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: 11899

#General Aptitude

#Question id: 11900

#General Aptitude

#Question id: 11901

#General Aptitude

#Question id: 11902

#Unit 6. System Physiology – Plant

A chemiosmotic model  has been proposed  to explain Polar transport , following steps are involve in the transport of auxin polarly;

a) IAA enters the cell either passively in the undissociated form (IAAH) or by secondary active cotransport in the anionic form (IAA–)

b) The cell wall is maintained at an acidic pH by the activity of the plasma membrane H+- ATPase

c) In the cytosol, which has acidic pH, the IAAH form predominates

d) The anions exit the cell via auxin anion efflux carriers that are concentrated at the basal ends of each cell in the longitudinal pathway

Which of the following is the correct statements about the polarly transporting of auxin?

#Question id: 11903

#Unit 7. System Physiology – Animal

If a patient has a creatinine clearance of 90 ml/min, a urine flow rate of 1 ml/min, a plasma K+ concentration of 4 mEq/L, and a urine K+ concentration of 60 mEq/L, what is the approximate rate of K+ excretion?

#Question id: 11904

#Unit 7. System Physiology – Animal

Which of the following changes would be expected in a patient with diabetes insipidus due to a lack of antidiuretic hormone (ADH) secretion?