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TLS Online TPP Program

#Question id: 8845

The experimental approach taken in current biological investigations presumes that

#Unit 9. Diversity of Life Forms
  1. simple organic compounds can be synthesized in the laboratory from inorganic precursors, but complex organic compounds like carbohydrates and proteins can only be synthesized by living organisms.
  2. living organisms can be understood in terms of the same physical and chemical laws that can be used to explain all natural phenomena.
  3. although a life force, or vitalism, exists in living organisms, this life force cannot be studied by physical or chemical methods.
  4. living organisms are composed of the same elements present in nonliving things, plus a few special trace elements found only in living organisms or their products. 
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TLS Online TPP Program

#Question id: 13163

#Unit 4. Cell Communication and Cell Signaling

Following statements are regarding to the interaction between β2-adrenergic receptor and G- protein.
TLS Online TPP Program

#Question id: 13162

#Unit 4. Cell Communication and Cell Signaling

In the amoeba Dictyostelium discoideum, cAMP acts as an extracellular signalling molecule and binds to and signals via a G protein–coupled receptor; it is not a second messenger. Amoeba cells were transfected with genes encoding two fusion proteins: a Gα fused to cyan fluorescent protein (CFP), and a Gβ fused to yellow fluorescent protein (YFP). CFP normally fluoresces 490-nm light; YFP, 527-nm light. In which conditions fluorescence
energy transfer occur from CFP to YFP?
TLS Online TPP Program

#Question id: 13161

#Unit 4. Cell Communication and Cell Signaling

Which of the following mechanism depends on the activation of heterotrimeric G proteins?
TLS Online TPP Program

#Question id: 13160

#Unit 4. Cell Communication and Cell Signaling

According to the Switching mechanism, monomeric G proteins exist in two states. Match the following states (Column I) with correct mechanism (Column II).

Column I

Column II

A. “ON” state 

i. switch I and switch II, are bound to the terminal γ phosphate of GTP through interactions with the backbone amide groups of conserved threonine and glycine residues.

B. “OFF” state

ii. GTPase-activating proteins

 

iii. guanine nucleotide exchange factor

 

iv. Due to the removal of the γ phosphate by GTPase-catalyzed hydrolysis causes switch I and switch II to relax into a different conformation

TLS Online TPP Program

#Question id: 13159

#Unit 4. Cell Communication and Cell Signaling

How signaling is involved in ensuring that yeast cells fuse only with cells of the opposite mating type?
TLS Online TPP Program

#Question id: 1262

#Unit 4. Cell Communication and Cell Signaling

Although MAP kinase is often activated in multicellular animals by RTKs or cytokine receptors, signaling from other receptors can activate MAP kinase in other eukaryotic cells. we consider the mating pathway in the yeast S. cerevisiae, a well-studied example of a MAP kinase cascade linked to G protein–coupled receptors (GPCRs). Which of the following statement is incorrect?