MCQOPTIONS
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MCQOPTIONS
This section includes 16 Mcqs, each offering curated multiple-choice questions to sharpen your Biochemistry knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
GPCR is comprised of ___________ |
| A. | 7 transmembrane helices |
| B. | 8 transmembrane helices |
| C. | 9 transmembrane helices |
| D. | 10 transmembrane helices |
| Answer» B. 8 transmembrane helices | |
| 2. |
Which second messenger signals the release of Ca+2 from endoplasmic reticulum? |
| A. | IP3 |
| B. | 1, 2 diacyl glycerol |
| C. | cAMP |
| D. | cGMP |
| Answer» B. 1, 2 diacyl glycerol | |
| 3. |
A hormone or ligand can be considered as ___________ |
| A. | First messenger |
| B. | Second messenger |
| C. | Third messenger |
| D. | Fourth messenger |
| Answer» B. Second messenger | |
| 4. |
The binding of ligands to many GPCRs leads to ___________ |
| A. | Decrease in concentration of certain intracellular signal molecules called second messengers |
| B. | Increase in concentration of certain intracellular signal molecules called second messengers |
| C. | Decrease in concentration of certain extracellular signal molecules called first messengers |
| D. | Increase in concentration of certain extracellular signal molecules called first messengers |
| Answer» B. Increase in concentration of certain intracellular signal molecules called second messengers | |
| 5. |
Which out of the following is not involved in signal transduction by β-adrenergic receptor pathway? |
| A. | GTP |
| B. | ATP |
| C. | cAMP |
| D. | cGMP |
| Answer» D. cGMP | |
| 6. |
Protein kinase A is ____________ |
| A. | Completely inhibited by cyclic AMP |
| B. | Allosterically activated by cyclic AMP |
| C. | Affected by cyclic AMP only under unusual circumstances |
| D. | Activated by covalent binding of cyclic AMP |
| Answer» C. Affected by cyclic AMP only under unusual circumstances | |
| 7. |
WHICH_SECOND_MESSENGER_SIGNALS_THE_RELEASE_OF_CA+2_FROM_ENDOPLASMIC_RETICULUM??$ |
| A. | IP3 |
| B. | 1,2 diacyl glycerol |
| C. | cAMP |
| D. | cGMP |
| Answer» B. 1,2 diacyl glycerol | |
| 8. |
GPCR_is_comprised_of |
| A. | 7 transmembrane helices |
| B. | 8 transmembrane helices |
| C. | 9 transmembrane helices |
| D. | 10 transmembrane helices |
| Answer» B. 8 transmembrane helices | |
| 9. |
Which of the following serves as a neurotransmitter in adrenergic neurons? |
| A. | Serotonin |
| B. | Epinephrine |
| C. | Dopamine |
| D. | Histamine |
| Answer» C. Dopamine | |
| 10. |
A hormone or ligand can be considered as |
| A. | First messenger |
| B. | Second messenger |
| C. | Third messenger |
| D. | Fourth messenger |
| Answer» B. Second messenger | |
| 11. |
The binding of ligands to many GPCRs leads to |
| A. | Decrease in concentration of certain intracellular signal molecules called second messengers |
| B. | Increase in concentration of certain intracellular signal molecules called second messengers |
| C. | Decrease in concentration of certain extracellular signal molecules called first messengers |
| D. | Increase in concentration of certain extracellular signal molecules called first messengers |
| Answer» B. Increase in concentration of certain intracellular signal molecules called second messengers | |
| 12. |
Which of the following catalyzes the cutting of PIP2 into 2 moles of IP3 and diacylglycerol in cell signaling? |
| A. | Phosphokinase C |
| B. | Phospholipase C |
| C. | Lipokinase |
| D. | Phosphodiesterase C |
| Answer» C. Lipokinase | |
| 13. |
Which out of the following is not involved in signal transduction by β-adrenergic receptor pathway?$ |
| A. | GTP |
| B. | ATP |
| C. | cAMP |
| D. | cGMP |
| Answer» D. cGMP | |
| 14. |
Protein kinase A is |
| A. | Completely inhibited by cyclic AMP |
| B. | Allosterically activated by cyclic AMP |
| C. | Affected by cyclic AMP only under unusual circumstances |
| D. | Activated by covalent binding of cyclic AMP |
| Answer» C. Affected by cyclic AMP only under unusual circumstances | |
| 15. |
Which of the following is not a G-protein coupled receptor? |
| A. | Glycine receptor |
| B. | Adrenergic receptor |
| C. | Glutamate receptor |
| D. | Muscarinic receptor |
| Answer» B. Adrenergic receptor | |
| 16. |
Which out of the following statements is true about G-protein couple receptors? |
| A. | The N-terminal chain is extracellular and C-terminal chain is intracellular |
| B. | It contains 5 trans-membrane hydrophobic sections |
| C. | There are more extracellular loops than intracellular loops |
| D. | The binding region for G-protein involves 2 extracellular loops |
| Answer» B. It contains 5 trans-membrane hydrophobic sections | |