Flashcards in Molecular Bio Deck (114)
What is the role of BH3-only protein in apoptosis?
LAPs block caspases. true or false?
Anti-IAPs neutralize the IAPs and liberate what?
the caspases; leads to apoptosis
In regards to cancer genes, ___ involves single mutation event and activation of gene causing proliferation (dominant)
Describe tumor supressor genes and how they affect cancer
loss of function mutation. recessive - both alleles must be mutated
Heriditary form of Rb
loss of function or deletion of ONE copy of Rb in every cell- because defect is inherited
Sporadic form of Rb
since there are two normal alleles to begin with, need two sporadic mutations to occur
Describe the Apc mutation and how it can cause cancer
loss of function - Apc is a tumor suppressor gene
Gated Ion channels are common in ___ tissue
GPCRs use ___ transmembrane proteins
Receptor tyrosine kinases are enzyme coupled. true or false?
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
___ subunits are compact and globular and are flexible structures 5-9 nm in diameter
In treadmilling, the plus end remains in __ formation and the minus end adopts ___ formation
Nucleotide hydrolysis leads to ____
Treadmilling predominates in ___ filaments
The following characteristics describe what:
long hollow cylinder; are made of tubulin, outer diameter 25nm, have one end attached to centrosome
If nucleotide hydrolysis proceeds more rapidly than subunit addition, the cap is lost and the microtubule begins to shrink. This is called what?
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?
dynamic instability predominates in ____
the following characteristics describe what:
rope-like fiber; 10 nm diameter; help with mechanical strength
Describe the construction of intermediate filaments
alpha helical in monomer; coiled-coil dimer; staggered tetramer of two coil-coiled dimers
True or false? in intermediate filaments, there is no nucleotide binding site and structural polarity
Keratins impart mechanical strength by anchoring intermediate filaments at site of cell-cell contacts called ____ and cell-matrix contacts called _____
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
In regards to accessory proteins for actin filaments, what does cofilin do?
binds ADP-actin filaments, accelerates disassembly
In regardss to accessory proteins for microtubules, what does gamma-TuRC do?
nucleates assembly and remains associated with the minus end
Rac/Cdc42 = ___ actin
Rho = ___ actin
Rac activation promotes polymerization at the cell periphery leading to the formation of ___ extensions