This member of the AKAP family, designated mAKAP, anchors both PDE and the regulatory subunit  of PKA to the nuclear membrane, maintaining them in a negative feedback loop that provides close local control of the ATP level and PKA activity.

B- The basal level of PDE activity in the presence of hormone (resting state) keeps cAMP levels below those necessary for PKA activation. 

C- Activation of β-adrenergic receptors causes an increase in cAMP to a level in excess of that which can be degraded by PDE. 

D- The resulting binding of cAMP to the R subunits of PKA releases the active catalytic (C) subunits into the cytosol. Some C subunits enter the nucleus, where they phosphorylate and thus activate certain transcription factors . Other C subunits phosphorylate PDE, stimulating its catalytic activity.

E-  Active PDE hydrolyzes cAMP, thereby driving cAMP levels back to basal levels and causing re-formation of the inactive PKA C-R complex. Subsequent de-phosphorylation of PDE returns the complex to the resting state.

#Question id: 742

#Unit 1. Molecules and their Interaction Relevant to Biology

Match the following

#Question id: 741

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of following statements are INCORRECT about secondary structure of proteins

A. Long block of Glu residues segment of the chain will not form an alpha helix at pH 7.0 but it ll take helical confirmation below its pKR value

B. Long block of Lys residues segment of the chain will not form an alpha helix at pH 7.0 but it ll take helical confirmation above its pKR value

C. Long block of Ala residues segment of the chain will not form an alpha helix at pH 7.0 but it ll take helical confirmation below its pKR value

D. Histidine side chain remain uncharged over pH range 3-6

#Question id: 740

#Unit 1. Molecules and their Interaction Relevant to Biology

The conformation of the backbone of a polypeptide is described completely by the angle(s) of rotation about which bond(s)?

#Question id: 739

#Unit 1. Molecules and their Interaction Relevant to Biology

What is true about the rotation about bonds in a protein backbone?

#Question id: 738

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following is correct for peptide bonds

A) C and N are shorter than typical C-N bonds.

B) C and N are longer than typical C-N bonds.

C) C and O are longer than typical C=O bonds.

D) C and O are shorter than typical C=O bonds.

#Question id: 737

#Unit 1. Molecules and their Interaction Relevant to Biology

Which structure below indicates the proper hydrogen-bonding pattern between amino acids in an α-helix? (Dashed lines represent the hydrogen bonds.)