Term
| • The cytoskeleton is required for... |
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Definition
structural strength and motility of eukaryotic cells.
cytoskeleton functions in a cell- and tissue-specific context |
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Term
| T/F Prokaryotes contain some type of cytoskeleton |
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Definition
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Term
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Definition
o Microfilaments
o Intermediate filaments
o Microtubules
o Motor proteins
o Supporting fibers |
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Term
| basic monomer of microfilaments is |
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Definition
| G-actin, which can polymerize to form F-Actin |
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Term
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Definition
| • Themicro filament is polar with most of the growth occurring at the positive end (addition of G-actin-ATP), and most of the dissociation occurring at the negative end (G-actin-ADP) |
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Term
| • Proteins that regulate actin microfilaments |
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Definition
o Gelsolin
o Tropomodulin
o Myosin
o Tropomyosin
o Profilin |
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Term
| • Microfilaments are involved in a number of cellular processes, including: |
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Definition
o Phagocytosis
o Muscle contraction
o Contraction of intestinal microvilli
o Amoeboid motility
o Outgrowth of dendrites/axons in neuroblasts
o Mitosis |
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Term
| Function of intermediate filaments |
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Definition
mechanical/structural support to cells
polymers of different subunits |
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Term
| o Intermediate filaments are polymers of a number of different subunit proteins, which are.... |
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Definition
• Lamin
• Desmin
• Peripherin
• Alpha-Internexin
• Keratin - can be inside the cell (cytokeratin) or external to the cell
• Vimentin
• Neurofilament
(there are also variations of these subunit proteins) |
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Term
| Explain how the variant subunit proteins contribute to the overall stability and lack of charge in intermediate filaments |
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Definition
• The monomeric protein subunits form dimers
• The dimers form tetramers
• The tetramers form the protofilament
• The protofilament forms the intermediate filament
• The overall intermediate filament structure is stable, and has no polarity |
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Term
| o Genetic keratin (intermediate filament) disorders include |
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Definition
• Epidermolysis bullosa
• Epidermolytic hyperkeratosis |
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Term
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Definition
a group of skin blistering diseases
EB is transmitted as an autosomal dominant trait, caused by mutations in keratin genes expressed in epidermal basal cells
CAN BE LETHAL |
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Term
| Epidermolytic hyperkeratosis |
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Definition
| a disease characterized by blistering, scaling, and hyperkeratosis |
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Term
| Formation of Microtubules |
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Definition
| alpha & beta monomers → heterodimers → linear protofilaments → 13 protofilaments → Array → microtubule |
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Term
| • Microtubules are involved in |
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Definition
maintenance of cell shape and intracellular transport process
includes mitotic alignment of chromosomes and transport of vesicles |
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Term
| Name drugs that bind to microtubules and interfere with either assembly or disassembly.... |
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Definition
• Colchicine
• Vinblastine/Vincristine
• Taxol
• Griseofulvin
o Interference with either assembly or disassembly can interfere with polymerization process and can inevitably kill the cell |
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Term
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Definition
treatment of gout
affects cells of the immune system |
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Term
| • Vinblastine/Vincristine |
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Definition
treatment of certain cancers
cancers need microtubules for growth (periwinkle) |
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Term
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Definition
treatment of certain cancers
breast cancer…found a way to synthesize the materials without out cutting down trees |
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Term
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Definition
| treatment of fungal infections |
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Term
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Definition
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Term
| Cilia and flagella are made of... |
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Definition
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Term
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Definition
• Inner structures of cilia and flagella
consist of nine microtubule doublets around periphery and two microtubule singlets in center |
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Term
| T/F Microtubules of cilia and flagella are dynamic structures undergoing rounds of polymerization-depolymerization |
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Definition
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Term
| • Ciliated cells can be found... |
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Definition
| found in respiratory tract and in female reproductive system (microvilli are not considered to be cilia) |
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Term
| • The only flagellated cell in the human |
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Definition
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Term
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Definition
| a motor protein, moves adjacent microtubules, leading to axoneme bending. Motion of dynein is powered by hydrolysis of ATP |
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Term
| • Immotile cilia syndrome |
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Definition
rare heterogenous genetic disorder characterized by defects in dynein arms and associated structures
Patients are prone to frequent respiratory infections, while male patients (and sometimes female patients) are infertile.
