MCM_Final_TBL7 Flashcards

Question

The nucleus contains

Answer 1

1. nuclear **envelope** (membrane) * entry in/out regulated by *nuclear* *pores* 2. **nucleolus** is the dark area where * **FUNCTIONAL RNAs** (ribsome, tRNA, small RNAs) are _transcribed and assembled_ 3. **heterochromatin** (DNA site)

Answer 2

* envelope allows _mRNA out_ *ONLY WHEN* they are ready (i.e mature mRNA) or _proteins in_ that have the *correct ID* * **nuclear pore complexes** regulate traffic in or out * the _OUTER_ envelope IS THE **Rough ER** * **chromatin** (DNA) is BOUND to the INNER membrane

Answer 3

* used in **karyotyping** * it is an **INHIBITOR** that arrests the cell in **METAPHASE** so that the _chromosome pairs_ can be easily _vizualized_

Answer 4

* used to ***vizualize*** _LARGE chromosome changes_ (LCC). * 0.5% of all live births have LCC * 50% of first trimester **miscarriages** have LCC * 95% of **tumor** cells have LCC * **FISH Technique** * **changes** in **_length**_ & _**gene location_** can be detected with FISH * _stains_ the chromosome w/ antibodies to determine what part of _gene is mising_

Answer 5

* large **helix** of DNA complised of _two strands and base pairs_ * wound by **histones** to f_orm *nucleosomes*_ * nucleosomes FOLD into _chromatin_

Answer 6

* signalling that involves **altering ATP usuage** and allocations in a specific way (fear --\> ATP usuage via epinerphrine signaling) Needs: A) **Specific** for a given **situation** B) **Amplifies** (triggers more **ATP use**) C) **Integrates** (can turn on/off) D) **Timely** (local and shuts off)

Answer 7

* cell targets itself * signal molecule is created by the same cell who will use it * ex) immune cells

Answer 8

* bewteen two cells *connected* by a gap junction * ex) two neurons communicate via neurotransmitters

Answer 9

* a cell targets a nearby cell * **"local signaling"** * helps *synchronize tissue functions* * ex) hormones (Growth Factor Hormone), histamine

Answer 10

* a cell targets a DISTANT cell through the BLOODSTREAM * ex) horomes (Epinephrine)

Answer 11

1. **Resting** state 1. *primary ligand binds* and starts the patway 2. **Activation** of a *key enzyme* that generates a SECONDARY *_MESSAGE_ (uses **ATP**)* 3. a **SECONDARY** ***_MESSENGER_*** activates the *target protein* 4. 1 target protein will stop the cascade locally ex) 1 epinephrine signal will use 100,000 glucoses

Answer 12

* _**total** **OFF**_ state * GCPR is **phosphorylated** * **GDP** is **bound** to *Trimeric G-Protein* subunits (alpha, beta, gamma)

Answer 13

* signal will induce changes: 1. *phosphate* **OFF** the GPCR 2. the **ligand** can now **bind** 3. *G-Protein* and *GPCR* **attach** to each other 4. **GTP** is **exchanged**

Answer 14

* **alpha** subunit (of the trimeric protein) **disocciates** * triggers a *structure **change***

Answer 15

big picture: adenyl cyclase (AC) ---\> cAMP ---\> PKA ---\> target protein 1. G⍺-s **bind with adenyl cyclase** * AC is active and **makes cAMP** * energy consumption is increased 1 adenyl cyclase makes many cAMP

Answer 16

* cAMP frees Protein Kinase A * seperates catalytic domain from regulatory domains cAMP acivates many PKA

Answer 17

* target **proteins are phosphorylated** and activity of them change * each tissue has different target proteins with _different biological responses_ Protein Kinase A uses many ATP to make a huge biological response

Answer 18

* **stimulates** adenyl **cyclase** 1. **Glucagon** (**prevent** **low** blood **glucose** by *converting* liver stored _glycogen to glucose_) 2. **Epinephrine** to *regulate* metabolic enzymes

Answer 19

big picture (ex is Acetylcholine) : A) PhosphoLipase Cβ + PIP 2 ---\> IP3 Bi) IP3 ---\> Protein Kinase C --\> target protein Bii) IP3 ---\> Ca2+ release ---\> calmoduline kinase activation **αq** _binds_ and _activates_ Phospholipase C-Beta (**PLC β)**, which _cleaves_ PhosphatIdylinositol bisPhosphate (**PIP2**) _into_ diacylglycerol and Inositol triPhosphate (**IP3**), and _mediates_ the _activation_ of **Proetin Kinase C and Calmoduline Kinase II**.

