According to a recent model, the balance between the activities of ABA and gibberellin in seeds is under both developmental and environmental control such as

a) early stages of seed development, ABA sensitivity is high and gibberellin sensitivity is low, which favors dormancy over germination

b) Later in seed development, ABA sensitivity declines and gibberellin sensitivity increases, favoring germination.

c) Environmental factors such as temperature  and light affect the ABA:GA ratios by activation of the  NCED and GA2ox enzyme, which promotes seed dormancy

d) During an Ambient environment, activation of GA3ox and CYP707A2 inducing dormancy

Which of the following combination  from the above statements is incorrect?

#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 _________.

#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:

#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?

#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:

#Question id: 622

#Unit 1. Molecules and their Interaction Relevant to Biology

An enzyme-catalyzed reaction was carried out with the substrate concentration initially a thousand times greater than the Km for that substrate.  After 9 minutes, 1% of the substrate had been converted to product, and the amount of product formed in the reaction mixture was 12 micromol.  If, in a separate experiment, one-third as much enzyme and twice as much substrate had been combined, how long would it take for the same amount (12 micromol) of product to be formed?

#Question id: 623

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of these statements about enzyme-catalyzed reactions is false?