The document summarizes key aspects of mitochondria. It discusses how mitochondria were first observed in 1850 and are commonly called the "powerhouse of the cell". It describes their structure, which includes an outer membrane, inner membrane, intermembrane space, and matrix. The inner membrane contains complexes involved in oxidative phosphorylation. The matrix contains enzymes for cellular respiration and expression of mitochondrial genes. Mitochondria are involved in many functions including energy production, calcium storage, hormone production, detoxification, and roles in processes like apoptosis. The document outlines mitochondrial dynamics of fission and fusion as well as biogenesis. It details the mitochondrial genome and genes encoded.

1. Dr. S. Subba Tata
M.Sc., M.Sc., M.Tech., Ph.D.
Assistant Professor (C)
Department of Botany, Andhra University
MITOCHONDRIA

2. KOLLIKER - 1850
MITOCHONDRIA were first observed as granular structures in
the striated muscles

3. 25 percent of the volume of the cytoplasm
Mature red blood cells - no Mitochondria
Popularly called POWERHOUSE OF THE CELL
MITOCHONDRIA
Carl Benda - 1898 - proposed – Mitochondria
mitos (thread) and chondrion (granule)

4. Present in all eukaryotic cells
Uniform distribution in the cytoplasm
Restricted distribution in many cells
Mitochondria with many cristae - mechanical and osmotic
work situations
 Muscle fibres
 Kidney tubule cells
 Rod and Cone cells of retina
Many large mitochondria - Sarcosomes - Myocardial
muscle cells
Localization

5. Present in all eukaryotic cells
Uniform distribution in the cytoplasm
Restricted distribution in many cells
Mitochondria with many cristae - mechanical and osmotic
work situations
 Muscle fibres
 Kidney tubule cells
 Rod and Cone cells of retina
Many large mitochondria - Sarcosomes - Myocardial
muscle cells
Localization

6. Number
Amoeba – 50,000
Eggs of sea urchin – 1,40,000 to 1,50,000
Oocytes of amphibians – 3,00,000
Liver cells of rat - 500 to 1600
Morphology
Shape
Filamentous
Granular
Club
Racket
Vesicular
Ring
Round
Size
Length : ~ 1-2μm
Width : ~ 0.1-0.5μm

7. STRUCTURE
Palade’s model
Infolding or ‘Baffle’ model
PALADE - 1952
Crista junction model
SJOSTRAND - 1953
Lea et al., 1994; Mannella et al., 1994

8. * Monoamine oxidase, rotenone-insensitive NADH-cytochrome-C-reductase,
kynurenine hydroxyalase and fatty acid CoA ligase *
Outer Membrane (OM)

9. hTom40 forms the pore of the translocase
hTom20, hTom22 and hTom70 function as receptors
hTom22 plays an additional role in the assembly of the complex
hTom5, hTom6 & hTom7 - small TOMs- regulate the dynamics and
assembly of the complex
Translocase of Outer Membrane
- serves as a general protein entry gate -

10. Sorting and Assembly Machinery
- serves to insert the proteins into the outer membrane -
hSam40 is a core protein of this complex – Insertion activity
MTX1 & MTX2 (Metaxins) – Protein sorting activity

11. Inner Membrane (IM)
Inner Membrane (IM)
IBM CM
Tubular Spherical Triangular Wavy Lamellar Strap

13. Translocase of
Inner Membrane
- serves to insert the proteins
into the inner membrane -
hTim22 forms the pore of
translocase
hTim29 function as receptor and
mediates the formation of complex
 AGK (Acylglycerol kinase) –
Lysophosphatidic acid (shows
growth factor like activity)

14. Mitochondrial Intermembrane Assembly
- serves to assemble the proteins in the intermembrane space by
catalyzing the disulfide bonds -
hMia40 is a core protein of this complex – Assemble & disulfide bonds
AIF – Apoptosis Inducing Factor
ALR – Augmenter of Liver Regeneration – Mitochondrial Biogenesis

