Electrons ejected from chlorophyll travel through a series of electron carriers organized in the “Z Scheme” shows a current version of the Z scheme, in which all the electron carriers known to function in electron flow from H2O to NADP Presented in the following sequence;

a.) P680 reduce by Yz has received electrons from oxidation of water P680→P680*→pheophytin→ plastoquinones→ cytochrome b6 f complex→ plastocyanin→ in turn reduces (PSI) P700+

b.) P700+→ P700*→ membrane-bound iron–sulfur proteins → A0→ A1 → flavoprotein ferredoxin–NADP reductase (FNR) soluble → ferredoxin(Fd) → NADP+ to NADPH

c.) P700+→ P700*→ A0→ A1→ membrane-bound iron–sulfur proteins→ ferredoxin(Fd)→ soluble flavoprotein ferredoxin–NADP reductase (FNR)→ NADP+ to NADPH

d.) P680 reduce by Yz has received electrons from oxidation of water P680→P680*→ plastoquinones → pheophytin → cytochrome b6 f complex→ plastocyanin→ in turn reduces (PSI) P700+

Which one of the following combinations is correct?

#Question id: 10337

#Unit 6. System Physiology – Plant

In biological nitrogen fixation, the process of nitrification by organism respective bacteria A--which convert the ammonia to nitrite and B--- further converted into nitrate in the soil by their respective A and B bacteria known as;

#Question id: 10338

#Unit 6. System Physiology – Plant

Nitrate from the soil solution actively absorb by Plant roots via several low- and high-affinity transporters known as

#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?