Term
| Why do different cell types have different shapes? |
|
Definition
| To fulfill important roles they have to play in the body |
|
|
Term
| How do a cell's shape arise? |
|
Definition
| Through the regulated assembly and disassembly of the cytoskeleton. |
|
|
Term
| What do the microvilli do? |
|
Definition
| increase the surface area of the digestive system for the better absorptions of nutrients |
|
|
Term
| The key to generating different types of cell shapes is the ability to ____ ____ within the cell. This property is ofter called ____. |
|
Definition
|
|
Term
| Cellular polarity arises because the structural elements responsible for cell shape are ____ structures |
|
Definition
|
|
Term
| The three key cytoskeletal structural elements are? |
|
Definition
| microtubules, actin filaments, and intermediate filaments |
|
|
Term
|
Definition
|
|
Term
|
Definition
| Microtubules (alpha-Beta Tubulin dimer) |
|
|
Term
|
Definition
|
|
Term
| Actin is organized into what by actin binding proteins? |
|
Definition
|
|
Term
| Actin is especially important for the organization of the ____ ____ |
|
Definition
|
|
Term
| Actin can serve as a track for myosin to generate _____ forces or to move ____ |
|
Definition
|
|
Term
| Mircotubules provide a what? |
|
Definition
|
|
Term
| What makes up the mitotic spindles, for chromosome duplication at mitosis? |
|
Definition
|
|
Term
| Mircotubules are tracks for organelle transport by the motors ____ and ____? |
|
Definition
|
|
Term
| Intermediate filaments provides structural support to the ___ ___, structural integrity in ____, and structural and barrier functions in ___, ____, and ____ |
|
Definition
| nuclear membrane, tissues, skin, hair, and nails |
|
|
Term
|
Definition
|
|
Term
| Microtubules make up the? |
|
Definition
|
|
Term
| Intermediate filaments are similar to actin but do not provide? |
|
Definition
|
|
Term
| What is marked by a lag period in which G-actin subunits combine into short, unstable oligomers? |
|
Definition
|
|
Term
| When an oligomer reaches ___ subunits it becomes a "stable seed" or "nucleus" |
|
Definition
|
|
Term
| What phase is the period when there is rapid increase in filament length by the addition of actin monomers to both ends? |
|
Definition
|
|
Term
| As F-actin filaments lengthen, the concentration of G-actin decrease until ___ ____ is reached |
|
Definition
|
|
Term
| At steady state, G-actin exchanges with F-actin but there is no change in the concentration of either. The concentration of G-actin at this point is called the ____ ____ |
|
Definition
|
|
Term
| The pointed end of myosin is what sign? The barbed end? |
|
Definition
|
|
Term
| What end of myosin is there a lot of polymerization? |
|
Definition
|
|
Term
| At steady state treadmiling occurs as a result of ____ ____ by actin filaments |
|
Definition
|
|
Term
| At steady state, the ___ end lengthens and the ___ end shortens in a process called treadmilling |
|
Definition
|
|
Term
| What blocks protein assembly and disassembly at actin filament plus ends? |
|
Definition
|
|
Term
| CapZ is made of up of two subunits. It has high affinity binding to the ___ end of actin filaments |
|
Definition
|
|
Term
| The rate limiting step in actin assembly is the ____ phase |
|
Definition
|
|
Term
| The ___ ____ is where assembly and disassembly are balanced |
|
Definition
|
|
Term
| When ATP-G actin concentration is above the critical concentration the filament ___. When less it ___ |
|
Definition
|
|
Term
| ATP-G actin adds faster at the ___ end than the ___ end |
|
Definition
|
|
Term
| ___ ____ controls actin dynamics by changing the confirmation of actin |
|
Definition
|
|
Term
| At ___ ___, actin subunits treadmill through filaments |
|
Definition
|
|
Term
| ATP-G actin binds the ___ end, ATP is then hydrolyzed to ADP and Phosphate. The phosphate is then lose and eventually ADP actin dissociates from the ___ end |
|
Definition
|
|
Term
| Actin dynamics are regulated by ___ ___ ___ |
|
Definition
|
|
Term
| ___ binds actin monomers and increase the rate of ADP-ATP exchange |
|
Definition
|
|
Term
| ____ binds to ATP-G actin and acts as a "buffer" |
|
Definition
|
|
Term
| ____ destabilizes F-actin |
|
Definition
|
|
Term
| ___ binds to the plus end of actin filaments and blocks assembly |
|
Definition
