Cellular Respiration
Biology
Cellular Respiration
• Releases chemical energy from sugars and other
carbon-based molecules to make ATP when oxygen
is present
Cellular Respiration
• Releases chemical energy from sugars and other
carbon-based molecules to make ATP when oxygen
is present
• Aerobic: needs oxygen
Cellular Respiration
• Releases chemical energy from sugars and other
carbon-based molecules to make ATP when oxygen
is present
• Aerobic: needs oxygen
• Occurs in the mitochondria
Glycolysis
• Occurs before cellular respiration begins
Glycolysis
• Occurs before cellular respiration begins
• Breaks glucose down into two 3-carbon molecules
and 2 molecules of ATP
Glycolysis
• Occurs before cellular respiration begins
• Breaks glucose down into two 3-carbon molecules
and 2 molecules of ATP
• Process is anaerobic, meaning it does not require
oxygen
Glycolysis
• Occurs before cellular respiration begins
• Breaks glucose down into two 3-carbon molecules
and 2 molecules of ATP
• Process is anaerobic, meaning it does not require
oxygen
• Occurs in the cytoplasm of the cell
Glycolysis
• Occurs before cellular respiration begins
• Breaks glucose down into two 3-carbon molecules
and 2 molecules of ATP
• Process is anaerobic, meaning it does not require
oxygen
• Occurs in the cytoplasm of the cell
• Products of glycolysis are used to make more ATP
in the mitochondria
Cellular Respiration
• “Opposite” of photosynthesis
Cellular Respiration
• “Opposite” of photosynthesis
• Photosynthesis is used to make molecules to store
energy (glucose)
Cellular Respiration
• “Opposite” of photosynthesis
• Photosynthesis is used to make molecules to store
energy (glucose)
• Cellular respiration uses glucose to release chemical
energy
Cellular Respiration
• “Opposite” of photosynthesis
• Photosynthesis is used to make molecules to store
energy (glucose)
• Cellular respiration uses glucose to release chemical
energy
• Structure of mitochondria and chloroplast are
similar in that they both have membrane spaces
where the reactions occur
Cellular Respiration
• “Opposite” of
photosynthesis
• Photosynthesis is used to
make molecules to store
energy (glucose)
• Cellular respiration uses
glucose to release chemical
energy
• Structure of mitochondria
and chloroplast are similar
in that they both have
membrane spaces where the
reactions occur
Cellular Respiration
• Two main stages:
Cellular Respiration
• Two main stages:
• Krebs Cycle
Cellular Respiration
• Two main stages:
• Krebs Cycle
• Electron Transport Chain
Cellular Respiration
• Two main stages:
• Krebs Cycle
• Three carbon molecules from glycolysis are broken down
• Electron Transport Chain
Cellular Respiration
• Two main stages:
• Krebs Cycle
• Three carbon molecules from glycolysis are broken down
• Small number of ATP and other energy molecules made
• Electron Transport Chain
Cellular Respiration
• Two main stages:
• Krebs Cycle
• Three carbon molecules from glycolysis are broken down
• Small number of ATP and other energy molecules made
• Carbon dioxide is produced as a waste product
• Electron Transport
Cellular Respiration
• Two main stages:
• Krebs Cycle
• Three carbon molecules from glycolysis are broken down
• Small number of ATP and other energy molecules made
• Carbon dioxide is produced as a waste product
• Electron Transport Chain
• Energy is transferred to proteins in inner membrane of the
mitchondria
Cellular Respiration
• Two main stages:
• Krebs Cycle
• Three carbon molecules from glycolysis are broken down
• Small number of ATP and other energy molecules made
• Carbon dioxide is produced as a waste product
• Electron Transport Chain
• Energy is transferred to proteins in inner membrane of the
mitochondria
• Large number of ATP made
Cellular Respiration
• Two main stages:
• Krebs Cycle
• Three carbon molecules from glycolysis are broken down
• Small number of ATP and other energy molecules made
• Carbon dioxide is produced as a waste product
• Electron Transport Chain
• Energy is transferred to proteins in inner membrane of the
mitochondria
• Large number of ATP made
• Water is made with the addition of oxygen
• Waste product along with heat
Overall Products
• Per glucose molecule:
Overall Products
• Per glucose molecule:
• 2 ATP from glycolysis
Overall Products
• Per glucose molecule:
• 2 ATP from glycolysis
• 34-36 ATP from cellular respiration
Overall Products
• Per glucose molecule:
• 2 ATP from glycolysis
• 34-36 ATP from cellular respiration
• Carbon dioxide
Overall Products
• Per glucose molecule:
•
•
•
•
2 ATP from glycolysis
34-36 ATP from cellular respiration
Carbon dioxide
Water
Overall Products
