mitochondria & nucleus
TRANSCRIPT
Kanav BhanotRoll no. 05
Presentation on
MITOCHONDRIA&
NUCLEUSby
CONTENTS
MITOCHONRIA
What is Mitochondria?
Structure
Functions NUCLEUS
What is Nucleus?
Structure
Functions Summary
BIBLIOGRAPHY
MITOCHONDRIAPowerhouse of the Cell
The mitochondrion (plural mitochondria)
are called the “powerhouses” of the cell.
Without them cells would be unable to
extract enough energy from the nutrients
and essentially all cellular functions
would cease.
What is mitochondria ?
• The term "mitochondria" itself was coined by
Carl Benda in 1898.
• The word mitochondrion comes from the Greek
word mitos i.e. "thread“ and chondrion i.e.
"granule".
• The mitochondrion (plural mitochondria) is a
membrane-bound organelle found in most
eukaryotic cells. Mitochondria range from 0.5 to
• These structures are sometimes described as "cellular
power plants" because they generate most of the cell's
supply of adenosine triphosphate (ATP), used as a
source of chemical energy.
• In addition to supplying cellular energy, mitochondria
are involved in other tasks such as signalling, cellular
differentiation, cell death, as well as the control of the
cell cycle and cell growth.
• Mitochondria has its own DNA which is responsible for
many enzymatic actions. Infact, it is the only organelle
other than nucleus which has its own DNA.
Structure
• The outer mitochondrial membrane
• The intermembrane space (the space
between the outer and inner membranes)
The basic structure of mitochondria is composed of two
lipid bilayer-protein membranes: an outer and an inner
membrane. The two membranes have different properties.
Because of this double-membraned organization, there are
five distinct parts to a mitochondrion. They are:
• The inner mitochondrial membrane
• The cristae space (formed by infolding of
the inner membrane)
• The matrix (space within the inner
membrane)
FUNCTIONS
Production of Energy
Mitochondria is called the “Power House” of the cell because it
produces the energy required for cellular functions. The energy
is produced during the oxidation of digested food particles like
proteins, carbohydrates and lipids by the oxidative enzymes in
cristae. During the oxidative process, water and CO2 are
produced with release of energy. The released energy is stored
in mitochondria and used later for synthesis of ATP.
Synthesis OF ATP
The components of respiratory chain in mitochondrion are
responsible for the synthesis of ATP by utilizing the energy
by oxidative phosphorylation. ATP molecules diffuse
throughout the cell from mitochondrion. Whenever energy
is needed for cellular activity the ATP molecules are
broken down.
ADDITIONAL FUNCTIONS
Additional functions of mitochondria include:
Apoptosis
Storage of calcium
Detoxification of ammonia in liver
NUCLEUSBrain of the Cell
The nucleus is the “control centre”
of the cell. It is the most important
part of the cell, exerting a
controlling influence on all cell
What is Nucleus ?
In cell biology, the nucleus (pl. nuclei; from Latin
nucleus or nucleus, meaning kernel) is a membrane-
enclosed organelle found in eukaryotic cells.
It was discovered by A.V Leeuwenhoek for the first
time. Scottish Botanist Robert Brown explained it in
more detail in 1831.
It coordinates the cell’s activities, which include
growth, intermediary metabolism, protein synthesis
and reproduction (cell division) by regulating gene
Structure
The nucleus is the largest cellular organelle in animals. In
mammalian cells, the average diameter of the nucleus is
approximately 6 micrometres (μm), which occupies about
10% of the total cell volume. Structure of Nucleus is made
up of following:
•Nuclear Membrane • Nuclear
Pores
• Chromatin •
NUCLEAR MEMBRANE
Nuclear Membrane separates the nucleus from the
cytoplasm. It is mainly made up of protein and lipids.
The nuclear envelope, otherwise known as nuclear
membrane, consists of two cellular membranes, an
inner and an outer membrane, arranged parallel to
one another.
The outer nuclear membrane is continuous with the
membrane of the rough endoplasmic reticulum (RER),
Nuclear Membrane
NUCLEAR PORES
The nuclear pores are the gateways across which
movement of RNAs and proteins takes place between
the nucleus and cytoplasm in both direction.
Each pore contains a donut-shaped, eightfold-
symmetric ring-shaped structure at a position where the
inner and outer membranes fuse.
The nucleus of a typical mammalian cell will have about
3000 to 4000 pores throughout its envelope.
Nuclear Pore
CHROMATIN
Chromatin is a thread like material made up of large
molecules of DNA.
The DNA molecule is compactly packed with the help of
specialised basic protein called histone. So chromatin
is referred as DNA Histone Complex.
The fundamental packing unit of chromatin is called
Nucleosome. Just before cell division the chromatin
NUCLEOPLASM
The nucleoplasm is a highly viscous liquid that
surrounds the chromosomes and nucleoli.
Similar to the cytoplasm of a cell.
Many substances such as nucleotides (necessary for
purposes such as the replication of DNA) and
enzymes (which direct activities that take place in the
nucleus) are dissolved in the nucleoplasm.
• The nucleolus is a discrete densely stained structure
found in the nucleus.
• A nucleolus is composed of Ribonucleic acid (RNA)
and associated proteins.
• The nucleolus produces ribosomes, which move out
of the nucleus and take positions on the rough
endoplasmic reticulum where they are critical in
protein synthesis.
NUCLEOLUS
NUCLEOLUS
NUCLEAR PORENUCLEAR MEMBRANE
FUNCTIONS
It stores the cell hereditary material, or DNA.
Site of DNA replication
Site of DNA transcription to mRNA
Ribosomal formation
Control of all cell activities that include metabolism,
protein synthesis, growth and reproduction (cell
division).
SUMMARY
From the aforesaid presentation we can conclude that
Mitochondria and Nucleus play a vital role in the normal
functioning of the cell and in case of any malfunctioning in any
of the two organelles, all the essential functioning of the cell
would cease and eventually the cell would die.
So I believe that I have been able to convey the importance of
Mitochondria & Nucleus in the normal functioning of the cell.
Bibliography
The sources that enabled me to bring out this
presentation to you all are :
TEXTBOOK OF MEDICAL PHYSIOLOGY by
GUYTON AND HALL
www.wikipedia.com