|
|
Term
| ____ blocks actin assembly and disassembly at the actin filament minus end |
|
Definition
|
|
Term
| The ____ dimer binds two actin subunits and by rocking back and forth it allows additional subunits to be added |
|
Definition
|
|
Term
| The ____ domain protects the plus end of the actin filament from CapZ |
|
Definition
|
|
Term
| What do you need to add to cells to increase the rate of polymerization of actin when comparing it to just adding more actin? |
|
Definition
|
|
Term
| What are the regions of the growth cone? |
|
Definition
| Central domain (rich in microtubules), Peripheral domain (rich in actin), and within the P-domain the lamellipodia is a broad veil, and the filopidia are fingerlike extensions |
|
|
Term
| The assembly of unbranched actin filaments is driven by ___ |
|
Definition
|
|
Term
| Formin has a regulatory ___ domain that is rich in proline and binds to profilin |
|
Definition
|
|
Term
| What are the Rho family GTPases that regulate actin assembly? |
|
Definition
| Rho, Rac, cdc-42, and Rif |
|
|
Term
| What regulates formin in filopida? |
|
Definition
|
|
Term
| What regulates formin in stress fibers? |
|
Definition
|
|
Term
| What regulates ARP2/3 via WASp |
|
Definition
|
|
Term
| What binds to the sides of actin filaments to form new branches? |
|
Definition
|
|
Term
| What is the difference between classes II and V in the myosin F-actin motors? |
|
Definition
| The step sizes, class V is larger than II and V has two heads that go arm over arm, while II just grabs and pulls. V moves things over long distances (velocity) and II is used for force generation |
|
|
Term
| What are the six myosin II polypeptides? |
|
Definition
| 2 heavy chains and 4 light chains |
|
|
Term
| What happens in rigor mortis? |
|
Definition
| ATP is absent in the muscles so myosin binds tightly to the f-actin |
|
|
Term
| What moves myosin into its "cocked" state? |
|
Definition
|
|
Term
| What creates the power stroke in myosin? |
|
Definition
|
|
Term
| Myosins with ___ lever arms move at higher velocities |
|
Definition
|
|
Term
| What are the two types of filaments in sarcomeres? |
|
Definition
| Thin filaments made of actin and thick filaments made of myosin |
|
|
Term
| What end of actin filaments are embedded in the z-disks? |
|
Definition
|
|
Term
| What stabilizes the plus end of the actin filaments? |
|
Definition
|
|
Term
| What stabilizes the minus end of the actin filaments? |
|
Definition
|
|
Term
| What keeps the myosin filaments aligned in the middle of the sarcomere? |
|
Definition
|
|
Term
| What controls the length of the actin filaments? |
|
Definition
|
|
Term
| What in the presence of ATP leads to contraction of the muscles? |
|
Definition
|
|
Term
| High calcium causes a change in the confirmation of ____ and ____. |
|
Definition
|
|
Term
| In normal cells, there is a ____ flow of F-actin in the lamellipodia |
|
Definition
|
|
Term
| Addition of ____ blocks the assembly of new actin at the ples ends of acitn filaments, but does not block retrograde flow. |
|
Definition
|
|
Term
| ____ is a drug that inhibits myosin II. Its addition, slows but does not stop retrograde flow. Thus myosin makes a partial contribution to retrograde flow |
|
Definition
|
|
Term
| Addition of both ____ and ____ slows retrograde by 80% thus we can conclude both actin polymerization and myosin both contribute to retrograde flow |
|
Definition
| Cytochalasin, blebbistatin |
|
|
Term
| Microtubules can treadmill using the energy of ___ ___? |
|
Definition
|
|
Term
| Individual microtubule plus ends can undergo dynamic instability, with alternating periods of ___ or rapid ___ |
|
Definition
|
|
Term
| Growing microtubules are capped with ___ where shrinking ends have ___ |
|
Definition
| GTP-beta-tubulin, GDP-beta-tubulin |
|
|
Term
| Microtubules are stabilized by ___ binding ___ such as tau. |
|
Definition
|
|
Term
| Other proteins can bind microtubules and induce ___ |
|
Definition
|
|
Term
| What binds to the plus end of actin filamnets and block polymerization? Like Cap-C |
|
Definition
|
|
Term
| What binds to G-actin and blocks polymerization? |
|
Definition
|
|
Term
| What binds along F-actin and blocks depolymerization? |
|
Definition
|
|
Term
| What inhibits myosin II. Myosin light chain phosphatase? |
|
Definition
|
