Create
Learn
Share

25

rename
cokawagu's version from 2015-05-01 05:26

Summary

This page helps you learn capitals of countries.

Countries

Question Answer
FranceParis
RussiaMoscow
memorize

 

Replace all words in this box with the content you want to create (including this sentence). Then add, delete, and edit the text as desired.
Question Answer
1. What is nitrogen fixation? A. The reduction of NO3- to NH4+.B. The formation of NH4+ from N2 gas.C. The oxidation of NH4+ to N2.D. The oxidation of NH4+ to NO3-.E. The formation of NO2- from NO3-B The formation of NH4+ from N2 gas
memorize
2. Animals are totally dependent on plants and microorganisms for nitrogen fixation and nitrate assimilation because animals
A. do not have the reducing power (NADPH) to fix nitrogen.
B. lack the enzyme aminotransferase.
C. lack the enzymes to reduce N2 and NO3- to NH4+.
D. lack carbamoyl-phosphate synthetase I.
Question Answer
E. lack glutamate dehydrogenase.C lack the enzymes to reduce N2 and NO3- to NH4+
3. Nitrifying bacteria obtain their chemical energy from: D The oxidation of NH4+ to NO3-E. the formation of NO2-from NO3-.
memorize
A. the reduction of NO3-to NH4+.
B. the formation of NH4+ from N2 gas.
C. the oxidation of NH4+ to N2.
D. the oxidation of NH4+ to NO3-.

 

Question Answer
4. Denitrifying bacteria are capable of all EXCEPTC Oxidizing NH4+ to NO3-
memorize
A. reducing NO3- to N2.
B. using NO3- as an electron acceptor in their energy-producing pathways.
C. oxidizing NH4+to NO3-.
D. reducing the combined-nitrogen levels.
E. being utilized in water treatment plants to reduce nitrogen entering lakes and streams.

 

Question Answer
5. Nitrate assimilation occurs in two steps: reduction of nitrate to ____ and further reduction to ____D Nitrite; ammonia
memorize

 

A. ammonia; nitrogen
B. nitrogen; ammonia
C. nitrite; nitrogen
D. nitrite; ammonia
E. none are correct
Question Answer
6. The correct sequence for electron-transport in nitrate reductase isA,B,C,D,E,F
memorize

 

A. NADH
B. -SH
C. FAD
D. Cyt b557
E. MoCo
F. NO3-
Question Answer
7. Nitrite reductase requires ____ electrons to reduce NO2- to NH4+and the electrons are provided in higher plants through photosynthesis as reduced ____. E 6; ferredoxin
memorize
A. 2; plastoquinone
B. 3; plastoquinone
C. 4; heme
D. 5; heme
E. 6; ferredoxin

 

Question Answer
8. Nitrogen fixation involves the enzyme ____ catalyzing the reaction N2 + 10 ____ + ____ e- ® 2 NH4+ + H2 B
memorize
A. nitrate reductase; H2O; 6
B. nitrogenase; H+; 8
C. nitrogenase; H+; 2
D. nitrogen reductase; H2O; 6
E. none are true
Question Answer
9. All N2-fixing systems are nearly identical and have all of the requirements EXCEPTE all are true
memorize
A. ATP.
B. O2-free conditions.
C. the enzyme nitrogenase.
D. strong reductant such as ferredoxin.
E. all are true.
Question Answer
10. The involvement of ATP in the nitrogenase complex is because ATP is needed toC break the N2 triple bond
memorize
A. provide electrons.
B. phosphorylate the enzyme.
C. break the N2 triple bond.
D. transfer electrons from ferredoxin.
E. all are true.

 

Question Answer
11. Control over nitrogenase activity is accomplished by which of the following?C NH4+ prevents expression of the genes that encode nitrogenase
memorize

 

A. ATP serves as an allosteric activator
B. AMP serves as an allosteric inhibitor
C. NH4+ prevents expression of the genes that encode nitrogenase
D. phosphorylation prevents activity
E. none of the above
Question Answer
13. What reaction does glutamate dehydrogenase (GDH) catalyze?A The reductive amination of alpha-ketoglutarate to yield glutamate
memorize
A. The reductive amination of a-ketoglutarate to yield glutamate.
B. Phosphorylation of carbamate to yield carbamoyl-phosphate.
C. The amidation of the g-carboxyl group of glutamate to form glutamine.
D. The deadenylation of glutamine synthetase.
E. The adenylation of glutamine synthetase.

 

Question Answer
14. The reaction, glutamate + NAD(P)+ + H2O ® NH4+ + a-ketoglutarate + NAD(P)H + H+, is catalyzed byC Glutamate dehydrogenase (GDH)
memorize
A. Nitrogenase.
B. carbamoyl-phosphate synthetase (CPS-I).
C. glutamate dehydrogenase (GDH).
D. glutamine synthetase (GS).
E. none are true.

