Please enable JavaScript.
Coggle requires JavaScript to display documents.
Cellular Respiration and Fermentation - Coggle Diagram
Cellular Respiration and Fermentation
Cellular respiration
equation - Glucose + 6 Oxygen → 6 CO2 + 6 Water + 30-32 ATP
mitochondria - powerhouse of the cell, site of most ATP production in eukaryotes
ATP - energy currency of the cell, used for endergonic processes
reactants - glucose (C6H12O6) and Oxygen (O2)
products - carbon Dioxide (CO2), Water (H2O), and ATP
redox reactions - cellular respiration is a series of reduction-oxidation reactions
glucose is oxidized to CO2 (loses electrons/hydrogens)
oxygen is reduced to Water (gains electrons/hydrogens)
oxygen's role: emphasized as the terminal electron acceptor, crucial for the ETC to function, and its connection to breathing
weight loss mechanism: explains how the majority of weight loss occurs through exhaling CO2, a product of glucose and fat oxidation
phases of cellular respiration: detailed breakdown of Glycolysis, Pyruvate Oxidation, Citric Acid Cycle (Krebs/TCA Cycle), and Oxidative Phosphorylation
ATP production: distinction between oxidative phosphorylation (28 ATP) and substrate-level phosphorylation (4 ATP)
electron carriers: role of NAD+ and FAD in transporting electrons/hydrogens
aerobic vs. anaerobic respiration: key difference lies in the terminal electron acceptor (oxygen vs. other electronegative molecules).
fermentation: explained as a process occurring in the absence of sufficient oxygen where only glycolysis functions, leading to lactic acid or alcohol production.
limiting factor in fermentation: the need to regenerate NAD+ for glycolysis to continue
story-like explanation: the topic is explained in a narrative fashion to enhance understanding
backwards approach: oxidative phosphorylation (Phase 3) is explained first, followed by earlier phases
ATP synthase: explained as a rotary motor powered by proton diffusion (chemiosmosis) and proton motive force (PMF)
Mitochondrial
outer Membrane: encloses the mitochondrion.
inner Membrane: highly folded (cristae), site of ATP synthase and ETC.
intermembrane space: Space between outer and inner membranes, where protons accumulate
matrix: innermost compartment, where pyruvate oxidation and citric acid cycle occur
ATP synthase
transmembrane enzyme complex in the inner mitochondrial membrane
combines ADP and inorganic phosphate (Pi) to make ATP
produces 28 of the 30-32 net ATP
top part spins, acting as a rotary motor
Chemiosmosis
diffusion of protons (H+) across the inner membrane from high concentration (intermembrane space) to low concentration (matrix)
powers ATP synthase
Proton motive force (PMF)
the force exerted by the electrochemical gradient of protons
drives the spinning of ATP synthase
electron transport chain (ETC)
composed of protein complexes (Complex I, II, III, IV) in the inner mitochondrial membrane
function: actively pumps protons from the matrix to the intermembrane space
power source: spontaneous flow of electrons through the complexes
electron flow: electrons move from low electronegativity to high electronegativity
terminal electron acceptor (TEA): oxygen (O2) picks up electrons at Complex IV, forming water (H2O)
importance of oxygen: without oxygen, electrons back up, and the ETC shuts down
Mitochondria vs. Chloroplasts
Similarities
Both have electron transport chains and ATP synthases embedded in membranes.
Both generate a proton gradient for chemiosmosis.
diff
ETC/ATP Synthase Location
Mitochondria: Inner membrane.
Chloroplasts: thylakoid membrane.
high Proton concentration Area
mitochondria: intermembrane space.
chloroplasts: thylakoid space.
ATP Synthesis Location:
mitochondria: mitochondrial matrix.
chloroplasts: stroma.
energy source
mitochondria: chemical energy (glucose).
chloroplasts: light energy.
Electron carriers
NAD+ (nicotinamide adenine dinucletide)
oxidized form
picks up 2 electrons and 1 proton to become NADH
NADH delivers electrons to Complex I of the ETC
FAD (flavin adenine dinucleotide)
oxidized form
picks up 2 electrons and 2 protons to become FADH2
FADH2 delivers electrons to Complex II of the ETC
role: transport hydrogens (electrons and protons) from glucose/fats to the ETC.
glycolysis (phase 1)
location: cytosol (cytoplasm)
input: 1 glucose molecule
investment Phase: uses 2 ATP to phosphorylate glucose
Pay phase
glucose is split into two 3-carbon
pyruvate molecules.
produces 4 ATP via substrate-level phosphorylation.
produces 2 NADH.
net Output: 2 pyruvate, 2 Net ATP, 2 NADH
NADH destination: ETC (Complex I)
Citric acid cycle (kerbs cycle/ tca cycle (phase 2)
location: mitochondrial matrix.]
