Cell Organelles Flashcards
4 compartments of the eukariotic cell?
plasma membrane nucleus cytoplasm Endoplasmic ER (smooth and rough) Golgi apparatus mitochondria lysosomes peroxisomes
In liver hepatocytes vs. pancreatic exocrine cells, compare the number of rouch ER and mitochondria inner membrane to each
Rough ER: 60 in pancreatic exocrine
Mitochondria inner membrane 32 in liver hepatocyte
the cell is divided into what 3 topological catefoires
- nucleus and cytosol 2.Golgi apparatus, endosomes, lysosomes, ER
- Mitochondria
Membrane ___ and ___ allows the lumen of these compartments to communicate with each other and with the ______.
budding
fusion
cell exterior
Cells that make ___ proteins have lots of RER.
secreted
RER = rough ER
The signal sequence does what with regards to secretory proteins?
direct the mechanism of secretory proteins in the ER
Lots of smooth ER in what
cells that make steroids or lips
how do proteins exit the RER?
in vesicles, transported to the cis portion of the golgi apparatus
Cis side faces where?
Trans?
of the golgi apparatus
cis adjacent ot ER
Trans facing towards plasma membrane or nucleus
golgi apparatus does what
modify carbs by attached to glycoproteins and proteoglycans
makes also: polysaccarides, oligosaccharides, sphingomyelin, glycosphingolipids
packaging and storing secretory porducts into secretory vesicles
vesicles transporitng stuff form golgi to lysosome are coated in what?
COP-coated vesicles are good for what
Clathrin, a protein that uses dynamin thats in clathrin-coated pits at the plasma membrane. Helps the neck of vesicle pinch into plasma mebrane
transport btwn stacks in golgi or from ER to golgi (COPII)
What mediate clathrin binding to the vesicle membrane?
adaptins
lysosomes are the ____ system of the cell
recycle
lysosomes contain what
very active and acidic hydorlitic enzymes that break down carbs, proteins, lipids, nucelic acids
How do lysosomes maintain their acidic intralysosomal environment?
ATP-dependent H+ pumps to make it a pH of 5
pathway for lysosomal sorting
- lysosomal nzymes getseparated other glycoproteins in vesicles with the M6P receptor. Lysosomal enzymes are activated via phsophorylation.
- lysosomal nzymes dissociate from teh M6P repctor acfter being transported to a clathrin-coated transporting vesicle. They become surroudned by a membrane to form a primary lysosome.
Primary vs. secondary lysosomes
primary: storage site of lysosomal hyrolyase, with no digrestive events, inactivated enzymes
secondary: lysosomes are engaged in catlaytic processes, with digetstive enzymes active
3 pathways for intracellular degradation
phagocytosis
autophagy
receptor-mediated endocytosis
____ are precursors of secondary lysosomes
Late endosomes
What’s a change seen in endosome maturation?
Lowering of internal pH 5.5
What causes familial hyper cholesterolemia?
Elevated LDL
Mech. Of cholesterol uptake is disrupted, bc gene encoding for LDL receptor is mutated
LDL elevated = atherosclerotic plaques
Peroxisomes have enzymes that make hydrogen peroxide. What breaks down this damaging molecule?
What else happens in this organelle
Catalase
Beta oxidation if VLCFA
Bike/cholesterol synth
Detoxify alcohol
Zellweger spectrum disorder?
Peroxisome assembly is defected
____ and ____ originated from bacteria
Mitochondria
Chloroplast
Similar in inner/outer membrane and stacks (Christa’s/thylakoids)
Adapt to generate and harness energy
Retain their own DNA
Mitochondria can be dynamic and less dynamic. How?
Dynamic: assoc with microtubule cytoskeleton
Fixed: pack tightly btwn myofibrils(cardiac muscle) and around flagellum in sperm
Over 200 disease have been linked to ___ mutations, which often prevent aminoacation to these. Mt disease can arise from what else?
Mitochondrial tRNA (mt tRNA) Aninoaclation of tRNA
Mutations in mt DNA that affects mitochondrial function or gene products imported in at mt proteins