Answer 20

* **inhibits** adenyl **cylase** 1. **serotonin (**relaxes you) 2. **cannabis (**relaxes you**)**

Answer 21

* **activates** PL**Cβ** 1. **epinephrine** (_fear_) 2. **acetylcholine**

Answer 22

* on/off pair * paired action is called **signal integration**

Answer 23

* *vibrio cholerae =* **cholera toxin** or **toxin**-coregulated **pilus** * symptoms: * voluminous rice water **diarrhea** * caused by c_ontaminated drinking water_ * **gram-negative** ***bacteria (***peptidoglycan sanwhich between membranes, so hard to see i.e negative) _use flagella_ to **bypass** the **mucosal** lining of the **intestines**

Answer 24

* *Bordetella pertussis =* **pertussis toxin/ adenylate cyclase toxin** * _activates_ AC by **INHIBITING G⍺i** * symptoms: * **coughing** and progressive whooping symptoms * **eliminated** by **DTaP** vaccination

Answer 25

1. **phosphodiesterase** DEGRADES _cAMP ---\> AMP_ or _GTP ---\> GDP_ * therefore, you will see AMP in metabolic pathway when SIGNAL IS OFF 2. **phosphorylation** one of the target proteins is an enzyme that forces GPCR into a totally inactive state 3. **β-arrestin** will _bind to GPCR_ and *prevent* the G-protein complex from forming (**desensitization**) * causes _endocytosis of GPCR_ through **clathrin,** which will retrograde GPCR back to the lysosome for recyling

Answer 26

* mesh of **filamentous** elemens called: 1. microtubles 2. microfilaments 3. intermediate filaments (actin) * function: * **structural** stability for cell shape * important for cell **movement and rearrangement** of cytoplasmic components

Answer 27

* **thickest**; vary in length with **hollow lumen** * **dense** wall made of **tubulin heterodimers (⍺-t**ubulin & **β-t**ubulin) * tubulin heterodimers _arrange in chains_ called **profilaments** that align _parralel_ to make walls * **13 profilaments** = one microtubule

Answer 28

* exist in a state of **dynamic instability** (undergoing abrupt changes in legth through *polymerization* and *depolymerization*) * each microtubule is **_polarized_** with: * **+ end**: site of growth/**polymerization** * **- end**: site of shrinkage/**depolymerization**

Answer 29

1. **GTP-loaded tubulin subunits** *_initiate_* _polymerization_ 2. GTP **hydrolysis** changes the profiliment from tublin-_GTP structure to tubulin-GDP sturcture_ * growing microtubulines maintain a **cap** of tubulin-GTP _to keep straight_ * shrinking end characterized by fountain-like arrays 3. cycle _complete by exchange GDP from the shrinking_ products with GTP

Answer 30

* transition from _growth to shrinkage_ in microtubule

Answer 31

* transition from _shortenting to growth_ in microtubule

Answer 32

* **initation (origin)** of the microtubule "microtubule nucleation" * contains **gamma-tubulin** * the starting point for assembly

Answer 33

1. maintenance of **cell shap**e and **structure** 2. **transportation** of vesicles and organelles in cytoplasm 3. organization of **cilia** and **flagella** 4. formation of the **mitotic spindle** during cell division 1. **Taxol (Paclitaxel)** will _**permanently stabilize** microtubles_ and lead to *cell death* (useful for **cancer treatment** and hindering rapid cell growth in G1 phase)

