- Range from 0.5-1μm in diameter (similar to bacteria).
- Contain an inner (folds in) and outer membrane.
- Contain cristae (singular crista) - internal compartments formed by the inner membrane folds.
- Contain a matrix- large overall internal compartment.
In sexual reproduction only the female gamete (ovum) has mitochondria when the gametes eventually fertilise, this is because the male gamete (sperm) draws upon all of its mitochondria for locomotion, to aid its travel to the ovum (egg). Furthermore, mitochondria in relation to the structure of the sperm, is wrapped tightly around the flagellum in the sperm and is fixed in this position, to enable the mitochondria to comply with the sperm's unusually high ATP consumption .
Mitochondrion is the site of the Krebs cycle and the electron transport chain in eukaryotic organisms. It has a variable diameter from 0.5 to 1 micrometre thus can be easily seen under a light microscope. Using time-lapse microcinematography, it has been established that mitochondria can alter their shape continuously, and are also able to fuse and separate with other mitochondria. It is surrounded by two phospholipid membranes: the outer and inner membrane. The inner membrane is folded inwards to form cristae and it is the location where electron transport chain occur. On the other hand, the outer membrane is the envelope that holds all the organelles and it is relatively permeable to small molecules. The internal mitochondrial compartment is called the matrix where the link reaction and Krebs cycle occur. As a result of oxidative phosphorylation, ATP is synthesised in the latter by the activity of ATP synthase on the cristae. The advantage that this has over glycolysis is that it reaps 15 times more ATP for all energy-requiring reactions of the cell, both inside and outside the mitochondria. Moreover, it has its own DNA which is circular and also contains 70S ribosomes. In addition, it is also beneficial in the event of cell damage, as it is the one who signals the process of apoptosis (programmed cell death) by releasing mitochondrial protein into the cytoplasm .
- ↑ Berg J.M, Tymoczko J.L., Stryer L (2001) Biochemistry, 5th edition, New York: WH Freeman. p492
- ↑ Molecular Biology of THE CELL, Fifth Edition, Alberts, Johnson, Lewis, Raff, Roberts, Watter (2008), Chapter 1 Cells and Genomes, Figure 1-33 A mitiochondrion, Page 28
- ↑ Bruce Alberts (et al)-2007: pg815
- ↑ Alberts, Johnson, Lewis, Raff, Roberts, Walter (2008) Molecular Biology of the cell, Fifth edition, p815
- ↑ Berg J.M, Tymoczko J.L, Stryer (2012) Biochemistry, seventh Edition, New York: WH Freema.. pg 543
- ↑ Alberts, Johnson, Lewis, Raff, Roberts, Walter (2008) Molecular Biology of the cell, Fifth edition, pg 815