What is Cardiolipin?
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Asked in Laboratory Testing
What does a lab result of 24.5 mean for the cardiolipin igm test?
Asked in Conditions and Diseases, Genetics
The mitochondria do not function properly in people with Barth Syndrome because the mutated gene alerts or inhabits the production of what biomolecule?
Asked in Biology, Cell Biology (cytology), Mitochondria
Why is the mitochondria's structure good for its function?
To answer your question, we must first understand what mitochondria structure IS. The mitochondria is a double membraned organelle whose inner membrane is extremely selective in its permeability (it's made up of cardiolipin, which allows for many other functions to occur, such as apoptosis (programmed cell death)). The inner membrane is also corrugated, meaning the membrane has this funky folded shape. So why is it good? The funky folded shape of the inner membrane is for increased surface area. As you may know, electron transport chains (ETC) which create a proton gradient which is used to create ATP (adenosine triphosphate) for the cells use reside in and on the inner membrane. The more membrane, the more space for ETCs, the more ATP! The fact that the inner membrane is highly impermeable allows for different environments to occur in the matrix (space enclosed by the inner membrane) and the intermembrane space (space between the two membranes). Why is this so necessary? It allows for a proton gradient to be formed. Hydrogen ions ('protons') are then shifted from outside of the matrix to the inside while another structure in the membrane, ATP synthase, uses the gradient to create ATP. Another interesting thing about the inner membrane is that it's highly impermeable to most things EXCEPT oxygen, water and carbon dioxide... from what we know about cellular respiration, the answer should be very clear as to why this is useful... ;D
Asked in Microbiology, Cell Biology (cytology)
What are Mitochondria made of?
Mitochondria are phylogenically most closely related to the microbe Rickettsia prowazekii. They are thought to be monophyletic. Therefore, the mitochondrion are an extremely interesting and important organelle in eukaryotic cells. It is the only organelle (other than the nucleus, of course) that has its own DNA independent of the cell's chomosomal DNA; because of this and the fact that the organelle divides independent of the cell, the mitochondrion is thought to have once been a bacterial cell that colonized a eukaryotic cell. Among other things, it performs cellular respiration, has an eletron transport system that occurs across membranes, and produces ATP. The mitochondrial DNA is most similar to the genome of Rickettsia prowazekii; both have been described as small, highly derived, and "reduced and tailored to suit its dependent lifestyle " (Gray 1998). The structure of the DNA is double-stranded, circular, and about 16,569 bp in length for human mitochondria. One non coding part of the DNA, called the D-loop, is triple stranded and contains extra 7S DNA. Generally, there are 2 to 10 copies of the DNA in each mitochondrion and many mitochondia in each cell. The mtDNA encodes for 37 genes including 13 mitochondrial peptide subunits, 2 rRNAs, and 22 tRNAs (WUSTL). However, there is a large difference in the limited coding capacity of animal mitochondria and the relatively "large, complicated genomic architectures" of plant mitochondria (Kurland and Andersson 2000).The mitochondrion has four compartments: an outer membrane, an inner membrane (made of cardiolipin), an intermembrane space (between outer and inner membranes), and a matrix (inside inner membrane). The processes that happen in the mitochondron are pyruvate oxidation, the Krebs cycle, the metabolism of amino acids, fatty acids, and steroids, and generation of adenosine triphosphate (ATP). ATP, which is used for energy, is made through the electron-transport chain and the oxidative-phosphoylation system (respiratory chain) in the inner mitochondrial membrane. (WUSTL) View an animated diagram of the proton pump and ATP synthesis from WUSTL. Notice the folds, or cristae, that adds surface area to the mitochondrial inner membrane on the picture and diagram to the right. Mitochondria are thought to be aerobic bacterial cells much like Rickettsia bacteria that colonized primordial eukaryotic cells without the ability to use oxygen. Thus, these intracellular aerobic bacteria added oxidative metabolism to the eukaryotic cells and eventually evolved into mitochondria. (WUSTL) A theory on why a bacterium became an organelle has to do with the increase in ambient oxygen tension in Earth's atmosphere approximately 2 billion years ago. Supposedly, the oxygen tension went from 1% to more than 15% of the current levels within about 200 million years; this "environmental trauma" is thought to have pushed the symbiosis that lead to mitochondria organelles in primitive eukaryotes. (Kurland and Andersson 2000)
Movement - unpredictable or jerky?
Definition Jerky body movements is a condition in which people make fast movements that they cannot control and that have no purpose. These movements interrupt their normal movement or posture. Alternative Names Jerky body movements; Chorea; Muscle - jerky movements (uncontrolled); Hyperkinetic movements Considerations Typical movements of chorea include: Bending and straightening the fingers and toes Grimacing in the face Raising and lowering the shoulders This condition can affect one or both sides of the body. These movements do not usually repeat. They can look like they are being done on purpose, although they are not under the person's control. A person with chorea may look jittery or restless. Common Causes There are many possible causes of unpredictable, jerky movements, including: Huntington's disease Sydenham chorea Wilson's disease Other rare disorders Some medical illnesses that can cause chorea include: Anti-cardiolipin antibody syndrome Disorders of calcium, glucose, or sodium metabolism Polycythemia rubra vera Stroke Systemic lupus erythematosus Thyroid disease Other possible causes of chorea include: Benign hereditary chorea (an inherited condition) -- rarely Pregnancy (chorea gravidarum) Tardive dyskinesia (a condition that can be caused by medications such as antipsychotic drugs) Home Care Treatment is aimed at the cause of the movements. If the movements are due to medication, the drug should be stopped, if possible. If the movements are due to a medical disease, the disorder should be treated. If the movements are severe and affect the person's life, medications such as amantadine or tetrabenazine may help control them. Excitement and fatigue can make chorea worse. Rest improves chorea. Try to reduce emotional stress. Safety measures should also be taken to prevent injury from the involuntary movements. Call your health care provider if Call your health care provider if you have unexplained body motions that are unpredictable and do not go away. What to expect at your health care provider's office The health care provider will take a medical history and perform a physical examination. Medical history questions may include: What kind of movement occurs? What part of the body is affected? What other symptoms are present? Is there irritability? Is there weakness or paralysis? Is there restlessness? Is there emotional instability? Are there facial tics? The health care provider may do a detailed examination of both the nervous and the muscle systems. Tests that may be performed include: Blood work such as a complete blood count (CBC) or blood differential CT scan of the head or affected area EEG (rarely) Lumbar puncture MRI of the head or affected area Urinalysis Unpredictable movements may be treated with different medications. Your health care provider will decide which medicine to use based on your symptoms and signs. References Jankovic J, Lang AE. Movement disorders: diagnosis and assessment. In: Bradley WG, Daroff RB, Fenichel GM, Jankovic J, eds. Bradley: Neurology in Clinical Practice. 5th ed. Philadelphia, Pa: Butterworth-Heinemann Elsevier; 2008:chap 23. Lang A. Other movement disorders. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 434. Subramony SH. Ataxic disorders. In: Bradley WG, Daroff RB, Fenichel GM, Jankovic J, eds. Bradley: Neurology in Clinical Practice. 5th ed. Philadelphia, Pa: Butterworth-Heinemann Elsevier; 2008:chap 22. Reviewed By Review Date: 02/05/2011 David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by Joseph V. Campellone, MD, Division of Neurology, Cooper University Hospital, Camden, NJ. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.