Question 1

How does biological fixation convert nitrogen to ammonia?

Accepted Answer

A)  by reducing nitrogen 
B)  by combining nitrogen with carbon 
C)  through the ATP-dependent process catalyzed by nitrogenase complex 
D)  through the NADH-dependent process catalyzed by glutamate dehydrogenase 
A)  by reducing nitrogen 
B)  by combining nitrogen with carbon 
C)  through the ATP-dependent process catalyzed by nitrogenase complex 
D)  through the NADH-dependent process catalyzed by glutamate dehydrogenase

Question 2

Which of the following is the reaction for nitric oxide synthase?

Accepted Answer

A)  citrulline + NO + 1.5 NADP+ $\rightarrow$L-arginine + 1.5 NADPH + H+ + 2O2 
B)  L-arginine + 1.5 NADPH + H+ + 2O2$\rightarrow$ citrulline + NO + 1.5 NADP+ 
C)  L-arginine + 1.5 NADPH + H+ + 2O2$\rightarrow$ dopamine + NO + 1.5 NADP+ 
D)  L-arginine + 1.5 NADP+ + H+ + 2O2$\rightarrow$ citrulline + NO + 1.5 NADPH 
A)  citrulline + NO + 1.5 NADP+ $\rightarrow$L-arginine + 1.5 NADPH + H+ + 2O2 
B)  L-arginine + 1.5 NADPH + H+ + 2O2$\rightarrow$ citrulline + NO + 1.5 NADP+ 
C)  L-arginine + 1.5 NADPH + H+ + 2O2$\rightarrow$ dopamine + NO + 1.5 NADP+ 
D)  L-arginine + 1.5 NADP+ + H+ + 2O2$\rightarrow$ citrulline + NO + 1.5 NADPH

Question 3

A no-protein diet with high doses of L-arginine helps patients with argininosuccinase deficiency because it __________ the concentration of _.

Accepted Answer

A)  increases; fumerate that is metabolized by the citric acid cycle to lower ammonia levels 
B)  increases; ammonia in the diet to keep them regulated 
C)  increases; ornithine that is needed to maintain flux through the urea cycle 
D)  decreases; citrulline to prevent ammonia toxicity 
A)  increases; fumerate that is metabolized by the citric acid cycle to lower ammonia levels 
B)  increases; ammonia in the diet to keep them regulated 
C)  increases; ornithine that is needed to maintain flux through the urea cycle 
D)  decreases; citrulline to prevent ammonia toxicity

Question 4

Alkaptonuria is a disease coming from a deficiency in which pathway?

Accepted Answer

A)  group 1 
B)  group 2 
C)  group 3 
D)  urea 
A)  group 1 
B)  group 2 
C)  group 3 
D)  urea

Question 5

Which of the following is the net reaction of the urea cycle?

Accepted Answer

A)  Urea + Fumerate + 2 ADP + 2Pi + AMP + PPi $\rightarrow$ NH+ + HCO3- + aspartate + 3ATP 
B)  NH+ + HCO3  -  + aspartate + 3ATP $\rightarrow$ urea + fumerate + 2 ADP + 2Pi + AMP + PPi 
C)  NH+ + HCO3  -  + fumerate + 3ATP $\rightarrow$ urea + aspartate + 2 ADP + 2Pi + AMP + PPi 
D)  NH+ + HCO3  -  + aspartate + 2 ADP + 2Pi + AMP + PPi $\rightarrow$ urea + fumerate + 3ATP 
A)  Urea + Fumerate + 2 ADP + 2Pi + AMP + PPi $\rightarrow$ NH+ + HCO3- + aspartate + 3ATP 
B)  NH+ + HCO3  -  + aspartate + 3ATP $\rightarrow$ urea + fumerate + 2 ADP + 2Pi + AMP + PPi 
C)  NH+ + HCO3  -  + fumerate + 3ATP $\rightarrow$ urea + aspartate + 2 ADP + 2Pi + AMP + PPi 
D)  NH+ + HCO3  -  + aspartate + 2 ADP + 2Pi + AMP + PPi $\rightarrow$ urea + fumerate + 3ATP

Question 6

Nitrogen balance is best described as when the daily intake of equals the amount of __________ lost by excretion.

Accepted Answer

A)  ammonia; nitrogen 
B)  nitrogen; nitrogen 
C)  glucose; glucose 
D)  nitrogen; ammonia 
A)  ammonia; nitrogen 
B)  nitrogen; nitrogen 
C)  glucose; glucose 
D)  nitrogen; ammonia

Question 7

Nitrite is oxidized by Nitrobacter bacteria to

Accepted Answer

A)  NO2. 
B)  NO2  -  . 
C)  NO -  . 
D)  NO3  -  . 
A)  NO2. 
B)  NO2  -  . 
C)  NO -  . 
D)  NO3  -  .

Question 8

After food enters the stomach, gastrin triggers the release of and secretion of .

Accepted Answer

A)  gastric juices; pepsinogen 
B)  gastric juices; chyme 
C)  chime; enteropeptidase 
D)  secreton; enteropeptidase 
A)  gastric juices; pepsinogen 
B)  gastric juices; chyme 
C)  chime; enteropeptidase 
D)  secreton; enteropeptidase

Question 9

How are Roundup Ready soybeans resistant to the herbicide?

