Mitochondria are organelles found in the cytoplasm of eukaryotic cells that are known as the "powerhouses of the cell". They produce energy through oxidative phosphorylation to fuel cellular processes. Mitochondria have their own DNA and ribosomes and are thought to have originated from ancient bacteria that were engulfed by early eukaryotic cells in a endosymbiotic relationship. The inner mitochondrial membrane is folded into cristae to increase surface area for ATP production. Mitochondria are semi-autonomous and can replicate themselves to meet cellular energy demands.

1. “Powerhouse
of the
CELL”

2. Move?
Love?
Smile?
Think?
Eat?
Laugh?
and carry all process in everyday life?

3.  Mitochondria comes from the
Greek words ”mitos”, thread,
+ ”chondrion”, granule.
 It is granular of filamentous membrane
enclosed organelle found in the
cytoplasm of animals, plants and
even protozoan cells.
 Known as the“Powerhouse of the Cell”

4.  The shape of mitochondria is
variable , but in general these
organelles are filamentous or
granular.
 The size of mitochondria is also
variable; however in most cells
the width is relatively
constant(about 0.5μm) and the
length is variable reaching a
maximum of (7μm).

5. Mitochondria are semi-
autonomous in that they are
only partially dependent on the
cell to replicate and grow. They
have their
own DNA, ribosomes and can
make their own proteins.
 Similar to bacteria,
mitochondria have circular
DNA and replicate by a
reproductive

6.  It is first observed at the end of 19th
century & described by as
“BIOPLAST” by Richard Altmann
 The term “mitochondria” is
coined by Carl Benda (1898)
 And Philip Siekevitz (1957), dubbed
them as the “Powerhouse of the Cell”
 Friedrich Meves(1904) made the 1st
recorded observation in plants

7.  The examination of
mitochondria in living cell is
somewhat difficult because of
their low refractive index, they
can observed easily in cells
under dark field illumination
and phase contrast that are
greatly facilitated by coloration

8.  Mitochondria divides by binary
fission similar to bacterial cell
division; unlike bacteria , however ,
mitochondria can also fuse with
other mitochondria.
 Mitochondria may replicate their
DNA and divide mainly in the
response to the energy needs by the
cell. When the energy needs of the
cell are high, mitochondria grow and
divide. When the energy is low ,

9. The most important function
of the mitochondria is to produce energy.
The food that we eat is broken into simpler
molecules like carbohydrates, fats, etc., in
our bodies. These are sent to the
mitochondrion where they are further
processed to produce charged molecules
that combine with oxygen and produce ATP
molecules. This entire process is known as
oxidative phosphorylation.

10.  It is important to maintain proper
concentration of calcium ions within
the various compartments of the cell.
Mitochondria help the cells to
achieve this goal by serving as
storage tanks of calcium ions.
 They also help in the building of
certain parts of the blood, and
hormones like testosterone and
estrogen.
 Mitochondria in the liver cells have
enzymes that detoxify ammonia.

11.  They play an important role in the process
of programmed cell death.
 Cell death can occur either by injury due to
toxic exposure, by mechanical damage, or
by an orderly process called programmed
cell death or apoptosis. Programmed cell
death occurs during development as the
organism is pruning away unwanted,
excess cells. It also occurs during infections
with viruses, cancer therapy, or in the
immune response to illness. The process of
programmed cell death is another function
of mitochondria.

12.  Normally, ATP production is coupled to
oxygen consumption. During abnormal
states such as fever, cancer, or stroke,
or when dysfunction occurs within the
mitochondria, more oxygen is
consumed or required than is actually
used to make ATP. The mitochondria
become partially “uncoupled” and
produce highly reactive oxygen
species called free radicals.

13.  When the production of free radicals
overwhelms the mitochondria’s ability
to “detoxify” them, the excess free
radicals damage mitochondrial function
by changing the mitochondrial DNA,
proteins, and membranes. As this
process continues, it can induce the
cell to undergo apoptosis. Abnormal
cell death due to mitochondrial
dysfunction can interfere with organ
function.

14.  A mitochondrion contains outer and inner
membranes composed of phospholipid
bilayers and proteins. The two membranes,
however, have different properties. Because of
this double-membrane organization, there are five
distinct parts within the mitochondrion. They are:
 Outer mitochondrial membrane,
 Intermembrane space
 Inner mitochondrial membrane,
 Cristae space
 Matrix

15.  The outer membrane is smooth unlike
the inner membrane and has almost
the same amount of phospholipids as
proteins. It has a large number
of special proteins called porins,
that allow molecules of 5000
daltons or less in weight to
pass through it. The outer membrane
is completely permeable to nutrient
molecules, ions, ATP and ADP

17.  The intermembrane space is the
space between the outer membrane
and the inner membrane. It is also
called as Perimitochondrial space,
because the outer membrane is
freely permeable to small
molecules, the concentrations of
small molecules such as ions and
sugars in the intermembrane space
is the same as the cytosol.

