In 2001, the Nobel Prize in Physiology or Medicine was awarded to three cell cycle scientists. Paul Nurse was recognized for his studies with the fission yeast S. pombe, in particular for the discovery and characterization of the wee1+ gene. What did the characterization of the wee1+ gene tell us about cell cycle control?

#Question id: 10350

#Unit 6. System Physiology – Plant

Ammonium can be assimilated via an alternative pathway rather than primary pathway which involves the sequential actions of glutamine synthetase(GS) and glutamate synthase(GOGAT), these alternative pathway catalyzes by enzyme known as,

#Question id: 10351

#Unit 6. System Physiology – Plant

Plants contain two types of GOGAT; one accepts electrons from NADH, and the other accepts electrons from ferredoxin (Fd); which one of the following statements is correct?

#Question id: 10352

#Unit 6. System Physiology – Plant

which of the following amino acid that participates in the malate–aspartate shuttle to transfer reducing equivalents from the mitochondrion and chloroplast into the cytosol?

#Question id: 10353

#Unit 6. System Physiology – Plant

Aminotransferases are found in multiple organelles such as cytoplasm, chloroplasts, mitochondria, glyoxysomes, and peroxisomes, these aminotransferases one of its organelles may have a significant role in amino acid biosynthesis such as;

#Question id: 10354

#Unit 6. System Physiology – Plant

One of the enzyme that are involve in the ammonium assimilation is Asparagine synthetase (AS), some statements given below about AS such as,

a) This enzyme that catalyzes this reaction, is found in the cytosol of leaves and roots and in nitrogen-fixing nodules

b) High levels of light and carbohydrate inhibit the expression of genes coding for AS and the activity of the enzyme

c) Conditions of ample energy stimulate AS, thus they favor nitrogen assimilation into glutamine and glutamate

d) Energy-limited conditions inhibit GS and GOGAT, stimulate AS, and thus favor nitrogen assimilation into asparagine, a compound that is rich in nitrogen and sufficiently stable for long-distance transport or long term storage

Which of the following statements about AS is correct?

#Question id: 10355

#Unit 6. System Physiology – Plant

The conversion of ammonium to amino acids requires two enzymes such as GS and GOGAT,

a) High levels of light and carbohydrate—conditions that stimulate plastid GS and Fd-GOGAT

b) Conditions of ample energy inhibit GS and GOGAT

c) The stimulation of GS and GOGAT, they favor nitrogen assimilation into glutamine and glutamate, compounds that are rich in carbon and participate in the synthesis of new plant materials

d) In energy-limited conditions inhibit GS and GOGAT

Which of the following statements about GS and GOGAT is correct?