MITOCHONDRIA

1. MITOCHONDRIA
 SYED MASOOD

2. MITOCHONDRIA
1. MITOCHONDRIA IS THE
POWER HOUSE OF THE
CELL
2. NUMBER:ALGAE
CONTAIN ONLY ONE
MITOCHONDRIA,
WHEREAS PROTOZOAN
CHAOS CONTAIN HALF
A MILLION,MAMMALIAN
LIVER CELL CONTAIN
FROM 800 TO 2500
MITOCHONDRIA

3. SIZE OF THE
MITOCHONDRIA
 MAMMALIAN MITOCHONDRIA HAS A
DIAMETER OF 0.2 TO 0.8 MICRON AND A
LENGTH OF 0.5 TO 1.0 MICRONMETER
 SHAPE:IT’S SHAPE IS NOT STATIC.IT
HAS MANY DIFFERENT SHAPES UNDER
DIFFERENT METABOLIC CONDITIONS
LIKE ONION SHAPE OR ROD SHAPED

4. Onion shaped

5. STRUCTURE AND FUNCTIONS
 MITOCHONDRIA IS BOUNNDED BY
TWO CONCENTRIC MEMBRANES.

6. MITOCHONDRIAL MEMBRANE
 Outer membrane
 The outer mitochondrial membrane, which encloses the
entire organelle, has a protein-to-phospholipid ratio
similar to that of the eukaryotic plasma membrane (about
1:1 by weight).
 It contains large numbers of integral proteins called
porins. These porins form channels that allow molecules
5000 Daltons or less in molecular weight to freely diffuse
from one side of the membrane to the other.
 Larger proteins can enter the mitochondrion if a signaling
sequence .
 Disruption of the outer membrane permits proteins in the
intermembrane space to leak into the cytosol, leading to
certain cell death.
 The mitochondrial outer membrane can associate with the
ER membrane, in a structure called MAM (mitochondria-
associated ER-membrane). This is important in ER-
mitochondria calcium signaling and involved in the
transfer of lipids between the ER and mitochondria.

7. INNER MITOCHONDRIAL
MEMB.
 The mitochondrial inner membrane forms
internal compartments known as cristae, which
allow greater space for the proteins such as
cytochromes to function properly and
efficiently. The electron transport chain is
located on the inner membrane of the
mitochondria. Within the inner mitochondrial
membrane are also transport proteins that
transport in a highly controlled manner
metabolites across this membrane

8. Inter membrane space
 The space between the outer and inner
membrane is known as inter membrane space.
 It permits the small molecules as it is freely
permeable.

9. FUNCTIONS OF PORIN AND
OTHER PROTEINS
 These proteins form channels that permits
substances with M.Wt of <10000 to diffuse
freely across the outer mitochondrial
membrane.
 Other proteins in the outer memb. Carry out
various rxn. Fatty acids and phospholipid
biosynthesis.

10. Mitochondrial matrix
 The region enclosed by the inner membrane is known as
mitochondrial matrix.
 The matrix is important in the production of ATP with the
aid of the ATP synthase contained in the inner membrane.
 The matrix contains a highly-concentrated mixture of
hundreds of enzymes, special mitochondrial ribosomes,
tRNA, and several copies of the mitochondrial DNA
genome.
 Of the enzymes, the major functions include oxidation of
pyruvate and fatty acids, and the citric acid cycle.
 Mitochondria have their own genetic material, and the
machinery to manufacture their own RNAs and proteins.
 The 13 mitochondrial peptides in humans are integrated
into the inner mitochondrial membrane, along with
proteins encoded by genes that reside in the host cell's
nucleus.

11. Mitochondrial matrix

12. Composition of matrix
 The enzymes responsible for the citric acid
cycle and fatty acid oxidation are located in the
matrix.
 The matrix also contains several strands of
circular DNA, Ribosomes and enzymes
required for biosynthesis of proteins coded in
the mitochondrial genome.

13. Function of mito
 The most prominent roles of the mitochondrion are its
production of ATP (i.e., phosphorylation of ADP)
through respiration, and regulation of cellular
metabolism.
 The central set of reactions involved in ATP
production are collectively known as the citric acid
cycle, or the Krebs Cycle. However, the
mitochondrion has many other functions in addition
to the production of ATP.

14. Functions of mito
 Energy conversion
 A dominant role for the mitochondria is the
production of ATP, as reflected by the large
number of proteins in the inner membrane for this
task. This is done by oxidizing the major products
of glucose, pyruvate, and NADH, which are
produced in the cytosol.
 This process of cellular respiration, also known as
aerobic respiration, is dependent on the presence
of oxygen. When oxygen is limited, the glycolytic
products will be metabolized by anaerobic
respiration, a process that is independent of the
mitochondria.