| Question/Term | Answer/Definition |
| Properties of Intermediate Filaments | Polarity: None
Functions:
-Structure
-Shape
-Formation of nuclear lamina and scaffolding
-Strengthening of nerve cell axons
-Keeping muscle fibers in register |
| Properties of Microtubules | Monomers: Alpha-Tubulin and Beta-Tubulin
Polarity: +/- ends
Functions:
-Organization of share and polarity
-Chromosome movements
-Intracellular transport
-Cell motility |
| Elements of the Cytoskeleton | 1. Microtubules (MTs)
2. Microfilaments (MFs)
3. Intermediate filaments (IFs) |
| Properties of Microfilaments | Monomers: G-actin
Polarity:
+/- ends
Functions:
-Muscle contraction
-Cell locomotion
-Cytoplasmic streaming
-Cytokinesis
-Shape and transport |
| Types of Microtubules | 1. Cytoplasmic
2. Axonemal |
| Bacterial-Tubulin Equivalent | Ftz |
| Bacterial Intermediate Filament Protein Equivalent | Crescentin |
| Protofilament, Heterodimer, Tubulin Monomers | Protofilament: The whole heterodimer and monomer(alpha or beta monomers) all together.
Heterodimer: Alpha and Beta monomers.
Monomer: An alpha or Beta particle. |
| Bacteria Actin Equivalent | MreB |
| Vinblastine and Vincristine | -Affect MTs
-Aggregate tubulin heterodimers |
| Phallodin | -Affects MFs
-Binds and stabilizes assembled MFs
- (+) No polymerization
- (-) No depolymerization |
| Taxol | - Affects MTs
- Stabilizes MTs
- (+) No polymerization
- (-) No depolymerization
-Everything is stable. |
| Latrunculin A | - Affects MFs
- Sequesters actin monomers
"JAIL" (Puts monomers separately in a corner or "jail" to keep from polymerizing. |
| Microfilament Actins | - G-actin
- F-actin
- G-actin: Monomers of F-actin
- F-actin: Polymerized G-actin which form filaments. |
| Cytochalasin D | - Affects MTs
- Prevents addition of new monomers to plus ends ("thinks plus end is ugly and won't hook up with it") |
| Colchicine Colcemid | - Affects MTs
- Binds tubulin monomers, inhibiting self assembly (binds to both/either alpha or beta monomers and won't let them polymerize). |
| Nocadazole | - Affects MTs
- Binds to Beta-tubulin, inhibiting polymerization (thus will not allow the monomers to bind). |
| Singlet MTs | - 13 profilaments
- Cytoplasmic MTs |
| Doublet MTs | - One of the 13 protofilament part and one additional incomplete 10 or 11 protofilament part.
- Ex: Cilia and flagella |
| Triplet MTs | - One 13 protofilament part and two additional 10 or 11 protofilament parts.
- Ex: Basal bodies and centrioles |
| Microtubule Nucleation | - When oligomers (groups of aggregated tubulin heterodimers) form nuclei from which MTs grow. |
| Microtubule Elongation | - The stage in which nucleated MTs grow by the addition of subunits at either end. |
| MT Lag Phase | Nucleation |
| MT Elongation Phase | - Tubulin heterodimers are added to the nucleated MT and it grows. |
| MT Plateau Phase | - MT assembly and disassembly are balanced. |
| MT Critical Concentration | - The tubulin heterodimer concentration at which MT assembly is exactly balanced with disassembly. |
| MT Plus End | - The rapidly growing end of the MT. |
| MT Minus End | - The slowly growing end of the MT
OR
- The depolymerizing end when the critical concentration is reached for the plus end, but not the minus end. |
| Treadmilling | - When a given tubulin molecule incorporated at the plus end is displaced progressively along.
-The MT eventually are lost by depolymerization at the opposite end. |
| MAPs | -MT-associated proteins.
-MAPs increased MT stability and can affect the density of bundles of MTs.
-Tau: Causes MTs to form tight bundles in axons.
-MAP2: Causes the formation of looser bundles of MTs. |
| Tau | Causes MTs to form tight bundles in axons. |
| MAP2 | Causes the formation of looser bundles of MTs. |
