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?

TLS Online TPP Program

#Question id: 10476

#Unit 1. Molecules and their Interaction Relevant to Biology

Following statements are regarding to gangliosides.

A. They are ceramides with attached oligosaccharides that include at least one sialic acid residue.

B. They are ceramides with attached oligosaccharides that include at least one phasphatidic acid residue.

C. Sialic acid gives gangliosides the negative charge at pH 7 that distinguishes them from globosides.

D. Gangliosides are primarily components of cell-surface membranes and constitute a significant fraction (6%) of brain lipids.

Which of the following combination is correct?

TLS Online TPP Program

#Question id: 10475

#Unit 1. Molecules and their Interaction Relevant to Biology

During the formation of a blood plasma protein The aromatic ring of vitamin K undergoes:

TLS Online TPP Program

#Question id: 10474

#Unit 1. Molecules and their Interaction Relevant to Biology

Lipids differ from other large biological molecules in that they

TLS Online TPP Program

#Question id: 10473

#Unit 1. Molecules and their Interaction Relevant to Biology

Cleavage of beta-carotene by BCMO1 yields two molecules of :

TLS Online TPP Program

#Question id: 10321

#Unit 1. Molecules and their Interaction Relevant to Biology

The human blood groups (O, A, B) are determined in part by the oligosaccharide head groups of these glycosphingolipids. Which of the following is correct?

TLS Online TPP Program

#Question id: 10320

#Unit 1. Molecules and their Interaction Relevant to Biology

Following statements are regarding to archaeal lipids.

A. archaea have membrane lipids containing long-chain (32 carbons) branched hydrocarbons linked at each end to glycerol.

B. archaeal lipids are twice the length of phospholipids and sphingolipids, and can span the full width of the plasma membrane.

C. In archaeal lipids, at each end of the extended molecule is a polar head consisting of glycerol linked to either phosphate or sugar residues.

D. The glycerol moiety of the archaeal lipids is same as the stereoisomer as that in the lipids of bacteria and eukaryotes.

Which of the following statement is incorrect?