This document provides information on mitochondria, Golgi bodies, and plastids. It describes the key structures and functions of each organelle. Mitochondria are described as the powerhouses of the cell that produce ATP through cellular respiration. Golgi bodies function in transport, packaging, and modification of proteins and lipids. Plastids, such as chloroplasts, chromoplasts, and leucoplasts, play important roles in photosynthesis, pigment storage, and starch/protein storage in plants.

1. Cell biology-Mitochondria ,Golgi
bodies ,Plastids
MOHMED JUNED
Junior Msc
Department of genetics and plant
breeding
College Of Agriculture,VC Farm
Mandya

2. MITOCHONDRIA
• Mitochondria is derived from the Greek word “Mito”-
Thread, “Chondrion” –granule .
• Mitochondria are thread like granular cytoplasmic
organelles that contain many specific enzymes and co-
enzymes neccessary for metabolism.
• It was first observed by the scientist Kolliker in 1850 in the
straited muscles.
• The term Mitochondria was coined by Benda in 1897.
• Richard Altman in 1890 developed specific stain that had
useful specificity for the mitochondria.
• Granular or filamentous organelles present in the
cytoplasm of protozoa ,animal and plant cell .
Introduction-

3. • Occurrence- It is present in all
eukaryotic cells and absent in
Prokaryotic cells.
• Shape- Mitochondria appears
ellipsoid or oval structure.
• Size – length - 3 to 10 μm .
Diameter - 0.2 to 1 μm .
• Distribution – Uniformly distributed
through out cytoplasm .
• It contains Protein- 75 % ,lipid -25-
30% ,DNA and RNA - <1%.
• It divides by fission and is called
Semi –Autonomous organelle.

4. Ultrastructure of Mitochondria -
• In 1953, Palade and Jonstrad
independently described the
ultrastructure of mitochondria.
• It is bounded by two unit
membrane called outer
membrane and inner
membrane .
• The space between the two
membranes is called inter
membrane space.
• Number of invaginations occur
in the inner membrane called
Cristae.

5. • Outer membrane- it is
around 60 Å. It is highly
permeable to the molecules
of sugar ,salts ,co-enzymes
and nucleotides . It consists
of the many enzymes for
protein synthesis and lipid
synthesis.
• Inner membrane space – it
is selectively permeable
and infolded with the
invaginations called
Cristae.
• Cristae- they increase the
surface area of inner
membrane for enzymatic
activity.

6. • Matrix –space outside the cristae inside that of inner
membrane space is called matrix.
• Inner membrane is filled with the colorless ,granular
matrix of protein and lipids.
• Matrix contains 70s type of Ribosomes, DNA,RNA.
• It also consists of insoluble salts like Mg2+ and Ca2+
ions.
• F1 particles- they are required for ATP synthesis.

7. Mitochondria acts as Power House of Cell-
• Mitochondria is the site of cellular respiration.
• It produces energy rich ATP molecules during oxidation
of glucose by oxidative energy.
• The energy rich ATP molecules are readily available for
various activities of the cells.
• As mitochondria produces, stores and supplies biological
energy hence called as” POWER HOUSE OF CELL.”

8. Functions-
• They are site for aerobic respiration.
• Krebs cycle and Electron transport system takes place in
mitochondria.
• They generate ATP molecules hence the are called as
power house of the cell.
• It is involved in the cytoplasmic inheritance i.e is
mitochondrial DNA (mtDNA) controls the male sterility.
• It stores and releases calcium and regulate its
concentration in the cell.

9. GOLGI COMPLEX-
• Camellio Golgi in 1898 discovered a internal reticular
apparatus in the nerve cells.
• Golgi complex is differentiated portion of the
endomembrane system which is morphologically very
similar in animals and plants .
• It is also called Dictyosome in plant cells.
• Golgi bodies are originated from Endoplasmic reticulum.

10. Ultrastructure of Golgi bodies -
• It is stack of 20 or
more than flattened
smooth sacs enclosed
by membrane.
• Curved convex
appearance are called
as Cis –face and on
one side concave
appearance called as
trans-face .
• There are vesicles and
membranous channels
associated with the
Golgi-complex.

11. • Flat cisternae have a
polarized structure
proteins modified in
Endoplasmic reticulum
enter golgi bodies at
cis face of cisternae
and exit from trans
face of cisternae.
• Number of golgi bodies
in the cell depends
upon the synthetic
acticvity ,more the
number of golgi bodies
more is the synthetic
activity of the cells.

12. Functions of golgi bodies -
• Transport of the substances from the endoplasmic
reticulum.
• Helps in packaging of lipid molecules ,proteins.
• Selection and modification of proteins.
• Production of mainly Proteoglycans.
• Plays major role in Apoptosis.
• Sulfation generally in trans face of golgi body.
• Release of secretory protein mediated by Ca+2 ions .

13. PLASTIDS
• Plastids are the cytoplasmic organelles .
• They are major organelles in the cells of the plants and
algae.
• The term plastids derived from Greek word “Plasticas “
meaning moulded.
• The term plastid was given by Schimper in 1885.
• They are found in most of the plants except bacteria and
fungi.

14. TYPES AND FUNCTIONS OF PLASTIDS-
1. CHROMOPLASTS
2. LEUCOPLASTS
3. CHLOROPLASTS
 Chromoplasts-
 They are pigmented plastids.
 They have the pigments like carotenoids ,xanthophyll,
phycoerythrin, fucoxanthin.
 These are found in flowering plants ,fruits and aging
leaves.

15. Leucoplasts –
 They are colourless plastids.
 They lack pigments and present in non photosynthetic
parts of the plants such as roots.
• Leucoplasts are further sub –divided into the three
categories –
 Amyloplasts-leucoplasts that store starch.
 Elaioplast –leucoplasts that store oil.
 Aleurenoplasts/Proteinoplasts- leucoplasts that
store proteins.

16. CHLOROPLASTS
• Chloroplasts are probably the most known of the
plastids.
• Photosynthesis occur in the specific organelle called
Chloroplast.
• Chloroplasts were first described by the Nehemiah grew
and Antonie van leuwenhoek.
• In higher plants it is present in the mesophyll cells.

17. Ultrastructure of Choloroplast-
• Shape-Chloroplast are
typically bi-convex lens
shaped plants .
• Size-Size varies from
species to species in higher
plants thickness – 3μ ad
Diameter –5 μ.
• Number- the cells of
higher plants have 20-40
chloroplasts.
• Distribution –Chloroplasts
remain distributed
homogenously in the
cytoplasm.

18. • Chloroplasts are bounded
by two unit membranes,
• The space between the
outer and inner membrane
is called Peri-plastidial
space,
• It consists of mainly
A. Stroma
B. Grana

19. STROMA GRANA
•Stroma – the inner periplastidial
space of the chloroplast filled with
the transparant substance called
stroma.
•It contains many enzymes such as
RUBP Carboxylase, which is
required for the dark reactions of
photosynthesis
•Dark reactions of photosynthesis
occurs in stroma.
•Grana –it has flattened
memebranous sacs called
thylakoids.
•Interconnecting membranes of the
grana are called as stroma lamellae
or fret channels .
•Light reactions of photosynthesis
takes place in Grana.