Exam #1: Cell Biology V Flashcards
COPI
- Coating-Protein I
- Golgi (Trans)–>ER
- Retrograde
COPII
- Coating Protein II
- ER–> Golgi (Cis)
- Anterograde
Clathrin
- Plasma membrane into the cell
- Trans Golgi–> out of the cell
SNAREs
Mediate vesicular transport by recognizing one another
t-SNARE
- Target SNARE
- Allows the vesicle to recognize its target domain
v-SNARE
- Vesicular SNARE
- E.g. synaptotagmin & Synaptophysin
What is the function of retrograde transport?
- Maintain membrane balance
- Transport of SNARE proteins back to ER
- Correction of Mis-sorting/ Delivery
What is the role of SNARE proteins in neurotransmission?
- Secretory vesicle recognition
- Release of NT
Botulinum Toxin
- Eliminates t-SNARE (proteolysis)
- Prevents neurotransmission/ NT release
- Causes paralysis of muscle
What are the two organelles that have two plasma membranes?
- Mitochondrion
- Nucleus
Cristae
- Foldings of the mitochondrion
- Contain ATP Synthase & enzymes of oxidative phosphorylation
What can you tell about a mitochondrion that has a large number of cristae vs. a cell that has few cristae?
More cristae= produces more ATP/ has a higher ATP need
What cell type has no mitochondria?
RBC
Mitochondrial Matrix
- Space that the cristae project into
- Contains matrix granules
- Contains mitochondrial DNA
- TCA cycle enzymes
- Beta-oxidation enzymes
Outer Mitochondrial Membrane
More permeable
Inner Mitochondrial Membrane
- Less permeable
- Control the hydrogen ion gradient
- Electron transport, ATP synthase…etc. contained here
- CO & cyanide poisoning
What two organelles are involved in the synthesis of steroid hormones?
- Mitochondrion
- sER
What five complexes are involved in the transport of proteins into the mitochondria?
- TOM
- TIM 22
- TIM 23
- SAM
- OXA
What confers acidophilic striations at the light microscope level?
- Mitochondria in palisades (picket-fence)
- Very abundant mitochondria involved in hydrogen ion transport
Tubular Cristae
Hallmark features of mitochondria that are associated with steroid hormone synthesis
- Testis, ovaries, adrenal cortex
- Closely associated with lipid droplets containing cholesterol
How is the synthesis of steroid hormones described?
Ping-pong process
MERRF
- Myoclonic Epilepsy with Ragged Red Fibers
- Mitochondrial Disorder
- Light microscope= red mitochondira w/ Gomori Trichrome Stain
- EM= “parking lot” inclusion
- Symptoms include involuntary jerking/ twitching, seizures, & gait disturbances
- Maternally inherited
Myoclonus
- Hiccups
- Sleep Jerk
What happens to the shape of the mitochondria in response to alcoholic cirrhosis?
Odd-shaped in response to injury
What are the functions of the peroxisome?
1) Beta-oxidation of FFAs
2) Plasmalogen Synthesis
3) Regulate Hydrogen Peroxide
4) Kill Pathogens
5) Oxidize Ethanol
Plasmalogens
- Abundant type of phospholipid found in myelin
- Very important for development
Zellweger Syndrome
- Disease state caused by defective import of peroxisomal enzymes
Thin Filaments
- Actin
-
Intermediate Filaments
- Very diverse class of cytoskeletal elements
Thick Filaments
- Myosin
Microtubule
- Hollow structure
- Made of tubulin dimers that polymerize
- Can exist independently in the cytoplasm
- May assemble into doublets
Dynein
- ATPase associated with microtubules
- Allows microtubules to be motile and become cilia & flagella
- Also microtubule motor that transports material from the positive end to the negative end
What are the functions of microtubules?
1) Support the cytoplasm
2) Organelle Support
3) Cell division
4) Motility of cilia & flagella
5) Long-range transport of vesicles
Kinesin
- Microtubule motor
- Transports from negative end (nucleus) to positive end
- E.g. neurotransmitters
