Many G protein-coupled receptors contain seven transmembrane α-helical domains. The amino end of the protein lies at the exterior of the plasma membrane. Loops of amino acids connect the helices either at the exterior surface or on the cytosolic surface of the membrane. The loop on the cytosolic side between helices 5 and 6 is usually substantially longer than the others. Where would a coupled G protein most likely interact with this receptor?

#Question id: 10792

#Unit 6. System Physiology – Plant

Compounds such as caffeic acid and ferulic acid occur in soil in appreciable amounts and have been shown,

#Question id: 10793

#Unit 6. System Physiology – Plant

Hydroxyl groups (−OH),  and methoxy groups(−OCH3) modification provides colour variations in case of

#Question id: 10794

#Unit 6. System Physiology – Plant

Which one of the following characteristics of about lignin is incorrect?

#Question id: 10795

#Unit 6. System Physiology – Plant

basic carbon skeleton of a flavonoid contains 15 carbons arranged in two aromatic rings connected by a three-carbon bridge. This structure results from two separate biosynthetic pathways:

#Question id: 10796

#Unit 6. System Physiology – Plant

Flavonoids are one of the largest classes of plant phenolics, structure of flavonoids;

#Question id: 10797

#Unit 6. System Physiology – Plant

The colored pigments of plants are of two principal types: carotenoids and flavonoids. Given below some statements of about these pigments;

 a) Anthocyanins are colored flavonoids that attract animals

b) Flavonoids are phenolic compounds that include a wide range of colored substances

c) Carotenoids are coloured terpenoid compounds that also serve as accessory pigments in photosynthesis

d) most widespread group of pigmented carotenoids is the anthocyanins, these are glycosides that have sugars. Without their sugars, anthocyanins are known as anthocyanidins

Which of the following is incorrect statements of these pigments;