|
Term
| What is important for denetric organization? |
|
Definition
|
|
Term
| How many rings does a singlet have? |
|
Definition
|
|
Term
| How many rings does a doublet have? |
|
Definition
|
|
Term
| How many rings does a triplet have? |
|
Definition
|
|
Term
| The doublet structures are in what? |
|
Definition
|
|
Term
| The triplet structures are in what? |
|
Definition
| Basal bodies and centrioles |
|
|
Term
| What does MTOC stand for? |
|
Definition
| Microtubule Organizing Center |
|
|
Term
| What is the MTOC that nucleates the radial array of microtubules in nonmitotic cells? |
|
Definition
|
|
Term
| What consists of two centrioles and a pericentriolar material that contains the gamma-TURC microtubule nucleating complex? |
|
Definition
|
|
Term
| What are the two drugs that affect tubulin polymerization that have been used to treat cancer? |
|
Definition
|
|
Term
|
Definition
| Microtubule associated proteins |
|
|
Term
| What are the type I MAPs? |
|
Definition
|
|
Term
| What are the types II MAPs? |
|
Definition
|
|
Term
| Which MAP has a longer projection arm? |
|
Definition
|
|
Term
| MAPs can coat the outer microtubule wall and promote growth or suppress___ |
|
Definition
|
|
Term
| Activity of MAPs regulated by ___ ___ of projection domains. |
|
Definition
| reversible phosphorylation |
|
|
Term
| Phosphorylation promotes microtubule ___ |
|
Definition
|
|
Term
| What are examples of phosphorylating agent? |
|
Definition
|
|
Term
| What are the 3 known mechanisms for regulating microtubule disassembly? |
|
Definition
| Kinesin-13, Stathmin/Op18, and Katanin |
|
|
Term
| What kind of transport is plus end directed from cell body towards synapse? |
|
Definition
|
|
Term
| What kind of transport is minus end directed from synapse towards cell body? |
|
Definition
|
|
Term
| What is the anterograde motor? |
|
Definition
|
|
Term
| What is the retrograde motor? |
|
Definition
|
|
Term
| What are the 3 things dynactin binds? |
|
Definition
| microtubules, dynein, and cargo |
|
|
Term
| Is dynein or kineisn more active on the golgi? |
|
Definition
|
|
Term
| Defects in what cause diseases such as Hutchison-Gilford Progeria? |
|
Definition
|
|
Term
|
Definition
| centrosomes, spindle fibers, basal bodies |
|
|
Term
| Inside cilia and flagella is a microtubule-based cytoskeleton called the? |
|
Definition
|
|
Term
| What is important for regulating the axoneme is the ring structures? |
|
Definition
|
|
Term
| What joins adjacent outer doublet and also radial projections from A tubule towards central pair? |
|
Definition
|
|
Term
| What is attached down the length of each A tubule in 2 rows- inner and outer? |
|
Definition
|
|
Term
| What does axonemal dynein induce? |
|
Definition
| controlled sliding of outer doublet microtubules |
|
|
Term
|
Definition
|
|
Term
| What moves up and down in the cilia and flagella? |
|
Definition
|
|
Term
| What powers anterograde transport? |
|
Definition
|
|
Term
| ____ dynein mediates retrograde transport |
|
Definition
|
|
Term
| What are the three classes of microtubules in the mitotic spindle? |
|
Definition
| Polar (from pole to pole), astral (from pole to cell cortex), and kinetochore (poles to kinetochore) |
|
|
Term
| What depolymerizes at the minus ends, it pulls the microtubules to the poles? |
|
Definition
|
|
Term
| What is trying to walk towards the plus ends, it pushes the microtubules to the poles? |
|
Definition
|
|
Term
| When this is disrupted chromosomes do not move to the poles properly? |
|
Definition
|
|
Term
| What causes the tubles to bend in the cell? |
|
Definition
|
|
Term
| Cells adhere to each other and the extracellular matrix through? |
|
Definition
| Cell Adhesion Molecules (CAMs) |
|
|
Term
| What are the two major classes of CAMs? |
|
Definition
| Homophilic and Heterophilic |
|
|
Term
| The intercellular domains of CAMs associate with different adapters, which can either link up to ____ ____or to ____ ____ |
|
Definition
| Actin cytoskeleton, intermediate filaments |
|
|
Term
| CAMs recruit ____ ____ ____ and control _____ _____ |
|
Definition
| cell signaling proteins, gene expression |
|
|
Term
| What are the types of cell junctions? |
|
Definition
| Anchoring, tight, and gap junctions |
|
|
Term
| What are the 3 kinds of anchoring junctions? |
|
Definition
