Which of the following is a mechanism for down regulation of signaling from G protein-coupled receptors?

a. a change in the Kd of the receptor-hormone complex

b. proteolysis of the Gα subunit                     

c. hydrolysis of cAMP to 5´-AMP

d. dephosphorylation of adenylyl cyclase

TLS Online TPP Program

#Question id: 21257

#Unit 12. Applied Biology

Lysine is a member of the_______________of amino acids.

TLS Online TPP Program

#Question id: 21258

#Unit 12. Applied Biology

Some classes of mutants were obtained from the parental strain as the source of genetic material for transduction:

I) A strain that are resistance to thialysine

II) A strain in which both the threonine-regulated AK and HD were resistant to feedback inhibition by threonine

III) A strain is selected for ß-hydroxynorvaline Sensitive, in which HDI was sensitive to both inhibition and repression and the threonine-regulated AK was constitutively synthesized 

TLS Online TPP Program

#Question id: 21259

#Unit 12. Applied Biology

Production of l-Threonine amino acid used for feeding pigs and poultry, Starting from l-aspartate, the pathway involves five steps catalyzed by five enzymes sequence of using enzyme is that;

TLS Online TPP Program

#Question id: 21260

#Unit 12. Applied Biology

L-Cysteine has traditionally been obtained by extracting it from acid hydrolysates of human hair and animal feathers. High levels cannot be synthesized from glucose because l-cysteine feedback inhibits the enzyme, which catalyzes one of the steps in the biosynthesis of l-cysteine. These enzyme are,

TLS Online TPP Program

#Question id: 21261

#Unit 12. Applied Biology

A copy of the gene encoding enzyme, which is the rate-limiting enzyme in the normal tryptophan biosynthetic pathway is,

TLS Online TPP Program

#Question id: 21262

#Unit 12. Applied Biology

A constitutive promoter derived from the cauliflower mosaic virus is__