• Per glucose molecule:
•
•
•
•
•
2 ATP from glycolysis
34-36 ATP from cellular respiration
Carbon dioxide
Water
Heat
Overall Products
• Per glucose molecule:
•
•
•
•
•
2 ATP from glycolysis
34-36 ATP from cellular respiration
Carbon dioxide
Water
Heat
• C6H12O6 + 6O2  6CO2 + 6H2O
Cellular Respiration:
In Detail
Glycolysis
• Takes place in the cytoplasm
Glycolysis
• Takes place in the cytoplasm
• Does not require oxygen (anaerobic)
Glycolysis
• Takes place in the cytoplasm
• Does not require oxygen (anaerobic)
• Creates 2 ATP and 2 pyruvate
Glycolysis
• Start with glucose
Glucose
Glycolysis
• Start with glucose
• 1 ATP is used to break glucose into two 3-carbon
molecules
Glucose
Glycolysis
• Start with glucose
• 2 ATP is used to break glucose into two 3-carbon
molecules (Glyceraldehyde 3-phosphate or G3P)
2 ATP
Glucose
2 ADP
2 G3P
Glycolysis
• Start with glucose
• 2 ATP is used to break glucose into two 3-carbon molecules
(Glyceraldehyde 3-phosphate or G3P)
• Electrons from G3P is used to make 2 NADH from NAD+
2 ATP
Glucose
2 ADP
2 G3P
Glycolysis
• Start with glucose
• 2 ATP is used to break glucose into two 3-carbon molecules
(Glyceraldehyde 3-phosphate or G3P)
• Electrons from G3P is used to make 2 NADH from NAD+
2 ATP
Glucose
2 ADP
2 G3P
2 NAD+ 2 NADH
Glycolysis
• Start with glucose
• 2 ATP is used to break glucose into two 3-carbon molecules
(Glyceraldehyde 3-phosphate or G3P)
• Electrons from G3P is used to make 2 NADH from NAD+
• G3P converted to pyruvate and 4 ATP are made
2 ATP
Glucose
2 ADP
2 G3P
2 NAD+ 2 NADH
Glycolysis
• Start with glucose
• 2 ATP is used to break glucose into two 3-carbon molecules
(Glyceraldehyde 3-phosphate or G3P)
• Electrons from G3P is used to make 2 NADH from NAD+
• G3P converted to pyruvate and 4 ATP are made
2 ATP
Glucose
2 ADP
2 G3P
4 ADP 4 ATP
2 NAD+ 2 NADH
Pyruvate
Glycolysis Products
• Net product of 2 ATP (4 ATP made – 2 ATP used)
• 2 molecules of pyruvate
• 2 molecules of NADH (electron carrier)
Krebs Cycle
• Occurs in the matrix of the mitochondria
Krebs Cycle
• Occurs in the matrix of the mitochondria
• Also called the Citric Acid Cycle, as that is its first
product
Krebs Cycle
• Pyruvate broken down into
a 2 carbon molecule and
CO2
• NAD+ is turned into
NADH
• An enzyme call Coenzyme
A bonds to the 2 carbon
molecule to produce AcetylCoA, which enter the cycle
Krebs Cycle
• Acetyl-CoA is added to a
4-carbon molecule already
in the cycle
• CoA is released back to the
beginning of the cycle
• This forms citric acid
Krebs Cycle
• Citric Acid is broken down
into a 5-carbon molecule
• CO2 is released
• An NAD+ is turned into
NADH
Krebs Cycle
• 5-carbon molecule is broken
down
• CO2 is released
• NAD+ is made into NADH
• A molecule of ATP is
formed
• 4-carbon molecule is
formed
Krebs Cycle
• 4-carbon molecule is
rearranged
• A FAD is turned into
FADH2
• NAD+ becomes NADH
• 4-carbon molecule is
recycled back into the cycle
Krebs Cycle Products
• 3 molecules of CO2
• 1 molecule of ATP
• 4 molecules of NADH
• 1 molecule of FADH2
Krebs Cycle Products
• 3 molecules of CO2
• 1 molecule of ATP
• 4 molecules of NADH
• 1 molecule of FADH2
Move on to the
electron transport
chain
Electron Transport Chain
• Takes place across the inner membrane of the
mitochondria
Electron Transport Chain
• Takes place across the inner membrane of the
mitochondria
• Proteins within the membrane use the energy from
NADH and FADH2 to pump ions against a
concentration gradient to make ATP
Electron Transport Chain
Electrons are removed from NADH and FADH2
Releases H+ ions within the mitochondrial matrix
2 molecules of NADH and one of FADH2
Electron Transport Chain
High energy electrons provide the energy for trans-membrane proteins
Proteins pump H+ ions into the inter-membrane space of mitochondria
Creates a chemiosmotic gradient
Electron Transport Chain
Oxygen picks up H+ ions and electrons to form water
Electron Transport Chain
H+ ions are pumped through ATP synthase to make ATP
For every 2 electrons approximately 3 ATP are made
Products of Cellular
Respiration
• Carbon Dioxide
• Water
• ~38 ATP per glucose molecule
• 2 from glycolysis
• 2 from Krebs cycle
• 34 from electron transport chain
Photosynthesis and Cellular
Respiration
Photosynthesis
Cellular Respiration
Organelle For Process
chloroplast
mitochondria
Reactants
CO2 and H2O
C6H12O6 and O2
Electron Transport
Chain
proteins within
thylakoid membrane
proteins within inner
mitochondrial
membrane
Cycle of Chemical
Reactions
Calvin Cycle in stroma
of chloroplasts builds
sugar molecules
Krebs cycle in matrix of
mitochondria breaks
down carbon-based
molecules
Products
C6H12O6 and O2
CO2 and H2O