Galactose imported into the yeast cell is converted to galactose 6-phosphate by a pathway involving six enzymes, whose genes are scattered over three chromosomes. Transcription of these genes is regulated by the combined actions of the proteins Gal4p, Gal80p, and Gal3p,

i. GAL3	a. Interaction with the Gal80p-Gal4p complex and activates Gal4p.
ii. GAL4	b. Recruits SAGA, Mediator, and TFIID to the galactose promoters, leading to DNA polymerase II recruitment and initiation of transcription
iii. GAL80	c. Transcriptional inhibitor
	d. Transcriptional activator

#Question id: 10339

#Unit 6. System Physiology – Plant

Nitrate assimilates into the root where the conversion of nitrate to nitrite in the cytosol, a reduction reaction that involves the transfer of two electrons catalyzes by an enzyme that is NAD(P)H dependent is known as

#Question id: 10340

#Unit 6. System Physiology – Plant

There several charecteristics of nitrate reductase, which of the following properties of nitrate reductase is incorrect?

#Question id: 10341

#Unit 6. System Physiology – Plant

The accumulation of nitrate that results from diminished nitrate reductase activity, this symptoms is caused by

#Question id: 10342

#Unit 6. System Physiology – Plant

Nitrate reductase is an important enzyme for nitrate assimilation. Given below some regulation of nitrate reductase activity through phosphorylation and dephosphorylation.

a) Light, and other environmental factors stimulate a protein phosphatase that dephosphorylates a key serine residue in the hinge 1 region of nitrate reductase and thereby activates the enzyme

b) In Dark, and Mg2+ stimulate a protein kinase that phosphorylates the same serine residues, which then interact with a 14-3-3 inhibitor protein, and thereby inactivate nitrate reductase

c) In Light, and Mg2+ stimulate a protein kinase that phosphorylates the serine residues, and thereby activate nitrate reductase

d) In Dark, and other environmental factors stimulate a protein phosphatase that dephosphorylates a key serine residue in the hinge 1 region of nitrate reductase and thereby inactivates the enzyme

Which of the following statements about regulation of nitrate reductase is correct?

#Question id: 10343

#Unit 6. System Physiology – Plant

In many plants, nitrate is assimilated in the root as well as in the shoot according to their native place. Some of the given statements about nitrate assimilation;

a) If plants native to temperate region assimilate NO3^- at root

b) If plants native to temperate region assimilate NO3^- at shoot

c) Plants native to tropical or subtropical region assimilate NO3^- at root

d) Plants native to tropical or subtropical region assimilate NO3^- at shoot

Which of the following combination from above statements is correct?

#Question id: 10344

#Unit 6. System Physiology – Plant

Some of the following caracteristics of Nitrite reductase, which one of the is incorrect?