Cellular Structures Flashcards
The cell is divided into what tree topological categories?
Nucleus and cytosol
Organelles in secretory and endocytic pathways
Mitochondria
The ER divides the cytoplasm in what?
Two compartments:
Luminal or cisternal compartment
Cystoplasmic or cytosolic compartment
What are the important functions of the SER?
Glycogen metabolism Lipid synthesis Phospholipid synthesis Detoxification Steroidogenesis Calcium regulation
*abundant in cells that make steroids or lipids
What are the functions of the Golgi?
modification of carbs attached to glycoproteins and proteoglycans
Polysaccharide and oligosaccharide synthesis
Synthesis of sphingomyelin and glycosphingolipids
Sorting secretory products: M6P
Packaging and sorting secretory products into secretory granules or vesicles
What surronds the neck of the invaginated coated pit, causing the neck of the vesicle to pinch off from the plasma membrane?
Dynamin
What are adaptins?
they mediate clathrin binding to the vesicle membrane
What does dynamin-2 participates in?
synaptic vesicle recycling, post-synaptic receptor internalization, neurosecretion, and neuronal process extension
When there is a mutation in the dynamin-2 gene, it results in what two congenital neuromuscular disorders?
Charcot-Marie-Tooth disease: affects myelination and peripheral nerve conduction
Centronuclear Myopathy: progressive and generalized atrophy of skeletal muscles. Abnormalities in nervous system
What have single nucleotide polymorphisms located in the dynamin-2 gene been associated with?
sporadic Alzheimer’s disease
How do lysosomes maintain an acidic intralysosomal environment?
ATP-dependent H pump
What disease is characterized by elevation of LDL, the predominant cholesterol transport protein in the plasma and the primary defect is mutation in gene encoding the LDL receptor?
Familial hypercholesterolemia
What do peroxisomes contain?
enzymes that form hydrogen peroxide which is immediately broken down by catalase
What are the functions of peroxisomes?
Synthesis and degradation of hydrogen peroxide
Beta-oxidation of long-chain fatty acids
Bile acids and cholesterol synthesis
Detoxify alcohol
What causes zellweger spectrum disorder?
Defects in the assembly of the peroxisome
any one of the 12 genes defected resutls in the disorder
Most serious case has an absence or reduced number of peroxisomes in the cells
Present at birth, no cure or treatment