 

Question Answer
15. Glutamine synthetase (GS) belongs to what class of enzymes?E
memorize
A. isomerases
B. oxidoreductase
C. ligase
D. lyase
E. transferase

 

Question Answer
16. The reaction, 2 NH4+ + a-ketoglutarate + NADPH + ATP  glutamine + NADP+ + ADP + Pi + H2O, is the combined result of what two enzymes?B Glutamate dehydrogenase and glutamine synthetase
memorize

 

A. nitrogenase and glutamate dehydrogenase
B. glutamate dehydrogenase and glutamine synthetase
C. glutamine synthetase and nitrogenase
D. glutamate dehydrogenase and nitrogenase
E. all are correct
Question Answer
17. Glutamate synthase (GOGAT) catalyzes the reaction ____ + ____ + ____  2 glutamate + NADP+A alpha-ketoglutarate, NADPH, glutamine
memorize
A. a-ketoglutarate; NADPH; glutamine
B. glutamate; a-ketoglutarate; NADH
C. glutamyl-phosphate; glutamine; NADPH
D. N-acetylglutamate; a-ketoglutarate; NADH
E. none are true
Question Answer
18. Bacterial glutamine synthetase (GS) monomers are inactive because they must beC stacked for interface active site development
memorize
A. phosphorylated for activity.
B. activated by binding glutamine.
C. stacked for interface active site development.
D. combined for allosteric regulation.
E. none are true.

 

Question Answer
19. All of the following act in feedback inhibition of glutamine synthetase (GS) in prokaryotes EXCEPTD Proline
memorize
A. AMP.
B. glucosamine-6-phosphate.
C. histidine.
D. proline.
E. CTP.

 

Question Answer
20. All of the following are characteristic features of ATP:GS:adenylyl transferase (AT) EXCEPTB It exists in two forms, PIIA and PIID. PIIA causes the deadenylation of glutamine synthetase and its activity increases with an increase in glutamine
memorize
A. It catalyzes the adenylation of glutamine synthetase.
B. It exists in two forms, PIIA and PIID. PIIA causes the deadenylation of glutamine synthetase and its activity increases with an increase in glutamine.
C. AT:PIIA is inhibited by a-ketoglutarate.
D. AT:PIIA needs ATP to complete the reaction.
E. It is an enzyme that causes the adenylation/deadenylation of a specific tyrosine residue

 

Question Answer
21. What would be a result of a high [Gln]/[a-KG] ratio?C An increase in the degree of adenylation of glutamine synthetase
memorize
A. Increase in deadenylation of glutamine synthetase.
B. An increase in activity of glutamine synthetase.
C. An increase in the degree of adenylation of glutamine synthetase.
D. Inhibition of AT:PIIAand stimulation of AT:PIID.
E. A need for ammonium fixation by glutamine synthetase.
Question Answer
22. In plants and microorganisms, amino acid biosynthesis is a matter of synthesizing the appropriate ____ followed by transamination with ____B alpha-ketoacid; glutamate
memorize
A. acetyl-CoA derivatives; glutamine
B. a-ketoacid; glutamate
C. phospho-carbon skeleton; alanine
D. nitrogenous base; glutamate
E. none are true

 

Question Answer
23. In the process of amino acid biosynthesis, how are glutamic acid, glutamine, proline, and arginine all related?A They are all derived from alpha-KG
memorize
A. They are all derived from a-KG.
B. They are all derivatives of acetyl CoA.
C. They are all derivatives of pyruvate.
D. They are all derived from aspartate.
E. They are all derivatives of 3-phosphoglycerate.

 

Question Answer
24. All of the following are true of transamination EXCEPTC The coenzyme needed is thiamin pyrophosphate (TPP)
memorize
A. It is characterized by the transfer of an a-amino group from an amino acid to the a-keto position of an a-keto acid.
B. The amino donor becomes an a-keto acid.
C.The coenzyme needed is thiamin pyrophosphate (TPP).
D. The a-keto acid acceptor becomes an a-amino acid.

 

Question Answer
25. Which of the following is an essential amino acid?B Valine
memorize
A. proline
B. valine
C. glutamine
D. aspartate
E. glycine
Question Answer
26. Which of the following is NOT a commonly used transamination pair?B Asp/Oxaloacetate
memorize
A. Phe / phenylpyruvate
B. Asp / oxaloacetate
C. Glu / a-ketoglutarate
D. Ala / pyruvate
E. all are correct

 

Question Answer
27. ____ is an intermediate in biosynthesis of ornithine and a regulator of carbamoyl-phosphate synthetase-IC N-acetylglutamate
memorize
A. g-Glutamyl-phosphate
B. a-Ketoglutarate
C. N-Acetylglutamate
D. Glutamine
E. Glutamine-5-phosphate

 

Question Answer
28. All of the carbons and nitrogens of ornithine come biosynthetically fromD Glutamate
memorize
A. proline.
B. valine.
C. alanine.
D. glutamate.
E. glycine.

