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Flashcards in Molecular Bio Deck (114)
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31

What is the role of BH3-only protein in apoptosis?

apoptotic stimulus

32

LAPs block caspases. true or false?

true

33

Anti-IAPs neutralize the IAPs and liberate what?

the caspases; leads to apoptosis

34

In regards to cancer genes, ___ involves single mutation event and activation of gene causing proliferation (dominant)

oncogenes

35

Describe tumor supressor genes and how they affect cancer

loss of function mutation. recessive - both alleles must be mutated

36

Heriditary form of Rb

loss of function or deletion of ONE copy of Rb in every cell- because defect is inherited

37

Sporadic form of Rb

since there are two normal alleles to begin with, need two sporadic mutations to occur

38

Describe the Apc mutation and how it can cause cancer

loss of function - Apc is a tumor suppressor gene

39

Gated Ion channels are common in ___ tissue

nervous

40

GPCRs use ___ transmembrane proteins

7-pass

41

Receptor tyrosine kinases are enzyme coupled. true or false?

true

42

Describe how a receptor tyrosine kinase receptor works

1.RTK binds to SH2 of Grb2
2.Grb2 also has SH3 domain
3.SH3 of Grb2 binds to pralines of SOS which then binds to Ras
4.Ras binds Raf and then rapid activation

43

___ subunits are compact and globular and are flexible structures 5-9 nm in diameter

actin

44

In treadmilling, the plus end remains in __ formation and the minus end adopts ___ formation

T;D

45

Nucleotide hydrolysis leads to ____

treadmilling

46

Treadmilling predominates in ___ filaments

actin

47

The following characteristics describe what:
long hollow cylinder; are made of tubulin, outer diameter 25nm, have one end attached to centrosome

microtubule

48

If nucleotide hydrolysis proceeds more rapidly than subunit addition, the cap is lost and the microtubule begins to shrink. This is called what?

catastrophe

49

GTP-containing subunits may still add to the shrinking end, and if enough add to form a cap, then microtubule growth resumes. This is called what?

rescue

50

dynamic instability predominates in ____

microtubules

51

the following characteristics describe what:
rope-like fiber; 10 nm diameter; help with mechanical strength

intermediate filaments

52

Describe the construction of intermediate filaments

alpha helical in monomer; coiled-coil dimer; staggered tetramer of two coil-coiled dimers

53

True or false? in intermediate filaments, there is no nucleotide binding site and structural polarity

true

54

Keratins impart mechanical strength by anchoring intermediate filaments at site of cell-cell contacts called ____ and cell-matrix contacts called _____

desmosomes; hemidesmosomes

55

In regards to accessory proteins for actin filaments, what does the ARP complex do?

nucleates assembly to form a web and remains associated with minus end

56

In regards to accessory proteins for actin filaments, what does cofilin do?

binds ADP-actin filaments, accelerates disassembly

57

In regardss to accessory proteins for microtubules, what does gamma-TuRC do?

nucleates assembly and remains associated with the minus end

58

Rac/Cdc42 = ___ actin
Rho = ___ actin

dynamic; rigid

59

Rac activation promotes polymerization at the cell periphery leading to the formation of ___ extensions

lamellipodia

60

Cdc42 activation triggers actin polymerization and bundling to form ____

filopodia