C6H12O6 + 6 O2 → 6 H2O + 6 CO2
Cellular Respiration
• Cellular Respiration- process by which
the mitochondria breaks down food
molecules (glucose) to make ATP
C6H12O6 + 6 O2 → 6 CO2 + 6 H2O
• 2 helper molecules: NAD+ and FAD+
• All organisms perform some type of
cellular respiration
• Aerobic Respiration produces 36 ATP
molecules
– Aerobic processes are the most efficient
• 3 stages: glycolysis, the citric acid
cycle, the electron transport chain
Cellular Respiration
Aerobic Respiration
• Stage 1 - Glycolysis
– series of chemical reactions
– occurs in the cytoplasm
– anaerobic (no oxygen is needed
for this stage)
– breaks glucose into 2 pyruvic
acid molecules
Cellular Respiration
Aerobic
Respiration
Stage 1 –
Glycolysis
Cellular Respiration
Aerobic Respiration
• Pyruvic acid is
converted to acetyl
coenzyme A (acetyl
CoA) then enters the
Krebs Cycle
Cellular Respiration
Aerobic Respiration
• Stage 2 – The Citric Acid Cycle
(TCA Cycle) or Krebs Cycle
– acetyl CoA is used
– aerobic process
– occurs in the mitochondria
Cellular Respiration
Aerobic
Respiration
Stage 2 – The Citric
Acid Cycle (TCA
Cycle) or Krebs
Cycle
Cellular Respiration
Aerobic Respiration
• Stage 3 - The Electron Transport Chain
(ETC)
– occurs on the cristae of the
mitochondria
– helper molecules (NADH & FADH2)
pass energized electrons down a
series of proteins embedded in the
membrane – the electrons slowly
release energy – the energy is used
to make ATP
– the H electron eventually bonds with
oxygen to form water
Cellular Respiration
Aerobic
Respiration
Stage 3 –
The Electron
Transport Chain
(ETC)
The Electron
Transport Chain
Cellular Respiration
Vs.
Photosynthesis
• both use electron carriers (helper molecules)
• both use a cycle of chemical reactions
• both use an electron transport chain to form
ATP
Photosynthesis– produces glucose and oxygen
– uses carbon dioxide and water
Cellular Respiration– uses oxygen to break down glucose
– produces carbon dioxide and water
The Reactions Are Opposites!!!!
Anaerobic
Cellular Respiration
Lactic Acid Fermentation
• glycolysis produces pyruvic acid
which cannot go on to the Krebs
Cycle because oxygen is not
available - So, it becomes lactic
acid
• the body does this when oxygen is
not available; it causes muscle
fatigue
Anaerobic
Cellular Respiration
Lactic Acid Fermentation
Anaerobic
Cellular Respiration
Alcoholic Fermentation
• yeast cells produce carbon dioxide
and ethyl alcohol