Flashcards in Cell biology VI Deck (55):
What is the role of microtubule-associated proteins?
What is the diameter of a microfilament?
What are the subunits of microfilaments?
Actin subunits make up what cytoskeletal component?
What drug inhibits polymerization of actin?
What is the function of Cytocalasin B?
Prevents polymerization of actin subunits
What are the functions of microfilaments?
1) Structural support2) Form core of microvilli and stereocilia3) Cell movement4) Cytokinesis5) Formation of filopodia and lamellipodia
What is the diameter of thick filaments?
What are the subunits of thick filaments?
Myosin makes up which cytoskeletal component?
What is the diameter of intermediate filaments?
About 10 nm
Cytokeratins are what kind of cytoskeletal component?
Desmin is what kind of cytoskeletal component?
Where are cytokeratins localized?
Where is desmin localized?
Muscle (smooth and striated)
Glial fibrillary acidic proteins (GFAPs) are what kind of cytoskeletal component?
Where are glial fibrillary acidic proteins (GFAPs) localized?
Astrocytic glial cells
Neurofilament proteins are what kind of cytoskeletal component?
Where are neurofilaments localized?
Nuclear lamins are what kind of cytoskeletal component?
Where are nuclear lamins localized?
Nucleus of all cells
Vimentin is what kind of cytoskeletal component?
Where is vimentin localized?
Many mesodermal tissues
Mallory bodies are characteristic of what disease?
Alcoholic liver disease
Mallory bodies are made up of what type of intermediate filament?
Epidermolysis bullosa simplex is a disease characterized by lack of assembly of what intermediate filament?
What do cytokeratins form?
Vimentin is found in what cell types?
1) Fibroblasts2) Chondroblasts
GFAP aggregates are observed in what diseases?
1) Alexander disease2) Chronic gliosis3) Astrocytomas
What are Rosenthal's fibers?
Aggregations of GFAPs
Pathologists can determine tumor type based on what cytoskeletal component?
The centrosome (MTOC) conducts what microtubular processes / properties?
1) Number2) Polarity3) Direction4) Orientation5) Organization
What makes up the centrosome (MTOC)?
Two centrioles and an amorphous pericentriolar material
What is the arrangement of centrioles?
9x3 arrangement of microtubules
How are basal bodies formed?
Centrioles replicate to form procentrioles, which then become basal bodies
What are basal bodies required for?
Formation of microtubules associated with cilia and flagella
How is the centrosome involved in mitosis?
Formation of mitotic spindle
Are neoplastic cells with well-differentiated nuclei usually benign or malignant?
Are nuclei basophilic or acidophilic?
What are the components of the nucleus?
1) Nuclear envelope (double unit membrane)2) Nuclear matrix (nucleoplasm)3) Chromatin4) Nuclear bodies (domains)
What is the function of Cajal bodies?
Modification and assembly of molecular machinery to splice newly transcribed pre-mRNA into mRNA
What are GEMs?
Gemini of Cajal bodies
What is the cause of spinal muscular atrophy?
Mutation of survival of motor neurons (SMN) gene. SMN protein localizes to GEMs and causes death of motor neurons in anterior gray horns of spinal cord
What are PML bodies and what do they do?
1) Promyelocytic leukemia bodies2) Modify and assembly proteins involved in DNA repair and triggering of apoptosis
What is the diameter of a nuclear pore?
How many subunits make up a nuclear pore?
What is the diameter limit for freely permeable molecules and ions passing through the nuclear pore?
The nuclear pore selectively transports what molecules?
1) RNA2) Ribosomal subunits3) Proteins4) Other molecules and ions
What are the functions of the nuclear lamina?
1) Supports inner nuclear membrane2) Disassembly of nuclear envelope during prometaphase - lamins are phosphorylated3) Reassembly of nuclear envelope during telophase - lamins are dephosphorylated
During disassembly of the nuclear envelope in prometaphase, are lamins phosphorylated or desphosphorylated?
During reassembly of the nuclear envelope in telophase, are lamins phosphorylated or desphosphorylated?
Mutations in the nuclear lamina are associated with what diseases?
1) One form of muscular dystrophy2) Two forms of progeria
What is the basic structural unit of chromatin?
Is heterochromatin transcriptionally active or inactive?