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: 10304

#Unit 6. System Physiology – Plant

Pyruvate is coverted into the Acetyl-CoA, Acetyl-CoA contain the acetyl group which are comes from the pyruvate and Coenzyme A (CoA) that contain other groups such as;

a) A reactive thiol (—SH) group that is critical to the role of CoA as an acyl carrier in a number of metabolic reactions

b) contain pantothenic acid,  A hydroxyl group of pantothenic acid is joined to a modified ADP moiety by a phosphate ester bond

c) pantothenic acid carboxyl group is attached to β-mercaptoethylamine in amide linkage

d) Hydroxyl group at the 3’ position of the ADP moiety has a phosphoryl group not present in free ADP

which of the following correct observation about Coenzyme A (CoA)?

#Question id: 10303

#Unit 6. System Physiology – Plant

During glycolysis, if radiolabelled the glucose at 3 or 4 carbon then what will be the correct prediction about radiolabelling in the cycle?

#Question id: 10300

#Unit 6. System Physiology – Plant

which of the following lipid occur in cells only in the inner mitochondrial membrane is about 15% composition only ;

#Question id: 10298

#Unit 6. System Physiology – Plant

Wernicke-Korsakoff syndrome is more common among people with alcoholism than in the general population, The syndrome can be exacerbated by a mutation in the gene for;

#Question id: 10297

#Unit 6. System Physiology – Plant

The following statements are related to pentose phosphate pathway.

a) The first and third steps are oxidations with large, negative standard free-energy changes and are essentially irreversible in the cell

b) NADPH rises and inhibits the first enzyme in the pentose phosphate pathway. As a result, more glucose 6-phosphate is available for glycolysis

c) All the enzymes of the reversible reaction of the pentose phosphate pathway are located in the cytosol

d) The NADPH is used for biosynthetic reactions such as lipid synthesis and nitrogen assimilation in the cytosol

which one of the following combination  of above statements is incorrect?

#Question id: 10295

#Unit 6. System Physiology – Plant

Reactions of the pentose phosphate pathway regeneration run six turns of this cycle, what will be predict after that?