AIPGE 09 MDS Biochemistry

Biochemistry

18. True about denaturation of proteins are all except:
a) Unfolding occurs
b) Disruption of secondary structure occurs
c) Sequence of amino acids remain the same
d) Biological activity is retained
Ans: d) Biological activity is retained ooooooooo

19. Insulin causes lipogenesis by all except:
a) Increasing acetyl-CoA carboxylase activity
b) Increases the trAnsport of glucose into the cells
c) Inhibits pyruvate dehydrogenase
d) Decreases intracellular cAMP level
Ans: c) Inhibits pyruvate dehydrogenase

20. True about G protein coupled receptors is:
a) G proteins bind to hormones on the cell surface
b) All the three subunits alpha, beta and gamma should bind each other G protein to act
c) G proteins act as inhibitory and excitatory because of difference in alpha subunit
d) G protein is bound to GTP in resting state
Ans: c) G proteins act as inhibitory and excitatory because of difference in alpha subunit ooooooo

21. Thiamine deficiency causes decreased energy production because
a) It is required for the process of transamination
b) It is co-factor in oxidative reduction
c) It is co-enzyme for transketolase in pentose phosphate pathway
d) It is co-enzyme for pyruvate dehydrogenase
Ans: d) It is co-enzyme for pyruvate dehydrogenase

22. All are true about glutathione except:
a) It is a tripeptide
b) It converts hemoglobin to methemoglobin
c) It conjugates xenobiotics
d) It scavenges free radicals and superoxide ions
Ans: b) It converts hemoglobin to methemoglobin oooooo

23. In molecular cloning, Blue-white screening is used for:
a) To screen for recombinant vectors
b) To detect gene mutations
c) To identify desired chromosomal DNA insert in plasmid vectors
d) To detect host DNA in situ
Ans: c) To identify desired chromosomal DNA insert in plasmid vectors

24. Steroid hormone receptors have attachment site for all except:
a) Steroid hormone
b) Transcription repressors
c) Hormone responsive element
d) Transcription activators
Ans: b) Transcription repressors

25. Why fetal cells continue to divide but terminally differentiated adult do not divide
a) There are many cyclin inhibitors which prevent cell to enter into S phase in adult
b) Phosphatase absent in fetal cells
c) Proteinase is absent in fetus
d) Absence of CD kinase
Ans:

26. All are true about glutathione except:
a) It is a tripeptide
b) It converts hemoglobin to methemoglobin
c) It conjugates xenobiotics
d) It scavenges free radicals and superoxide ions
Ans: It converts methhemoglobin to hemoglobin