Following statements are regarding to the molecular basis of the coincidence model in Arabidopsis.

A. In Arabidopsis under short days, there is little overlap between CO mRNA expression and daylight.

B. CO protein does not accumulate to sufficient levels in the phloem to promote the expression of the transmissible floral stimulus and the plant remains vegetative.

C. Under long days, the peak of CO mRNA abundance (at hours 12 through 16) overlaps with daylight (sensed by phyA and cryptochrome [cry]), allowing CO protein to accumulate.

D. CO activates FLC mRNA expression in the phloem, which causes flowering when the FT protein is translocated to the apical meristem.

Which of the following is incorrect?

#Question id: 597

#Unit 1. Molecules and their Interaction Relevant to Biology

The Km values for enzyme reactions such as A + B → C + D

#Question id: 598

#Unit 1. Molecules and their Interaction Relevant to Biology

Which might be a method used for distinguishing among several mechanistic possibilities in a multi-substrate reaction?

#Question id: 599

#Unit 1. Molecules and their Interaction Relevant to Biology

In a certain enzyme-catalyzed reaction the following steps occur:

1. A phosphate group on substrate A is transferred to a side chain of an active site residue of the enzyme.

2. The dephosphorylated form of substrate A dissociates from the enzyme.

3. Substrate B enters the active site and is phosphorylated with simultaneous regeneration of the enzyme in its original form.

What kind of kinetic mechanism is described?

#Question id: 600

#Unit 1. Molecules and their Interaction Relevant to Biology

Two substances are used to produce a certain biological product in an enzyme-catalyzed reaction. It is found that both substrates must bind to the enzyme, first one, then the other before the product is produced. This is an example of a/an ________.

#Question id: 601

#Unit 1. Molecules and their Interaction Relevant to Biology

In a ping-pong reaction which does not occur?

#Question id: 602

#Unit 1. Molecules and their Interaction Relevant to Biology

An inhibitor binds to a site other than the active site of the enzyme. Which statement below correlates with this observation?