 

Question Answer
29. Ornithine serves three metabolically important roles, but is not found in proteins. What is one of the important roles of ornithine?B An intermediate in the urea cycle
memorize
A. precursor in the synthesis of aspartate
B. an intermediate in the urea cycle
C. formation of ornithine from serine
D. it condenses with aspartate to form argininosuccinate
E. it is derived from glutamate-5-phosphate

 

Question Answer
30. All of the following are true of the urea cycle EXCEPTD Stimulation of carbamoyl-phosphate synthetase I (CPS-I) decreases the activity of the urea cycle
memorize

 

A. It helps in the excretion of excess nitrogen.
B. It is mainly confined to the liver.
C. It is linked to the citric acid cycle through fumarate.
D. Stimulation of carbamoyl-phosphate synthetase I (CPS-I) decreases the activity of the urea cycle.
E. It is completed by the regeneration of ornithine from arginine.
Question Answer
31. Which of the following directly serves as one of the nitrogen atoms of a urea molecule?B the N of Asp
memorize
A. the amide N of Asn
B. the N of Asp
C. the R-group N of Lys
D. the N of glucosamine
E. none of the above

 

Question Answer
32. Aspartate is formed from transamination ofC Oxaloacetate
memorize
A. asparagine.
B. aspartame.
C. oxaloacetate.
D. citrate.
E. a-ketoglutarate.

 

Question Answer
33. Homoserine and homocysteine are related to serine and cysteine by havingB An additional methylene group
memorize
A. an extra amino group.
B. an additional methylene group.
C. an additional carboxyl group.
D. an aldehyde group.
E. a phosphoryl group.

 

Question Answer
34. Amino acids biosynthesized from aspartate include all EXCEPTE Glutamate
memorize
A. asparagine.
B. threonine.
C. methionine.
D. lysine.
E. glutamate.

 

Question Answer
36. Transamination of pyruvate with glutamate as amino donor givesA Alanine
memorize
A. alanine.
B. serine.
C. cysteine.
D. aspartate.
E. valine.

 

Question Answer
37. All of the following are true statements regarding the 3-Phosphoglycerate (3-PG) family EXCEPTA 3-PG is diverted from glycolysis by phosphoglycerate mutase
memorize
A. 3-PG is diverted from glycolysis by phosphoglycerate mutase.
B. Glycine can be derived from serine.
C. Serine, glycine and cysteine are all nonessential amino acids.
D. Production of glycine also produces N5, N10-methylene-THF which is important in the biosynthesis of purines.
E. Serine production is regulated by a direct feedback mechanism.
Question Answer
38. Chorismate biosynthesis occurs via the shikimate pathway and is an important precursor in the synthesis of all of the following EXCEPTC threonine
memorize
A. vitamin K.
B. folic acid.
C. threonine.
D. tyrosine.
E. tryptophan.

 

Question Answer
39. Herbicides (e.g., "Roundup") that inhibit biosynthesis of "essential" amino acids should be relatively safe for animal exposure because animals do not have enzymes ofD Phe, Val, Leu, Ile, and His biosynthetic pathways
memorize
A. photosynthesis.
B. glyoxylate cycle.
C. glutamine synthesis pathway.
D. Phe, Val, Leu, Ile and His biosynthetic pathways.
E. none are correct.

 

Question Answer
40. All are convergent metabolic intermediates of a-amino acid carbon skeletons EXCEPTA Citrate
memorize

 

A. Citrate.
B. a-ketoglutarate.
C. Oxaloacetate.
D. succinyl-CoA.
E. Fumarate.
Question Answer
41. The term ketogenic amino acids refers to amino acidsB degraded to yield acetyl CoA
memorize
A. that are precursors for glucose synthesis.
B. degraded to yield acetyl CoA or acetoacetate.
C. that can not be converted to fatty acids or ketone bodies.
D. degraded to yield succinyl-CoA, pyruvate, a-ketoglutarate, fumarate and oxaloacetate.
E. none of the above.

 

Question Answer
42. The carbon skeletons of all of the amino acids below converge to pyruvate EXCEPTE glutamate
memorize
A. alanine.
B. serine.
C. cysteine.
D. glycine.
E. glutamate.

 

Question Answer
43. Degradation of valine, isoleucine and methionine leads to succinyl-CoA via the sequence ofE,A,C,D,C,B
memorize
A. carboxylation using biotin and ATP
B. mutase
C. methylmalonyl-CoA
D. epimerase
E. Propionyl-CoA