15. Translocase of Inner Membrane
- serves to insert the proteins into the inner membrane and to
transfer the proteins into the matrix -
hTim23 and hTim17 forms the pore of translocase
hTim50 function as receptor
Import motor – helps to translocate the proteins into the matrix

16. Multi – Subunit Complex
- serves to stabilize the Cristae-
Mic60 is a core protein of this complex
MICOS – intern to associates with SAM complex to form MIB for the
stability of both the membranes

17. Inner Membrane (IM)
Nicotinamide adenine dinucleotide dehydrogenase (NADH)
Flavin adenine dinucleotide dehydrogenase (FADH)
Diphosphopyridine nucleotide dehydrogenase (DPNH)
ATP synthetase
Succinate dehydrogenase
β-hydroxybutyrate dehydrogenase
Carnitive fatty acid acyl transferase
Four cytochromes (Cyt. b, Cyt. c, Cyt.c1, Cyt. a and Cyt. a3)
Ubiquinone or coenzyme Q10
Non-heme copper and iron

18.  Inner membrane proteins
 Oxidative phosphorylation
 Metabolite exchange
 Protein translation
 Protein translocation
 Protein degradation
 Iron/Sulfur cluster biogenesis
 Mitochondrial morphology
CM
Oxidative phosphorylation
Iron/Sulfur cluster biogenesis
Protein synthesis
Transport of mtDNA-encoded proteins
Proteins involved in mitochondrial fusion
Protein transport of nuclear-encoded proteins
IBM

19.  consists a complex mixture of
enzymes - for the oxidation of
pyruvate and fatty acids and for
the citric acid cycle and for
expression of mitochondrial
genes
Ribosomes
tRNAs
DNA
Oxygen, Carbon dioxide and
other recyclable intermediates
Matrix

20.  Adenylate kinase
 Nucleoside diphosphokinase
Intermembrane space

21.  Produce energy
 Storage tank of calcium ions
 Building of certain parts of the blood and hormones
(e.g. testosterone and estrogen)
Detoxification of ammonia
Participates in diverse cellular process like: immune
responses ; mitophagy ; stress signalling and apoptosis
Functions

26. Mitochondria Biogenesis
Mitochondrial fission
- Mitochondria reproduction -
Drp1 : Dynamin related protein 1
Fs1 : Fission protein 1
Mff : Mitochondrial protein factor 1
Mid49: Mitochondrial dynamics protein 49
Mid51: Mitochondrial dynamics protein 51

27. DYNAMIN RELATED PROTEIN 1
 Mechanochemical enzyme
 4 domains - Tertiary structure
 Contains – 736 amino acids
 Molecular weight – 81.6kDa

28. 1
2 3 4
1 : Fission protein 1
2 : Mitochondrial protein factor 1
3 : Mitochondrial dynamics protein 49
4 : Mitochondrial dynamics protein 51
Mitochondrial fission

29. 1
2 3 4
1 : Fission protein 1
2 : Mitochondrial protein factor 1
3 : Mitochondrial dynamics protein 49
4 : Mitochondrial dynamics protein 51

30. Mitochondrial Genome

32.  Circular ds DNA
 16,569bp – hMt DNA
 Outer stand – Heavy
 Inner strand – Light
 Both strands acts as non
coding strands (HSP1 & HSP ;
LSP)
 Each strand possess one Ori
for replication
 Only one non – coding DNA
region identified - D- loop
(~1kbp)
 Contains 37 genes
 Protein coding genes – 13
ND1; ND2; ND3; ND4;
ND4L; ND5 & ND6 of
complex – I (7/43)
Cyt b of complex –III (1/11)
COXI; COXII & COXII of
complex – IV(3/13)
ATPase6 & ATPase8 of
complex –V(2/16)

33. Ribosomal RNA coding
genes – 2
 12S RNA
 16S RNA
 tRNA coding genes – 22
Heavy Strand
T D
L W
S M
H I
R L
G V
K F
Light Stand
P C
E N
S A
Y Q

35. THANK YOU