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.

TLS Online TPP Program

#Question id: 23155

#Unit 13. Methods in Biology

Match the following ions in column I with their relevant dyes column II.

Column I                                                       Column II

1. K+                                                                 a. Fura-2

2. Ca2+                                                             b. SNARF-1

3. H+                                                                 c. Ion potassium green

Which of the following options is correct?

TLS Online TPP Program

#Question id: 23152

#Unit 13. Methods in Biology

A fluorescent dye SNARF-1 that is sensitive to H+ concentrations can be used to monitor the cytosolic pH of 

1. Alkaline cells

2. Acidic cells 

3. Dead cells

4. Live cells

Which of the following options are incorrect?

TLS Online TPP Program

#Question id: 23151

#Unit 13. Methods in Biology

If the concentration of Ca2+ is high inside the cell and fura-2 dye is used to map the concentration which of the following conditions will prevail?

1. Fluorescence will decrease

2.  Fluorescence will increase

3. Emission of light at higher wavelength

4. Emission of light at lower wavelength

Which of the following options are correct?

TLS Online TPP Program

#Question id: 23148

#Unit 13. Methods in Biology

There are two proteins A and B to be visualized under fluorescence microscopy. Both of them are excited with same wavelength of light but A emits longer wavelength. Hence we can conclude that 

1. A is denser molecule than B

2. B is denser molecule than A

3. A is lighter molecule than B

4. B is lighter molecule than A

Which of the following option is incorrect?

TLS Online TPP Program

#Question id: 23141

#Unit 13. Methods in Biology

Resolution of a light microscope is 0.42nm at 300 wavelength of light. If the specimen is viewed under oil what is the refractive index?

TLS Online TPP Program

#Question id: 19467

#Unit 13. Methods in Biology

Eosin is an acidic dye which basically binds to which molecules?

1. DNA

2. Carbohydrate

3. Glutamic acid

4. Aspartic acid

5. Asparagine

Which combination of the above options are correct?