of hydrogen ions that the electron transport chain
complexed can pump through the membrane varies between species.
