Lesson #6 Flashcards
True or false: The mitochondria have around 90 proteins within it, for various usages. The majority of the proteins are encoded for by mtDNA, while a small portion is encoded for by nDNA.
FALSE - The majority of proteins used in the mitochondria, are encoded for by nuclear DNA.
If the ETC is dysfunctional, what would occur?
There would be a build-up of free radicals, which will damage mtDNA, and further disable the ETC - Eventually causing necrosis and apoptosis.
Leber congenital amaurosis (LCA) -
The most severe mitochondrial disorder, causing retinal dystrophy. Encoded for by nDNA.
Leber hereditary optic neuropathy (LHON) -
Progressive deterioration of the optic nerve. This is the most common mtDNA disorder.
Kearns-Sayre Syndrome -
Degeneration of retinal pigments, weakness of occular muscles, cardiac conductance defect.
Encoded by mtDNA.
How are mitochondrial disorders passed down thru generations?
Mitochondrial disorders are passed down by the mother, but affect all offspring. - Maternal inheritance pattern.
Mitochondrial disorders effect most organ tissues. Which of the following would be most severely affected?
a. Skeletal muscle.
b. Liver and kidneys.
c. Ocular.
d. Skeletal bones.
A - Skeletal muscles.
Skeletal muscle, cardiac muscle, and brain tissues utilize the most energy, and therefore will be more severely affected by a dysfunction of the mitochondria.
What histological feature is unique to mitochondrial disorders?
Ragged red fibers (RRF’s) - enlarged myofibers.
Function of the smooth ER:
Lipid and glycogen metabolism, Ca++ storage, and detoxification.
What protein will catalyze many reactions in drug metabolism and synthesis of cholesterol, steroids, and other lipids?
Cytochrome P450 Proteins.
__________: Caused by alcohol and barbiturates - causes SER hyperplasia + increased detoxification. Causes a lower-than-expected concentration of therapeutic drugs.
Induction.
__________: Caused by proton receptor blockers + histamine blockers + macrolides. Decreases drug detoxification, causing higher than-expected therapeutic drug levels.
Inhibition.
Cytochrome P450 proteins are encoded for by what genes? Which specific one is responsible for 43% of cytochrome P450 proteins?
- CYP genes.
- CPY3A4.
True or false: A patient who is taking a pharmecutical drug that’s main function is by utilizing CYP3A4 enzyme, has just drank a large glass of grapefruit juice - The patient will soon find that their medication is not working and their symptoms to reappear.
True - Grapefruit is an inhibitor of CYP3A4.
Some CYP enzymes will increase metabolism, how will this affect the patient’s response to medication?
The patient will be at risk for being undertreated, cause their body will require more medication to be sufficient.
What enzyme places markers on proteins so that they can later be recognized and destroyed by lysosomes? Where are these found?
- phosphotransferase.
- Golgi apparatus.
_______ are formed due to dysfunctional phosphotransferase, causing lysosomes not to work. These cause fatal in childhood.
I-cell or Inclusion cells.
In what conditions, do we see fragmented Golgi apparatus?
- Alzheimer’s.
- Lou Gehrigs.
- Creuztfeldt jacob disease.
Primary lysosome:
- Buds off from golgi apparatus.
- Contains lytic enzymes.
Secondary lysosome:
- Site of digestion.
- Heterophagosomes - Do digestion of material from outside the cell.
- Autophagosomes - Do digestion of the cell and cellular content.
Post-digestive secondary lysosome:
- Residual bodies.
- Has lipofuschin granules that are called “wear and tear” pigment.
- Seen more in older people.
Which lysosomal disease causes an enlarged liver and heart, due to a deficiency of 1,4-glucosidase enzyme?
Pompe’s Disease.
Which lysosomal disease causes deformity of the CNS and skeletal system, resulting in gargoylism - Due to a deficiency of L-Iduronidase?
Hunter and Hurler Syndromes.
Tay-Sachs disease (lysosomal) causes gangliosidosis from deficiency of ___________ enzyme. It will affect the brain and eyes, and is fatal in childhood. There will will a build-up of _____________, and a lack of ______________
- Hexosaminidase.
- Build-up of gangliosides
- Lack of cerebrosides.
Which lysosomal disease will cause an enlarged spleen and anemia, caused by a deficiency of glucocerebrosidase enzyme.
Gaucher Disease.
Explain the difference between Niemann pick type A/B and type C.
- Niemann pick type A and B will have a deficiency of sphingomyelinase. While type C does not.
What is the function of the peroxisome:
- Oxidative enzymatic breakdown of toxins and organic compounds.
__________ is the enzyme used for the breakdown of hydrogen peroxide to H2O and O2. Can oxidize alcohol in the liver and kidney.
Catalase.
True or false: Oxidation of fatty acids will occur in the peroxisome, only when the fatty acid is too long to be processed by the mitochondria.
True.
How much of the bodies phospholipids are made up of plasmalogens? How much of the white matter?
- 20% of all phospholipids in the body are plasmalogens.
- Greater than 80% of all phospholipids in the white matter are plasmalogens.
Plasmalogens are a unique class of ____________________.
Glycerophospholipids.
Rhizomelic chrondroplaysia punctata follows what inheritance pattern?
Autosomal recessive.
Rhizomelic chrondroplaysia punctata type 1 is caused by:
A mutation in the PEX7 gene.
Neimann Pick Type C is associated with:
Cholesterol lipodosis.
Rhizomelic chrondroplaysia punctata type 2/3 is caused by:
Deficiency of peroxisomal enzymes involved in plasmalogen metabolism and synthesis.
What is the most severe peroxisome biogenesis disorder?
Zellweger syndrome.
What happens to peroxisomes during Zellweger syndrome?
Peroxisomes will have a large reduction, or become completely absent in the liver, kidney, and brain specifically.
Which mutation causes Zellweger syndrome?
Mutation in PEXR1 - Required for transport of peroxisome targeted enzymes.
Which leukodystrophy has manifestations of progressive demyelination and dysfunction of the adrenal cortex?
Adrenoleukodystrophy.
What inheritance pattern does adrenoleukodystrophy follow?
X-linked recessive.
What inheritance pattern does Zellweger Syndrome follow?
Autosomal recessive.
Mutation in the ABCD1 gene will impair transport of VLCFA’s, and cause what kind of leukodystrophy?
Adrenoleukodystrophy.
