CB 5 Flashcards
MERRF- Myoclonic epilepsy with ragged red fiber
- red appearing mitochondria
- Gomori trichrome stain
- ragged red fiber appearance to muscle fiber
- parking lit inclusion in mitochondrion
- symptoms: myoclonus, seizures, ataxia
functions of perioxisomes
- b oxidation of free fatty acids
- plasmalogen synthesis
- regulate H2O2
- kill pathogens
- oxidize EtOH
Zellweger syndrome
impaired import of enzymes into peroxisomes, defective import protein on the unit membrane of the peoxisome
cytoskeletal elements
- microtubules
- filaments
Filaments
- actin= thin
- intermediate
- myosin= thick
kinesine
microtubule motor
botulinum toxin
works by proteolysis of SNARE proteins
coated vesicles
clathrin
COPII
COPI
COPII
anterograde transport from ER to cis golgi network
COPI
retrograde transport from cis golgi network aka CGN
retrograde transport is needed for….
returning membrane v SNARE proteins and missorted ER proteins back to the ER
Vesicle snare [vsnare]
recognize target SNAREs
SNARE proteins
allow vesicle to recognize its target domain
Tetanus and Botulism
enter nerve terminals and proteolyze SNARE proteins, prevents vesicles containing neurotransmitters to release them
Mitochondria
- acidophillic organelle
- located in areas of high metabolic activity
- erythrocytes don’t have any mitochondria
Composition of mitochondria
- mainly protein
- lipid
- small amts of RNA and mtDNA
- *most mitochondrial proteins are synthesized by free polyribosomes in the cytoplasm and are actively transported in by translocator proteins
Outer membrane of mitochondria
- fairly permeable, large channel forming proteins
- translocator protein
Inner membrane of mitochondria
- selectively permeable
- decreased permeability due to presence of high conc of cardiolipin
- contains enzymes for ETS
- contains translocator proteins
CO and Cyanide
block the ETS
Intermembrane space of mitochondria
between the inner and outer mitochondrial membranes
shelf like cristae
located in mitochondria
seen in hepatocytes and cardiac/skeletal muscle
tubular cristae
found in:
steroid secreting cells
intracristal space
is continuous with the intermembrane space
Mitochondrial Maxtrix composition
enzymes for Krebs cycle
enzymes for fatty acid b oxidation
matrix granules
Cytochrome c
release of this activates the apoptotic mechanism
mutations in mitochondrial DNA
-diabetes, deafness, heart disease, alzheimers, parkinsons, LHON
Peroxisomes
- contain oxidative enzymes for fatty acids
- catalase: forms water and oxygen from hydrogen peroxide
- oxidation of ingested ethanol
- synthesis of plasmalogens!
lipitor
leads to increased uptake of triglycerides and cholesterol, causes an increase in peroxisomes
plasmalogen defects
lead to abnormalities of myelination in nerve cells
Drugs that inhibit polymerization of microtubules
colchine, vinblastine, vincristine
Taxol
inhibits depolymerization of microtubules
Functions of microtubules:
- support to the cytoplasm for cell shape
- organelle support
- cell division
- motility of cilia and flagella
- long range transport of vesicles by microtuble motor proteins
Microtubule motors
- kinesin
- dyein
Kinesin
- motor towards the periphery
- defect causes decrease transport of serotonin receptors
- may cause anxiety disorders
Dynein
motor that goes towards the nucleus from positive to negative end
