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TLS Online TPP Program

#Question id: 10308

Oxidative decarboxylation of pyruvate to acetyl-CoA by the PDH complex, how the pyruvate dehydrogenase complex carries out the five consecutive reactions in the decarboxylation and dehydrogenation of pyruvate?

 A) Pyruvate reacts with the bound thiamine pyrophosphate (TPP) of pyruvate dehydrogenase, undergoing decarboxylation to the hydroxyethyl derivative

 B) A transesterification in which the —SH group of CoA replaces the —SH group of E2 to yield acetyl-CoA and the fully reduced (dithiol) form of the lipoyl group

 C) The reduced FADH2 of E3 transfers a hydride ion to NAD1 , forming NADH, the enzyme complex is now ready for another catalytic cycle

 D) The transfer of two electrons and the acetyl group from TPP to the oxidized form of the lipoyllysyl group of the core enzyme, dihydrolipoyl transacetylase, to form the acetyl thioester of the reduced lipoyl group

 E) Dihydrolipoyl dehydrogenase promotes transfer of two hydrogen atoms from the reduced lipoyl groups of E2 to the FAD prosthetic group of E3 , restoring the oxidized form of the lipoyllysyl group of E2

 Find out the correct sequence of action of this complex enzyme?

#Unit 6. System Physiology – Plant
  1. E→C→B→E→D
  2. A→D→B→E→C
  3. E→B→D→A→C
  4. D→A→E→B→C
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TLS Online TPP Program

#Question id: 27071

#Unit 1. Molecules and their Interaction Relevant to Biology

Bond forces and their strength are given match them correctly 

 Force Strength (kJ/mol) 
 1. Van der Waals interactions a. <40
 2. Hydrogen bonds b. 20
 3. Ionic interactions c. 12–30
 4. Hydrophobic interactions d. 0.4–4.0
TLS Online TPP Program

#Question id: 823

#Unit 1. Molecules and their Interaction Relevant to Biology

chaotropic agents such as guanidinium ion and urea, the efficiency of the chaotropic agent is measured in terms of-
TLS Online TPP Program

#Question id: 13001

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following is incorrect 
a) antiparallel β sheets are frequently found and they are quite more stable because of more no. hydrogen bond presence and linear H bonding pattern.
b) antiparallel β sheets are frequently found and they are quite more stable because of more no. hydrogen bond presence and having distorted H bonding pattern.
c) parallel β sheets are relatively less stable and mostly found in core of protein.
d) parallel β sheets are relatively more stable and mostly found in core of protein.
TLS Online TPP Program

#Question id: 13000

#Unit 1. Molecules and their Interaction Relevant to Biology

Identify the correct statement regarding the structure
TLS Online TPP Program

#Question id: 12999

#Unit 1. Molecules and their Interaction Relevant to Biology

Proline and glycine both disturb the symmetry of α-helix which of the following are true regarding to these two amino acids
a) proline changes the orientation of hetropolymeric α-helix hence proline can be placed only as 1st amino acid residue near to C-terminus 
b) proline changes the orientation of polymeric α-helix hence proline can be placed only as 1st amino acid residue near to N-terminus
c) glycine disrupts the heteropolymeric α-helix by changing the helicity.
d) homopolymer of proline and glycine can form stable helix. 
TLS Online TPP Program

#Question id: 12998

#Unit 1. Molecules and their Interaction Relevant to Biology

Match with appropriate bonding pattern

Helix typeHydrogen bonding
a. α-helix1. n, n+3
b. 310 helix2. n, n+5
c. π helix3. n, n+4