18.  However, large proteins must
have a specific signaling
sequence to be transported
across the outer membrane, so
the protein composition of this
space is different from the
protein composition of the
cytosol. One protein that is
localized to the intermembrane
space in this way is cytochrome

20.  The inner membrane is more complex in
structure than the outer membrane as it
contains the complexes of the electron
transport chain and the ATP synthetase
complex. It is permeable only to oxygen,
carbon dioxide and water. It is made up
of a large number of proteins that play an
important role in producing ATP, and
also helps in regulating transfer of
metabolites across the membrane

22.  The inner mitochondrial membrane is
compartmentalized into
numerous cristae, which expand the
surface area of the inner mitochondrial
membrane, enhancing its ability to
produce ATP. This ratio is variable and
mitochondria from cells that have a
greater demand for ATP, such as
muscle cells, contain even more cristae.

23.  These folds are studded with small round
bodies known as F1 particles or oxysomes.
These are not simple random folds but
rather invaginations of the inner membrane,
which can affect
overall chemiosmotic function.

24.  The matrix is a complex mixture
of enzymes that are important for
the synthesis of ATP molecules,
special mitochondrial ribosomes,
tRNAs and the mitochondrial
DNA. Besides these, it has
oxygen, carbon dioxide and other
recyclable intermediates.

26.  A published human mitochondrial DNA
sequence revealed 16,569 base
pairs encoding 37 total genes:
22 tRNA, 2 rRNA, and
13 peptide genes.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. It is circular.

27.  It is smaller than cytoplasmic
ribosome
 They closely resemble the bacterial
70S ribosome and not 80S of
cytoplasmic ribosome.
 It appear to be tightly associated with
the membrane.
 But it contain more protein as of
prokaryotic cells

28.  Adenosine Triphosphate (ATP),
is the primary energy
source found in all living
things. ATP fuels most cell
activities, including muscle
movement, protein synthesis, cell
division, and nerve signal
transmission .

29.  The adenosine part of the
molecule is made up of adenine,
a nitrogen-containing compound
(also one of the principal
components of the gene), and
ribose, a five-carbon sugar. Three
phosphate units (triphosphate),
each made up of one phosphorus
atom and four oxygen atoms, are
attached to the ribose.

30.  Adenosine Triphosphate (ATP). In this
computer graphic representation of an
ATP molecule, the three phosphate
groups are shown in orange. ATP’s
chemical energy is stored in its
phosphate bonds..

31. There are important differences in
permeability between the
mitochondrial membranes. The
outer membrane is freely
permeable to electrolytes, water,
sucrose, and moleculesas large as
10,000 daltons.
The inner membrane, on the other
hand , is normally impermeable to
ions, as well as sucrose.

32.  Scientists once thought that
mitochondria and chloroplasts arose
in the same way. But a theory
proposed by American microbiologist
Lynn Margulis holds that these
organelles arose from certain
prokaryotes, which established
mutually beneficial relationships with
the earliest eukaryotes.

33.  In the distant past, these free-living
prokaryotes were consumed by early
eukaryotes, but managed to survive
within the cytoplasm.
 The autotrophic prokaryotes proved
useful to their hosts because they
produced glucose through
photosynthesis. The heterotrophic
prokaryotes also were useful because
they could generate the energy source
adenosine triphosphate (ATP) for the
host

34.  The host in turn provided protection for
the engulfed prokaryotes. Over time,
the autotrophic prokaryotes developed
into chloroplasts and the heterotrophic
prokaryotes developed into
mitochondria. These organelles still
contain their own DNA, with bacteria-
like genes, and their own ribosomes,
relics handed down from their distant
bacterial ancestors. This symbiotic
relationship probably developed 1.7 to
2 billion years ago.

35. PHOTOSYNTHESIS OXIDATIVE PHOSPORYLATION
Only in presence of light thus periodic Independent of light thus, continuous
Uses CO2 and H2O Uses molecular O2
Liberate O2 Forms water
Endergotic reaction(means it
captures energy)
Exergonic reaction(it releases
energy)
CO2 + H2O+ energy
foodstuff+ O2
foodstuff + O2 CO2 + H2O+
energy
The main function of chloroplast is
photosynthesis while that on mitochondrion is
oxidative phosphorylation .
Differences between photosynthesis and
oxidative phosporylation

37. Sa wakas na ka report din...
Sana nagenjoy kayo…
galingan nyo sa exam...hay….
SEM BREAK NA..’_’