Answer 34

* thinnest and flexible * consists of _**two** intertwing (**helical**) strands_ of **globular** proteins * **F-actin** = intact microfilaments * **G-actin** = unpolymerized/unassembled protein subunits * **powered by ATP hydrolysis** to form * hydrolysis of _ATP --\> ADP_ = destabilation/_depolymerization_ of the microfilament * **most abundant protein** in mammal cells

Answer 35

* **dynamic** movement in **microfillaments** * in **actin** filaments, _one end grows while the other end shrinks_ resulting in the filament seemingly "moving" across the cytosol

Answer 36

* promotes treadmilling in actin * promotes the _elongation of pre-existing_ actin filaments

Answer 37

* actin binding protein * involved in the **assembly** of the actin cytoskeleton

Answer 38

* actin binding protein * involved in the **disassembly/shrinking** of the actin cytoskeletona

Answer 39

* actin binding protein * involved in **branching** of the actin cytoskeleton

Answer 40

* cell **organization** * establish **cell polarity** * core of actin filaments provides **microvilli** in intestins

Answer 41

**actin** plays an important role in **cell divison**: causes the _cell to stop moving_ and _orients/guides_ the microtubles of the *_mitotic spindles_* * the contracile ring = actin microfilament * seperates the daughter cells during *cytokinesis*

Answer 42

* microfillament * **maintains** the **structure** of _epitelial cell_ by a **belt** of _actin_ fillaments * _links_ the cytoskeleton of _adjacent cells_

Answer 43

* uses **_actin_** filament _rigidity_ to **sense vibration** * found on the surface of the **inner ear**

Answer 44

* **actin** serves as a track for a MOTOR protein called **myosin** * sliding of actin & mysosin = **muscle contractions**

Answer 45

* cells need to **move** in *repsonse to **stimuli*** * migration of white BC toward wound sites to fight infection * movement is assisted by **actin filaments** of the cytoskeleton of the cells

Answer 46

* **depolymerizes actin** filaments and *prevents cell crawling movement*

Answer 47

* **stabilizes actin PERMANANTLY** and *prevents cell crawling movement*

Answer 48

* **rope** like * **toughest** and ***most durable*** * *CRITICAL* for maintaining **_cell shape and structure_** * abundant in cells that are subjected to **mechanical stress often** (*skin, connective tissue, and muscle cells*) * though _microtubules/fillaments_ help, they _break easily_

Answer 49

* *two* COILED strands form **dimer** * _dimer_ will _stack_ to form **tetrameter** * **8 tetrameters = 1 filament**

Answer 50

* **keratin**: forms the tissues of the **hair, skin, nails** * **protects** outside of the skin **against abraisions** and sticks cells together

Answer 51

1. **Vimetin** * found in FIBROBLASTS (make XtraCell Matrix + collagen), ENDOTHETIAL cells, and LEUKOCYTES (White BC) 2. **Desmin** * found in MUSCLE cells 3. **Glial Fibrillary Acidic Factor** (**GFAP**) 1. found in ASTROCYTES ( a type of glial/glue cells that help neurons in the CNS/BRAIN)

Answer 52

* **neurofillaments**: subunirs of the _major_ intermediate _filaments_ of _neurons_

Answer 53

* **Lamins**: forms **NUCLEAR lamina** inside the nuclear **_envelope_** * provides **structural support** for the nucleus * assists with **CHROMATIN organization**

Answer 54

* TYPE III intermediate filament * can be used for the **IDENTIFICATION of *brain tumor***

Answer 55

* use **ATP hydrolysis** to ***move* cell cargo** (proteins, organelles, etc) _along_ the **_cytoskeletal filaments_** * _**attach**_ to *cargo* with one end & to *microtubules/actin* with the other end Main Types are: 1. **Dynein** 2. **Kinesin** 3. **Myosin**

Answer 56

* **movement** of *_cell cargo_* **to and from a neuron cell body through the axoplasm** (cytoplasm of its axon) * driven by **molecular** **motors** that run on **microtubule** track * neurons: specialized nerve cells that transmit nerve impulses

Answer 57

* **Kinesin = (+) end** of microtubule **= Anterograde** * **Dyenein = (-) end** of microtube **= Retrograde**

MCM_Final_TBL7 Flashcards

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