During ammonium assimilation, requires two enzymes converting ammonium to amino acids. Each of which is Glutamine synthetase (GS), given below some statements about GS ;

a) GS transfers the amide group of glutamine to 2-oxoglutarate, yielding two molecules of glutamate

b) it requires a divalent cation such as Mg2+, Mn2+, or Co2+ as a cofactor

c) Plants contain two classes of GS, one in the cytosol and the other in root plastids or shoot chloroplasts

d) The cytosolic forms are expressed in germinating seeds or in the vascular bundles of roots and shoots and produce glutamate for intercellular nitrogen transport

e) The GS in root plastids generates amide nitrogen for local consumption; the GS in shoot chloroplasts reassimilates photorespiratory NH4+

f) Light and carbohydrate levels alter the expression of the cytosolic forms of the enzyme, but they have little effect on the plastid forms.

Which of the following statements is correct?

#Question id: 10493

#Unit 6. System Physiology – Plant

Which wavelength modulates guard cell osmoregulation by means of its activation of proton pumping, solute uptake, and stimulation of the synthesis of organic solutes;

#Question id: 10491

#Unit 6. System Physiology – Plant

Acidification of the lumen stimulates zeaxanthin formation, and alkalinization favors violaxanthin formation. Lumen pH depends on photosynthetic photon flux density, most effective at

#Question id: 10490

#Unit 6. System Physiology – Plant

Which of the following is a correct Match of the stomatal opening and closing mechanism;

#Question id: 10489

#Unit 6. System Physiology – Plant

Malate anions, by contrast, are synthesized in the guard cell cytosol, in a metabolic pathway that uses carbon skeletons generated by

#Question id: 10488

#Unit 6. System Physiology – Plant

Blue light activates a proton pump at the guard cell plasma membrane. The relationship between proton pumping at the guard cell plasma membrane and stomatal opening is evident from the observations that;

 a.) Orthovandate inhibits the fusicoccin-stimulated opening

 b.) fusicoccin stimulates both proton extrusion from guard cell protoplasts and stomatal opening

 c.) CCCP inhibits the fusicoccin-stimulated opening

 d.) CCCP, a proton ionophore that makes the plasma membrane highly permeable to protons resulting stomatal opening

 Which one of the following observation from the above statements should  be correct?

#Question id: 10487

#Unit 6. System Physiology – Plant

During the patch clamp experiments measure outward electric current in picoamps, pA at the plasma membrane of a guard cell protoplast stimulated by two points A and B showing in the graph.

What is A and B