Multiple  isoforms of ethylene receptors may be present in a cell. The receptor is a dimer, held together by______X_________. Ethylene binds within the transmembrane domain, through________Y______, which is assembled into the ethylene receptors.

#Question id: 12585

#Unit 10. Ecological Principles

#Question id: 14523

#Unit 13. Methods in Biology

#Question id: 12801

#Unit 10. Ecological Principles

#Question id: 12048

#Unit 7. System Physiology – Animal

#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?