talk about shape size and mitochondrial structure

1. Prepared by :
Nada Ibrahim

2. Occur in all Eukaryotic cells.
Involved in energy production.
contain enzymes for citric-acid cycle
Oxidative phosphoryation.
Production of ATP from ADP.

3. shape Very small organelles(0.5 *1-2 µm).
Higher plants Rod shape with hemispheroidal ends, Some
are cup or filamentous shape.
Vary from globular to threadlike or
branched
Animals Long filaments , not spatial in arrangement.

4. Distribution Cells with active processes, Near
wall ingrowths or chloroplast.
Free in the cytoplasm.
 Packed in rigid structures, such
among the myofibrils of cardiac
muscle tissue.

5. Numbers Depends on what the cell needs to do.
Examples Flagellated protozoa or sperm, they are found
around the base of the flagellum.
Cardiac muscle, they surround the contractile
parts.
Hummingbird flight muscle is the richest
sources of mitochondria.
Surviving When energy is not enough, more
mitochondria are created ,they grow, move, and
combine with other mitochondria.

6. Double membrane organelle.
The double-membrane described as a large
wrinkled bag packed inside of a smaller,
unwrinkled bag.
The two membranes create 3
compartments within the organelle differ in
structure and function.
Compartments The space between two membranes is
called inter-membrane space.

7. The matrix which fills the space of inner
mitochondrial membrane.
The cristae space (formed by infoldings of
the inner membrane).
Is
a smooth simple phospholipid bilayer
membrane.
Ions,nutrient molecules, ATP, etc pass
through outer membrane with ease.

8. Forming channels allow molecules of about
10 kilodaltons or less to freely diffuse.
The amount of phospholipids is higher than
integral proteins called porins.
The mitochondrial outer membrane can
associate with the (ER) membrane.
The ER-mitochondria calcium signaling and
the transfer of lipids between the ER and
mitochondria.

9. The inner membrane has infoldings called
the cristae.
 The cristae greatly increase the total
surface area of the inner membrane for the
complexes and proteins.
Is freely permeable only to O2,CO2,H2O.
Regulating transfer of metabolites across
the membrane.
It is made up of a large number of proteins
than phospholipids that control producing
ATP.

10. Inner membrane
Highly complex structure, including the
electron transport system, the ATP
synthetase complex, and transport
proteins.
NADH dehydrogenase which accept
protons carried by NADH from
tricarboxylic acid cycle.
Transmembrane proton channels
important in ATP synthesis.

11. Mitochondrial Matrix
Contains dissolved o2, h2o, co2, the
recyclable intermediates that serve as
energy shuttles.
 Diffusion is very slow due to folds cristae.
Citric acid cycle reactions occurrence.

12. Mitochondrial Matrix
Contain enzymes for the synthesis of ATP,
ribosomes, tRNAs and the mitochondrial
DNA.
Matrix components can diffuse to inner
membrane complexes and transport
proteins within short time.

13. Mitochondrial development
Human mitochondrial DNA sequence revealed
16,569 base pairs encoding 37 total genes:22 tRNA, 2
rRNA, and 13 peptide genes.
Has its own independent DNA which is similar to
bacterial DNA.
 Posses the machinery to manufacture their own
RNAs and proteins.
Reproduce by fission like bacteria do. due to their
independence from the nuclear DNA and similarities
with bacteria.