Which side of the inner mitochondrial membrane has a higher pH?
1. It generates a pH gradient across the inner mitochondrial membrane, with the pH higher in the matrix than in the cytosol, where the pH is generally close to 7. (Since small molecules equilibrate freely across the outer membrane of the mitochondrion, the pH in the intermembrane space is the same as in the cytosol.)
Is the inner mitochondrial membrane the same as cristae?
The structure of the inner mitochondrial membrane is extensively folded and compartmentalized. The numerous invaginations of the membrane are called cristae, separated by crista junctions from the inner boundary membrane juxtaposed to the outer membrane. The inner membrane creates two compartments.
What happens on the inner cristae of the mitochondrial membrane?
To increase the capacity of the mitochondrion to synthesize ATP, the inner membrane is folded to form cristae. These folds allow a much greater amount of electron transport chain enzymes and ATP synthase to be packed into the mitochondrion.
How is the pH difference maintained in mitochondria?
The outer mitochondrial membrane is highly permeable [145,146]. This pH difference is thus likely due to increased proton concentration in the cristae interiors (pH out in our terminology), which may therefore be even more acidic than the combined pH presumably measured in [144] .
What is the pH of mitochondrial inner membrane?
Mitochondrial matrix has a pH of about 7.8, which is higher than the pH of the intermembrane space of the mitochondria, which is around 7.0–7.4. Mitochondrial DNA was discovered by Nash and Margit in 1963.
Which side of the inner mitochondrial membrane would have a lower pH?
This means that the protons need to be pumped across the inner mitochondrial membrane into the intermembrane space. This results in the intermembrane space having the lowest pH in the mitochondria, due to the high proton concentration.
How does the inner mitochondrial membrane differ from the outer mitochondrial membrane?
As previously mentioned, mitochondria contain two major membranes. The outer mitochondrial membrane fully surrounds the inner membrane, with a small intermembrane space in between. In contrast, the inner membrane has much more restricted permeability, much like the plasma membrane of a cell.
What are the folds on the inner mitochondrial membrane called?
Each mitochondrion has two membranes: an inner membrane which is highly convoluted and folded into finger-like projections called cristae, and a smooth outer membrane that is a selective barrier to molecules from the cytoplasm.
How does pH affect mitochondria?
Low pH increases the concentration of base causing mitochondria to pump out H+ to the inter membrane space leading to ATP production. The high external acid concentration causes an increase in H+ in the inter membrane space leading to increased ATP production by ATP synthetase.
Why does the mitochondrial matrix have a higher pH?
The ETC makes sure — under normal conditions — that the mitochondrial inter-membrane space holds more H ions than the matrix, thus creating an electrochemical proton gradient, the potential energy of which drives ATP synthesis. More hydrogen lower potential hydrogen (pH) more acidic.
