Mitochondrial Biogensis Flashcards
How many proteins does the mitochondrial genome encode and what are they for?
13 essential proteins involved in electron transport and oxidative phosphorylation
How is the mitochondrial genetic code different?
Some codons specify different amino acids
U in the tRNA anticodon can pair with any of the bases in the third codon position of mRNA
What type of ribosome translates proteins within the mitochondria?
55s ribosome
What are three pieces of evidence for the endosymbiosis theory?
Separate genome
Ribosomes are sensitive to bacterial antibiotics
Proteins synthesized in mitochondria have N-formyl methionine as an initial amino acid
What is Myoclonic epilepsy with ragged-red fibers?
mutation on mt tRNA-Lys
Affects muscles and nervous system
symptoms appear during childhood or adolescence
What is Leber hereditary optic neuropathy?
Mutations in NADH dehydrogenase
Inherited form of vision loss
symptoms appear in a person’s teens or twenties
What is MELAS?
Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes
Mainly tRNA-Leu mutation
Affects brain and nervous system
What are four diagnostic tests for mitochondrial diseases?
Family history
Muscle Biopsy
Blood Tests
Genetic Tests
What are some supportive treatments for mitochondrial diseases?
Creatine, Co-Q10, ketogenic diet, carnitine, avoidance of fasting
Nucleoside bypass therapy
Three parent babies
How do mitochondrial defects affect cancer?
Defects in mitochondrial function generate ROS
ROS induce a TF called hypoxia-inducible factor 1-alpha (HIF1A)
HIF1A causes metabolic changes and blood vessel growth that feed tumors and promote metastasis
How do defects in mitochondra of pancreatic beta cells result in diabetes?
High caloric intake causing dysregulation of metabolic enzymes cause ETC and B-oxidation inefficiency
This results in overproduction of intracellular ROS and accumulation of lipids
Disruption of insulin signaling causes insulin resistance and diabetes
How does doxorubicin cause mitochondrial dysfunction?
Induces ROS production by binding to cardiolipin and increasing free iron accumulation
ROS production leads to induction of apoptosis
How does Zidovudin (azidothymidine AZT) cause cardiotoxicity?
Interferes with mDNA polymerase-y – will result in mitochondrial energetic imablance
Also inhibits mitochondrial ADP/ATP translocator