| Adherens, desmosomes, hemidesmosomes |
|
|
Term
| Cadherin adhesion is what dependent? |
|
Definition
|
|
Term
| Cell-cell adhesions involve two types of interactions what are they? |
|
Definition
|
|
Term
| When the interactions occur laterally in one cell through the extracellular domains, the cytosolic domains, or both is called? |
|
Definition
|
|
Term
| When CAMs on one cell bind to the same or different CAMs in another cell this is called? |
|
Definition
|
|
Term
| What kind of interactions can induce more cis as well as trans interactions? This can lead to zippering and a Velcro like adhesion made of many weak bonds |
|
Definition
|
|
Term
| What terminal of the cadherin is the most important for specificity? |
|
Definition
|
|
Term
| What helps transmit shear force and provides strength and rigidity. They make attachments to intermediate filaments and use desmosomal cadherins as their CAMs. |
|
Definition
|
|
Term
| What are the two specialized cadherins of desmosomes? |
|
Definition
| desmoglein and desmocollin |
|
|
Term
| What seals off body cavities such as the intestinal lumen and the brain? |
|
Definition
|
|
Term
| What forms tight junctions? |
|
Definition
|
|
Term
| What differs from other tissues because it is mainly extracellular material (ECM)? |
|
Definition
|
|
Term
| Synthesis of ____ ____ begins inside the cell with the chemical modification of the newly made alpha chains and their assembly into triple-helical procollagen within the ER |
|
Definition
|
|
Term
| After secretion, ____ molecules are cleaved, associated laterally, and are covalently cross-linked into bundles called fibrils. |
|
Definition
|
|
Term
| ____ form larger assemblies called fibers |
|
Definition
|
|
Term
| What collagens make fibrils? |
|
Definition
|
|
Term
| What collagens make sheets? |
|
Definition
|
|
Term
| What collagens make cross-linked other collagens? |
|
Definition
|
|
Term
| Where are type I collagens found? |
|
Definition
|
|
Term
| Where are type II collagens found? |
|
Definition
|
|
Term
| ____ are abundant multiadhesive matrix proteins that are involved in cell migration and differentiation |
|
Definition
|
|
Term
| What do fibronectins contain? |
|
Definition
| binding sites for integrins, collagens, and proteoglycans |
|
|
Term
| Fibronectins are ____ from the cell and are important for ____ it to the matrix |
|
Definition
|
|
Term
| The ____ _____ ____ is foung in fibronectins and some other matrix proteins. It is recognized by several types of ____ |
|
Definition
| tripeptide sequence RGD, integrins |
|
|
Term
| ____ consist of membrane associated or secreted core proteins covalently linked to one or more glycosaminoglycan (GAG) chains. |
|
Definition
|
|
Term
| ____ is a highly hydrated GAG and a major compoenet of the ECM. It can bind to cell surface receptors and is involved in cell ____ and ____. |
|
Definition
| Hyaluronan, migration, proliferation |
|
|
Term
| Large proteoglycan aggregates conatin a central hyaluronan molecule that is noncovalently bound to the core protein of multiple other proteoglycans. These form a ____ gel. |
|
Definition
|
|
Term
| What are constructed of 12 copies of connexin proteins that assemble into a transmembrane channel that connects the cytoplasm of two adjacent cells? |
|
Definition
|
|
Term
| Small molecules and ions can pass through gap junctions, permitting ____ and ____ ___ of adjacent cells. |
|
Definition
| metabolic, electrical coupling |
|
|
Term
| The integration of cells into plant tissues is fundamentally different because of the? |
|
Definition
|
|
Term
| The plant cell wall is made of layers of ___ ____ embedded into a matrix of hemicellulose, pectin, extension, lignin, and other less abundant molecules. |
|
Definition
|
|
Term
| ____ is a large linear glucose polymer that is assembled outside the cell. |
|
Definition
|
|
Term
| ____ provides tracks that direct the polymerization of cellulose. |
|
Definition
|
|
Term
| ____ induced loosening of the cell wall permits elongation of the ell in a direction that is at a right angle to the orientation of the cellulose. |
|
Definition
|
|
Term
| Adjacent plant cells communicate and share materials through the _____. |
|
Definition
|
|
Term
| Plants do not have the ____ molecules found in animal cells |
|
Definition
|
|
