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TLS Online TPP Program

#Question id: 23849

Which pathway regulates the contraction of vertebrate smooth muscle? 

#Unit 2. Cellular Organization
  1. When the Ca2+ level rises → Ca2+ binds CaM→ MLC kinase becomes inactive → dephosphorylates the myosin LC → unfolds the myosin II→ assemble into bipolar filaments for contraction. 
  2. When the Ca2+ level rises→Ca2+ binds CaM→activates MLC kinase→ phosphorylates the myosin LC→unfolds the myosin II → assemble into bipolar filaments for contraction. 
  3. When the Ca2+  returns to its resting level → Ca2+ binds CaM → activates MLC kinase→ phosphorylates the myosin LC → unfolds the myosin II→ causing muscle contraction.
  4. When the Ca2+ level rises→ Ca2+ binds CaM→ activates MLC kinase → phosphorylates the myosin LC → myosin adopts a folded conformation→ assemble into bipolar filaments for contraction. 
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TLS Online TPP Program

#Question id: 294

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following pairs of amino acids would you predict to only participate in Van der Waals interactions in the three dimensional folding of a protein:
TLS Online TPP Program

#Question id: 88

#Unit 1. Molecules and their Interaction Relevant to Biology

Anomers can be interconverted ________.
TLS Online TPP Program

#Question id: 1232

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following mutations might confer a competitive advantage to an athlete by raising his or her hematocrit?

a. excess production of erythropoietin                       

b. decreased production of erythropoietin

c. EpoR that cannot bind STAT5                  

d. EpoR that cannot bind SHP1

e. EpoR that cannot bind JAK2
TLS Online TPP Program

#Question id: 27070

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following statements is correct regarding the stereochemistry of Thr, Ile 
1. Thr, Ile is special case because of two chiral center exist in L-Ile in 2R,3S and L-Thr in 2R,3S configuration 
2. Thr, Ile is special case because of two chiral center exist in D-Ile in 2R,3S and D-Thr in 2R,3S configuration 
3. Thr, Ile is special case because of two chiral center exist in L–Ile in 2S,3R and L–Thr in 2S,3R 
4. Thr, Ile is special case because of two chiral center exist in D–Ile in 2S,3R and D–Thr in 2S,3R
TLS Online TPP Program

#Question id: 27069

#Unit 1. Molecules and their Interaction Relevant to Biology

Choose the correct option regarding the stereochemistry of given compound 
TLS Online TPP Program

#Question id: 27068

#Unit 1. Molecules and their Interaction Relevant to Biology

Isoleucine and Threonine have two chiral carbons so exists in multiple RS configuration, choose the correct option regarding the given fig.
1. a is D-threonine is (2S, 3S) threonine
2. b is L-threonine is (2R,3S) threonine
3. a is L-threonine is (2S, 3R) threonine
4. b is D-threonine is (2R,3S) threonine