Respiration
Respiration occurs in animals and plant cells. For example yeast -> RP9
The main organelle it takes place in is the mitochondria
Glucose + Oxygen → Carbon dioxide + water + ATP
C6H12O6 + 6O2 → 6CO2 + 6H2O
Oxidation and Reduction
Oxidation means the release of a hydrogen molecule that then goes onto reduce another molecule
An example is TP is oxidised which releases the Hydrogen ion from TP. This hydrogen ion is
used to reduce NAD to form NADH
Reduction means the addition of a hydrogen ion to a molecule
Mitochondria
ATP synthase
Cristae
Intermembrane
space
Aerobic respiration
Stages of aerobic respiration
, 1. Glycolysis
2. Link reaction
3. Krebs cycle
4. Oxidative phosphorylation
Glycolysis – split glucose into 2 pyruvate
Takes place in the cytoplasm
Glucose (6C) is phosphorylated to become phosphorylated glucose (6C)
o 2 ATP is hydrolysed to produce 2 ADP and 2 Pi (phosphate molecules)
o Reaction is endothermic – ATP is used up
Phosphorylated glucose is phosphorylated and splits into 2 Triose Phosphate (3C) (TP)
o 2 ATP is hydrolysed to produce 2 ADP and 2 Pi (phosphate molecules)
o Reaction is endothermic – ATP is used up
TP is oxidised into 2 pyruvate (3C)
o Oxidation of TP causes the release of Hydrogen which is used to reduce NAD to
NADH
o 2 NAD is reduced to NADH
o 4 ATP is made
Net gain of ATP is 2
Outcome
+ 2 ATP (net gain)
+ 2 NADH
+ 2 pyruvate (3c)
Link reaction – convert pyruvate to acetyl CoA
Takes place in the matrix
Pyruvate passes through the mitochondria by active transport
Pyruvate is oxidised into acetate
o NAD is reduced to NADH
o Removal of 1 CO2
Acetate combines with co-enzyme A to produce Acetyl CoA (2C)
Outcome
- 1 CO2
+ 1 NADH
Acetyl CoA (2C)
NO ATP made
Krebs cycle – reduce co-enzyme NAD and FAD
Takes place in the matrix
Acetyl CoA (2C) reacts with a 4C molecule (oxaloacetate)
Co-enzyme A is released
This forms citrate (6C)
Citrate enters the krebs cycle where a series of oxidation and reduction reactions happen
Respiration occurs in animals and plant cells. For example yeast -> RP9
The main organelle it takes place in is the mitochondria
Glucose + Oxygen → Carbon dioxide + water + ATP
C6H12O6 + 6O2 → 6CO2 + 6H2O
Oxidation and Reduction
Oxidation means the release of a hydrogen molecule that then goes onto reduce another molecule
An example is TP is oxidised which releases the Hydrogen ion from TP. This hydrogen ion is
used to reduce NAD to form NADH
Reduction means the addition of a hydrogen ion to a molecule
Mitochondria
ATP synthase
Cristae
Intermembrane
space
Aerobic respiration
Stages of aerobic respiration
, 1. Glycolysis
2. Link reaction
3. Krebs cycle
4. Oxidative phosphorylation
Glycolysis – split glucose into 2 pyruvate
Takes place in the cytoplasm
Glucose (6C) is phosphorylated to become phosphorylated glucose (6C)
o 2 ATP is hydrolysed to produce 2 ADP and 2 Pi (phosphate molecules)
o Reaction is endothermic – ATP is used up
Phosphorylated glucose is phosphorylated and splits into 2 Triose Phosphate (3C) (TP)
o 2 ATP is hydrolysed to produce 2 ADP and 2 Pi (phosphate molecules)
o Reaction is endothermic – ATP is used up
TP is oxidised into 2 pyruvate (3C)
o Oxidation of TP causes the release of Hydrogen which is used to reduce NAD to
NADH
o 2 NAD is reduced to NADH
o 4 ATP is made
Net gain of ATP is 2
Outcome
+ 2 ATP (net gain)
+ 2 NADH
+ 2 pyruvate (3c)
Link reaction – convert pyruvate to acetyl CoA
Takes place in the matrix
Pyruvate passes through the mitochondria by active transport
Pyruvate is oxidised into acetate
o NAD is reduced to NADH
o Removal of 1 CO2
Acetate combines with co-enzyme A to produce Acetyl CoA (2C)
Outcome
- 1 CO2
+ 1 NADH
Acetyl CoA (2C)
NO ATP made
Krebs cycle – reduce co-enzyme NAD and FAD
Takes place in the matrix
Acetyl CoA (2C) reacts with a 4C molecule (oxaloacetate)
Co-enzyme A is released
This forms citrate (6C)
Citrate enters the krebs cycle where a series of oxidation and reduction reactions happen
