Chapter 12: Energy and Respiration (Oxidative Phosphorylation)
Oxidative Phosphorylation
From glycolysis to Kreb’s cycle, only substrate-level phosphorylation has produced ATP, when a
phosphate group is transferred from an intermediate to ADP.
Oxidative phosphorylation, the final stage of aerobic respiration, generates ATP by using the flow of
protons through ATP synthase.
what does substrate level phosphorylation mean?
Substrate-level phosphorylation is a key process in cellular metabolism where a phosphate
group is directly transferred from a substrate molecule to ADP (adenosine diphosphate) to form
ATP (adenosine triphosphate). This process occurs during glycolysis and the citric acid cycle.
Where oxidative phosphorylation occurs:
Oxidative phosphorylation occurs across the inner mitochondrial membrane of the cristae.
The cristae are the inner folded membranes in mitochondria where the enzymes and
proteins involved in oxidative phosphorylation are located.
Some of these proteins are involved in the electron transfer chain: a series of electron carrier
molecules in the inner mitochondrial membrane that release energy in stages.
Releasing energy in stages allows more energy to be harvested for the benefit of the organism,
rather than being released as heat.
, Reactants of oxidative phosphorylation:
Reduced NAD
Reduced FAD
Oxygen
ADP and inorganic phosphate
Products of oxidative phosphorylation:
NAD
FAD
Water
ATP
Oxidative phosphorylation has several key steps:
1. Reduced NAD and reduced FAD release hydrogen, transferring protons (H +) and
electrons (e-) into the mitochondrial matrix.
2. High-energy electrons are passed to an electron carrier from reduced NAD and
reduced FAD.
3. The electrons are passed along a series of electron carrier molecules in the electron
transport chain embedded in the inner mitochondrial membrane, releasing energy
as they are transferred.
Oxidative Phosphorylation
From glycolysis to Kreb’s cycle, only substrate-level phosphorylation has produced ATP, when a
phosphate group is transferred from an intermediate to ADP.
Oxidative phosphorylation, the final stage of aerobic respiration, generates ATP by using the flow of
protons through ATP synthase.
what does substrate level phosphorylation mean?
Substrate-level phosphorylation is a key process in cellular metabolism where a phosphate
group is directly transferred from a substrate molecule to ADP (adenosine diphosphate) to form
ATP (adenosine triphosphate). This process occurs during glycolysis and the citric acid cycle.
Where oxidative phosphorylation occurs:
Oxidative phosphorylation occurs across the inner mitochondrial membrane of the cristae.
The cristae are the inner folded membranes in mitochondria where the enzymes and
proteins involved in oxidative phosphorylation are located.
Some of these proteins are involved in the electron transfer chain: a series of electron carrier
molecules in the inner mitochondrial membrane that release energy in stages.
Releasing energy in stages allows more energy to be harvested for the benefit of the organism,
rather than being released as heat.
, Reactants of oxidative phosphorylation:
Reduced NAD
Reduced FAD
Oxygen
ADP and inorganic phosphate
Products of oxidative phosphorylation:
NAD
FAD
Water
ATP
Oxidative phosphorylation has several key steps:
1. Reduced NAD and reduced FAD release hydrogen, transferring protons (H +) and
electrons (e-) into the mitochondrial matrix.
2. High-energy electrons are passed to an electron carrier from reduced NAD and
reduced FAD.
3. The electrons are passed along a series of electron carrier molecules in the electron
transport chain embedded in the inner mitochondrial membrane, releasing energy
as they are transferred.
