TLS Online TPP Program

#Question id: 5663


Following statements are related to slow block to polyspermy in mammals.

A. A First slow block to polyspermy comes When the cortical granules fuse with the egg cell membrane, they release protein-digesting enzymes which is called as ovastacin that modify the zona pellucida proteins.

B. A second slow block to polyspermy comes from the so-called zinc spark, the release of billions of zinc ions that is induced by the entry of the first sperm, these released zinc ions are seen to bind to the egg cell membrane form a “zinc shield” that prevents further sperm entry.

C. A third slow block to polyspermy occurs at the level of the egg cell membrane and involves Juno.

Which of the following is incorrect?

#Unit 5. Developmental Biology
  1. A, B and C

  2. B only

  3. A and B

  4. A and C

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TLS Online TPP Program

#Question id: 621

#Unit 1. Molecules and their Interaction Relevant to Biology

Michaelis and Menten assumed that the overall reaction for an enzyme-catalyzed reaction could be written as Using this reaction, the rate of breakdown of the enzyme-substrate complex can be described by the expression:

TLS Online TPP Program

#Question id: 620

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following statements about a plot of V0 vs. [S] for an enzyme that follows Michaelis-Menten kinetics is false?

TLS Online TPP Program

#Question id: 619

#Unit 1. Molecules and their Interaction Relevant to Biology

The benefit of measuring the initial rate of a reaction V0 is that at the beginning of a reaction:

TLS Online TPP Program

#Question id: 618

#Unit 1. Molecules and their Interaction Relevant to Biology

 In the following diagram of the first step in the reaction catalyzed by the protease chymotrypsin, the process of general base catalysis is illustrated by the number ________, and the process of covalent catalysis is illustrated by the number _________.

TLS Online TPP Program

#Question id: 617

#Unit 1. Molecules and their Interaction Relevant to Biology

Compare the two reaction coordinate diagrams below and select the answer that correctly describes their relationship.  In each case, the single intermediate is the ES complex.

TLS Online TPP Program

#Question id: 616

#Unit 1. Molecules and their Interaction Relevant to Biology

Which equilibrium below applies to noncompetitive inhibition?