Which of the following statements is (are) true of actin assembly?

a. ADP-actin can assemble into filaments.    

b. Actin (+) ends grow faster than actin (-) ends.

c. ATP-actin can assemble into filaments.

d. Toxins that alter the assembly of actin filaments have been used as tools to study actin in living cells.

TLS Online TPP Program

#Question id: 24486

#Unit 3. Fundamental Processes

Splicing is an …………reaction that proceeds through a pentavalent phosphorous intermediate.

TLS Online TPP Program

#Question id: 28696

#Unit 2. Cellular Organization

N-linked oligosaccharide is attaching carbohydrate chain to the amide nitrogen of which amino acid residue?

TLS Online TPP Program

#Question id: 2122

#Unit 2. Cellular Organization

The inner (plasma) membrane of E. coli is about 75% lipid and 25% protein by weight.  How many molecules of membrane lipid are there for each molecule of protein?  (Assume that the average protein is Mr 50,000 and the average lipid is 750.)

TLS Online TPP Program

#Question id: 2301

#Unit 2. Cellular Organization

Microtubules are involved in the.

TLS Online TPP Program

#Question id: 2864

#Unit 2. Cellular Organization

In E. coli, the five contiguoustrp genes encode enzymes that sythesize the amino acid tryptophan. These genes are expressed efficiently only when tryptophan is limiting. The genes are controlled by a repressor, just as the lac genes are, although in this case, it is the absence of its ligand (tryptophan) that relieves repression, match trp genes to their gene product,

Trp genes	Gene products
trpE	anthranilate synthetase
trpD	phosphoribosyl anthranilate transferase
trpC	phosphoribosyl anthranilate isomerase-indole glycerol phosphate synthetase
trpB	tryptophan synthetase beta
trpA	tryptophan synthetase alpha