Ryann Szakaly
Respiration and Fermentation
Essay: Glycolysis 1
Respiration and Fermentation
● Takes place in the cytosol of the cytoplasm of the mitochondria
● Fermentation
○ A partial degradation of sugars that occurs without O2
○ Usually Anaerobic
● Aerobic Respiration
○ Consumes organic molecules and O2 and yields ATP
○ Anaerobic is similar but consumes compounds other than O2
● Cellular respiration
○ Includes both aerobic and anaerobic processes but is often used to refer to aerobic
respiration
○ C6H12O6 + 6O2 ---> 6CO2 + 6H2O + Energy (ATP + Heat)
Redox
● Redox Reactions
○ Chemical reactions that transfer electrons between reactants
○ Aka Oxidation-reduction reactions
○ Some redox reactions do not transfer electrons but change the electron sharing in
covalent bonds
■ Ex.
● The reaction between methane and O2
● Oxidation
○ A substance loses electrons, is oxidized
● Reduction
○ A substance that gains electrons, is reduced
○ The amount of positive charge is reduced
● Example
○ Na + Cl ---> Na+ + Cl-
○ Na becomes oxidized and loses an electron
○ Cl becomes reduced and gains an electron
● Reducing Agent
○ The electron donor
● Oxidizing Agent
○ The electron acceptor
● NAD+
○ Electrons from organic compounds are usually transferred here
○ A coenzyme
○ Functions as an oxidizing agent during cellular respiration
, ● NADH
○ The reduced form of NAD+
○ Represents stored energy that is trapped to synthesize ATP
○ Passes the electron transport chain
■ Located in the intermembrane
● Electron Transport Chain
○ Electrons are passed to increasingly electronegative carrier molecules down the
chain through a series of redox reactions
○ Electrons transfer to oxygen occurs in a series of energy-releasing steps instead of
one explosive reaction
○ The energy yielded is used to regenerate ATP
○ 1) Uncontrolled Reaction
■ The one-step exergonic reaction of hydrogen with oxygen to form water
releases a large amount of energy in the form of heat and light: an
explosion
○ 2) Cellular Respiration
■ The same reaction occurs in stages: An electron transport chain breaks the
“fall” of electrons in this reaction into a series of smaller steps and stores
some of the released energy in a form that can be used to make ATP. (The
rest of the energy is released as heat.)
● Glycolysis
○ Breaks down glucose into two molecules of pyruvate in the cytosol
○ Pyruvate oxidation and the citric cycle completes the breakdown of glucose in the
mitochondrial matrix
○ Oxydative Phosphorilation
■ Accounts for most of the ATP synthesis and occurs in the inner membrane
of the mitochondria
■ Accounts for almost 90% of the ATP generated by cellular respiration
○ Substrate-Level Phosphorylation
■ A smaller amount of ATP is formed in glycolysis and the citric cycle
■ An enzyme transfers a phosphate group directly from a substrate molecule
to ADP
○ For each molecule of glucose degraded to CO2 and water by respiration, the cell
makes up to 32 molecules of ATP
○ 1) Hexokinase transfers a phosphate group from ATP to glucose, making it more
chemically reactive. The charge on the phosphate also traps the sugar in the cell
○ 2) Glucose 6- phosphate is converted to fructose 6-phosphate
Respiration and Fermentation
Essay: Glycolysis 1
Respiration and Fermentation
● Takes place in the cytosol of the cytoplasm of the mitochondria
● Fermentation
○ A partial degradation of sugars that occurs without O2
○ Usually Anaerobic
● Aerobic Respiration
○ Consumes organic molecules and O2 and yields ATP
○ Anaerobic is similar but consumes compounds other than O2
● Cellular respiration
○ Includes both aerobic and anaerobic processes but is often used to refer to aerobic
respiration
○ C6H12O6 + 6O2 ---> 6CO2 + 6H2O + Energy (ATP + Heat)
Redox
● Redox Reactions
○ Chemical reactions that transfer electrons between reactants
○ Aka Oxidation-reduction reactions
○ Some redox reactions do not transfer electrons but change the electron sharing in
covalent bonds
■ Ex.
● The reaction between methane and O2
● Oxidation
○ A substance loses electrons, is oxidized
● Reduction
○ A substance that gains electrons, is reduced
○ The amount of positive charge is reduced
● Example
○ Na + Cl ---> Na+ + Cl-
○ Na becomes oxidized and loses an electron
○ Cl becomes reduced and gains an electron
● Reducing Agent
○ The electron donor
● Oxidizing Agent
○ The electron acceptor
● NAD+
○ Electrons from organic compounds are usually transferred here
○ A coenzyme
○ Functions as an oxidizing agent during cellular respiration
, ● NADH
○ The reduced form of NAD+
○ Represents stored energy that is trapped to synthesize ATP
○ Passes the electron transport chain
■ Located in the intermembrane
● Electron Transport Chain
○ Electrons are passed to increasingly electronegative carrier molecules down the
chain through a series of redox reactions
○ Electrons transfer to oxygen occurs in a series of energy-releasing steps instead of
one explosive reaction
○ The energy yielded is used to regenerate ATP
○ 1) Uncontrolled Reaction
■ The one-step exergonic reaction of hydrogen with oxygen to form water
releases a large amount of energy in the form of heat and light: an
explosion
○ 2) Cellular Respiration
■ The same reaction occurs in stages: An electron transport chain breaks the
“fall” of electrons in this reaction into a series of smaller steps and stores
some of the released energy in a form that can be used to make ATP. (The
rest of the energy is released as heat.)
● Glycolysis
○ Breaks down glucose into two molecules of pyruvate in the cytosol
○ Pyruvate oxidation and the citric cycle completes the breakdown of glucose in the
mitochondrial matrix
○ Oxydative Phosphorilation
■ Accounts for most of the ATP synthesis and occurs in the inner membrane
of the mitochondria
■ Accounts for almost 90% of the ATP generated by cellular respiration
○ Substrate-Level Phosphorylation
■ A smaller amount of ATP is formed in glycolysis and the citric cycle
■ An enzyme transfers a phosphate group directly from a substrate molecule
to ADP
○ For each molecule of glucose degraded to CO2 and water by respiration, the cell
makes up to 32 molecules of ATP
○ 1) Hexokinase transfers a phosphate group from ATP to glucose, making it more
chemically reactive. The charge on the phosphate also traps the sugar in the cell
○ 2) Glucose 6- phosphate is converted to fructose 6-phosphate