About ½ of all individuals who have immotile cilia syndrome have complete situs inversus |
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Term
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Definition
o left internal organs are on the right part of the body, and right on the left
o Cilia may be involved in polarity and moving things around |
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Term
| • Penrose-Hammeroff Hypothesis |
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Definition
Consciousness
Claims it begins in the microtubules of the brain
Polymerization generates consciousness |
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Term
| explain Integration of cytoskeleton with membrane |
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Definition
| Alpha and beta spectrin → ANTIPARALLEL dimer → long tetramer → attached to actin filaments (in erythrocytes) → tetramer interacts with membrane integral proteins |
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Term
| Membrane integral proteins that spectrin tetramer interacts with |
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Definition
o Glycophorin
• RBC and also has become the receptor for malaria
o Sialoglycoprotein
• Nana connection (glycoprotein) |
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Term
| o Hereditary spherocytosis |
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Definition
| a heterogenous group of genetic diseases caused by mutations in the genes coding for spectrin or associated actin-binding proteins |
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Term
| common denominator of spectrin-related disorders |
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Definition
| a reduced amount of spectrin, as free spectrin is subject to proteolytic degradation. |
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Term
| o Hereditary spherocytosis is transmitted as an a_________ trait, with a prevalence of ___________, in NW Europe. |
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Definition
autosomal dominant trait
1/5000 NW Europe |
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Term
| How does Hereditary spherocytosis lead to hemolytic anemia? |
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Definition
The disease is manifest as small, round erythrocytes, which are destroyed in the spleen, leading to hemolytic anemia.
• One job of the spleen is to get rid of RBC
• Results in anemia caused by the body |
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Term
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Definition
| mutations in the dystrophin gene, a relative of spectrin |
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Term
| dystrophin (relative of spectrin) |
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Definition
forms antiparallel dimers and binds to a set of membrane proteins
localized under the plasma membrane and is involved in the interaction of the cytoskeleton with the extracellular matrix |
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Term
| • Unlike spectrin, dystrophin is found primarily in ........ |
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Definition
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Term
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Definition
very large, containing 79 exons, and a high rate of mutation
novel mutations
located on the X chromosome
1 in every 4000 males |
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Term
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Definition
| started in the offspring….but the tendency for the gene to mutate is transmitted |
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Term
| Duchenne muscular dystrophy (more severe form) |
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Definition
| disorder that usually leads to death at about age 20 on account of cardiac or respiratory failure. |
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Term
| Becker muscular dystrophy |
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Definition
| a milder form of the disease, allows survival into adulthood |
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Term
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Definition
| involved in the movement of intracellular membranes and organelles to the actin cytoskeleton |
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Term
| Mutation in the Myosin VII-A gene |
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Definition
involved in generating Usher’s Disease
o the most frequent cause of deaf-blindness in humans
o Cause is not clear |
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Term
| • Charot-Marie-Tooth Disease |
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Definition
progressive neuropathic muscular atrophy
mutation in the nuclear lamina (a fibrillar network inside the cell nucleus, composed of intermediate filaments and membrane associated proteins) can cause |
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Term
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Definition
| – disease of the nervous system |
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Term
| Hutchinson-Gilford Progeria Syndrome |
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Definition
mutation in Lamin A (a component of the nuclear lamina) can cause
• Disease of accelerated aging
• Normal intellectual development
• Distinct facial features
• Alopecia
• Joint abnormalities
• Probably result from issue with the nuclear envelope, which is part of the cytoskeleton |
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Term
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Definition
| diseases associated with the cilia |
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