The Chemical Structure of ABA Determines Its Physiological Activity, 15 carbon compound 

a) The orientation of the carboxyl group at carbon 2 determines the cis and trans isomers of ABA. Nearly all the naturally occurring ABA is in the cis form

b) S enantiomer is the natural form; commercially available synthetic  ABA is a mixture of approximately equal amounts of the S and R forms.

c) The S enantiomer is the only one that is active in fast responses to ABA, such as stomatal closure

d) In long-term responses, such as seed maturation, only R-enantiomers are active

e) In contrast to the cis and trans isomers, the S and R forms cannot be interconverted in the plant tissue

Which of the following is the correct prediction about the active form  of ABA?

#Question id: 861

#Unit 1. Molecules and their Interaction Relevant to Biology

Alexander Varshavsky discovered, the half-lives of many cytoplasmic proteins vary with the identities of their N-terminal residues via the so-called N-end rule:-

#Question id: 860

#Unit 1. Molecules and their Interaction Relevant to Biology

Select true ‘T’ AND false ‘F’ about ubiquitinylation

I. These ubiquitin-like modifiers control processes as diverse as nuclear import,

II. Regulated by the ubiquitin-like modifier Sumo, and autophagy,

III. Regulated by the ubiquitin-like modifier Atg8.

IV. For a protein to be efficiently degraded, it must be linked to a chain of at least four tandemly linked ubiquitin molecules in which Lys 34 of each ubiquitin forms an isopeptide bond with the C-terminal carboxyl group of the following ubiquitin.

#Question id: 654

#Unit 1. Molecules and their Interaction Relevant to Biology

Which pair represents different conformations?

#Question id: 655

#Unit 1. Molecules and their Interaction Relevant to Biology

A change from one conformation of a molecule to another involves ________.

#Question id: 656

#Unit 1. Molecules and their Interaction Relevant to Biology

The ________ is the single shape a protein adopts under physiological conditions.

#Question id: 657

#Unit 1. Molecules and their Interaction Relevant to Biology

Structural proteins that typically assemble into large cables or threads to provide mechanical support to cells or organisms are classified as ________ proteins.