input: 2 acetyl-CoA molecules (from pyruvate oxidation)
cycle mechanism: Acetyl-CoA combines with oxaloacetate (regenerated at the end of the cycle)
output (per glucose, 2 turns)
4 CO2 (all carbons from original glucose are now released)
6 NADH
2 FADH2
2 ATP (via substrate-level phosphorylation)
NADH/FADH2 destination: ETC (Complex I and II)
eukaryotes: 30 Net ATP
glycolysis: 2 ATP (substrate-level)
citric acid cycle: 2 ATP (substrate-level)
oxidative phosphorylation: 28 ATP
cost: 2 ATP to transport pyruvate into mitochondria
prokaryotes: 32 net ATP (no mitochondrial transport cost)
aerobic respiration vs. anaerobic respiration vs. fermentation
aerobic respiration: requires oxygen as the terminal electron acceptor
involves all phases: glycolysis, pyruvate oxidation, citric acid cycle, oxidative phosphorylation
humans perform aerobic respiration
anaerobic respiration:
does NOT require oxygen
uses an alternative electronegative molecule (e.g., sulfate, nitrate) as the terminal electron acceptor
involves all phases of cellular respiration
performed by some prokaryotes; humans are NOT capable
fermentation:
occurs when there is insufficient terminal electron acceptor (oxygen for humans)
only glycolysis operates
produces only 2 Net ATP per glucose
key Problem: regeneration of NAD+ is crucial for glycolysis to continue
latic acid fermentation (in animals)
pyruvate is reduced by NADH to form lactic acid
regenerates NAD+ for glycolysis
occurs in muscles during strenuous exercise
alcohol fermentation (in yeast)
pyruvate is first converted to acetaldehyde, releasing CO2
acetaldehyde is then reduced by NADH to form ethanol
regenerates NAD+ for glycolysis
used in brewing alcohol
Oxidative Phosphorylation
ATP Synthase
transmembrane enzyme complex in the inner mitochondrial membrane.
combines ADP and inorganic phosphate (Pi) to make ATP.
produces 28 of the 30-32 net ATP.
Top part spins, acting as a rotary motor.
chemiosmosis
diffusion of protons (H+) across the inner membrane from high concentration (iddntermembrane space) to low concentration (matrix).
powers ATP synthase.
power motive force (PMF)
the force exerted by the electrochemical gradient of protons.
drives the spinning of ATP synthase.
electron transport chain
composed of protein complexes (complex I, II, III, IV) in the inner mitochondrial membrane
function: actively pumps protons from the matrix to the intermembrane space.
power Source: spontaneous flow of electrons through the complexes
electron flow: electrons move from low electronegativity to high electronegativite
terminal electron acceptor (TEA): Oxygen (O2) picks up electrons at complex IV, forming water (H2O)
importance of oxygen: without oxygen, electrons back up, and the ETC shuts down
electron carriers
NAD+ (Nicotinamide Adenine Dinucleotide):
oxidized form
picks up 2 electrons and 1 proton to become NADH
NADH delivers electrons to Complex I of the ETC
FAD (Flavin Adenine Dinucleotide):
oxidized form
picks up 2 electrons and 2 protons to become FADH2
FADH2 delivers electrons to Complex II of the ETC
role: transport hydrogens (electrons and protons) from glucose/fats to the ETC
Glycolysis (Phase 1)
location: cytosol (cytoplasm)
input: 1 glucose molecule
investment phase: uses 2 ATP to phosphorylate glucose
payoff phase
glucose is split into two 3-carbon pyruvate molecules
produces 4 ATP via substrate-level phosphorylation
produces 2 NADH
net Output: 2 Pyruvate, 2 Net ATP, 2 NADH
NADH Destination: ETC (Complex I)
Pyruvate Oxidation (Phase 1.5)
location: mitochondrial matrix
input: 2 pyruvate molecules (from glycolysis)
process (per pyruvate):
oxidized: 1 CO2 released
1 NAD+ reduced to NADH.Remaining 2-carbon molecule combines with Coenzyme A to form Acetyl-CoA
output (per glucose): 2 acetyl-CoA, 2 CO2, 2 NADH.
NADH destination: ETC (Complex I).
Citric Acid Cycle (Krebs Cycle / TCA Cycle) (Phase 2)
location: mitochondrial matrix.
input: 2 Acetyl-CoA molecules (from pyruvate oxidation)
cycle mechanism: acetyl-CoA combines with oxaloacetate (regenerated at the end of the cycle)
output (per glucose, 2 turns):4 CO2 (all carbons from original glucose are now released)
6 NADH
2 FADH2
2 ATP (via substrate-level phosphorylation)
NADH/FADH2 destination: ETC (Complex I and II, respectively)
ATP yield summary
eukaryotes: 30 Net ATP
glycolysis: 2 ATP (substrate-level)
citric acid cycle: 2 ATP (substrate-level)
oxidative Phosphorylation: 28 ATP
cost: 2 ATP to transport pyruvate into mitochondria.Prokaryotes:
32 Net ATP (no mitochondrial transport cost)