Structure
Mitochondria is about 1 mm in diameter and 1-10 mm in length. Mitochondria
have dynamic structures that move, change their shape and divide.
Enclosed by two membranes that have proteins embedded in phospholipid
bilayers
Outer membrane is smooth and highly permeable to small solutes, but it
blocks passage of proteins and other macromolecules
Inner membrane is convoluted and contains embedded enzymes that are
involved in cellular respiration. The membrane’ have many infoldings called
cristae which increase the surface area available for these reactions to occur.
The inner and outer membranes of mitochondria divide it into two internal
compartments: inntermembrane space is the narrow region between the inner
and outer mitochondrial membranes.
It resembles the solute composition of the cytosol,because the outer
membrane is permeable to small solute molecules.
Mitochondrial matrix is the compartment enclosed by the inner
mitochondrial membrane
It contains enzymes that catalyze many metabolic steps of cellular
respiration
Some respiratory enzymes are embedded in the inner membrane.
Functions of Mitochondria
The major function of the mitochondria is to produce energy. The energy
giving food molecule are sent to the mitochondrion where they are further
precessed to produce charged molecules that combine with oxygen and produce
ATP molecules. This total process is known as oxidative phosphorylation.
NADH and FADH2 from glycolysis, pyruvate oxidation, and the citric acid
cycle are oxidized by the respiratory chain, regenerating NAD+ and FAD. Most of
the enzymes and other electron carriers of the chain are part of the inner
mitochondrial membrane. Oxygen (O2) is the final acceptor of electrons and
protons, forming water (H2O).
A Chemiosmotic Mechanism Produces ATP As electrons pass through the
series of protein complexes in the respiratory chain, protons are pumped from
the mitochondrial matrix into the intermembrane space.As the protons return to
the matrix through ATP synthase, ATP is formed.