Accepted Answer

Glyphosate-resistant crops were develope

Question 10

Using the figure below, summarize the synthesis of amino acids from oxaloacetate and pyruvate in E. coli.

Accepted Answer

Nine amino acids are synthesized from ox

Question 11

The urea cycle's function is to the body of an organism.

Accepted Answer

A)  remove excess sugar from 
B)  remove excess water-soluble vitamins from 
C)  remove excess nitrogen from 
D)  add additional nitrogen to 
A)  remove excess sugar from 
B)  remove excess water-soluble vitamins from 
C)  remove excess nitrogen from 
D)  add additional nitrogen to

Question 12

Both Nitrosomonas and Nitrobacter have a key role in nitrification. Nitrosomonas produces __________, whereas Nitrobacter produces .

Accepted Answer

A)  ammonia; nitrite 
B)  nitrite; nitrate 
C)  nitrate; nitrite 
D)  nitrite; ammonia 
A)  ammonia; nitrite 
B)  nitrite; nitrate 
C)  nitrate; nitrite 
D)  nitrite; ammonia

Question 13

Agricultural fertilizers provide the ground with nitrate and nitrite, but only ammonia can be assimilated by plants. What process converts nitrate and nitrite to ammonia?

Accepted Answer

A)  nitrification 
B)  ammonia assimilation 
C)  nitrogen fixation 
D)  nitrogen assimilation 
A)  nitrification 
B)  ammonia assimilation 
C)  nitrogen fixation 
D)  nitrogen assimilation

Question 14

Aminotransferase reactions operate at $\Delta$G $\degree$'  $\approx$ 0. What occurs when there is high substrate availability?

Accepted Answer

A)  Mostly reactants are made. 
B)  Mostly products are made. 
C)  Equal amount of products and reactants are made. 
D)  This reaction is thermodynamically unfavorable. 
A)  Mostly reactants are made. 
B)  Mostly products are made. 
C)  Equal amount of products and reactants are made. 
D)  This reaction is thermodynamically unfavorable.

Question 15

What is the difference between nitrogen fixation and nitrogen assimilation?

Accepted Answer

Nitrogen fixation is carried out by bact

Question 16

Group 2 pathways can be correctly described as pathways that

Accepted Answer

A)  degrade glucogenic amino acids to generate $\alpha$-ketoglutarate. 
B)  convert phenylalanine to tyrosine. 
C)  degrade alanine. 
D)  convert fumerate to oxaloacetate. 
A)  degrade glucogenic amino acids to generate $\alpha$-ketoglutarate. 
B)  convert phenylalanine to tyrosine. 
C)  degrade alanine. 
D)  convert fumerate to oxaloacetate.

Question 17

The shikimate pathway can be defined as the pathway that involves the

Accepted Answer

A)  condensation of phosphoenolpyruvate and erythrose-4-phosphate. 
B)  synthesis of essential amino acids from pyruvate. 
C)  synthesis of essential amino acids from oxaloacetate. 
D)  condensation of oxaloacetate and shikimate. 
A)  condensation of phosphoenolpyruvate and erythrose-4-phosphate. 
B)  synthesis of essential amino acids from pyruvate. 
C)  synthesis of essential amino acids from oxaloacetate. 
D)  condensation of oxaloacetate and shikimate.

Question 18

What molecule signals the endothelial cell to produce NO?

Accepted Answer

A)  dopamine 
B)  phosphate 
C)  acetylcholine 
D)  citrulline 
A)  dopamine 
B)  phosphate 
C)  acetylcholine 
D)  citrulline

Question 19

How can the body easily adjust the relative levels of some amino acids using aminotransferases?

Accepted Answer

A)  Add ATP to the cell to produce more amino acids. 
B)  Use common intermediates to interconvert between amino acids. 
C)  Phosphorylate the amino acids to prevent them from being used. 
D)  Remove NADH from the cell to produce more amino acids. 
A)  Add ATP to the cell to produce more amino acids. 
B)  Use common intermediates to interconvert between amino acids. 
C)  Phosphorylate the amino acids to prevent them from being used. 
D)  Remove NADH from the cell to produce more amino acids.

Question 20

A person who has phenylketonuria must avoid which food additive?

Accepted Answer

A)  protein 
B)  methanol 
C)  aspartame 
D)  phenylalanine 
A)  protein 
B)  methanol 
C)  aspartame 
D)  phenylalanine

Exam 17: Amino Acid Metabolism

How does biological fixation convert nitrogen to ammonia?

Which of the following is the reaction for nitric oxide synthase?

A no-protein diet with high doses of L-arginine helps patients with argininosuccinase deficiency because it __________ the concentration of _.

Alkaptonuria is a disease coming from a deficiency in which pathway?

Which of the following is the net reaction of the urea cycle?

Nitrogen balance is best described as when the daily intake of equals the amount of __________ lost by excretion.

Nitrite is oxidized by Nitrobacter bacteria to

After food enters the stomach, gastrin triggers the release of and secretion of .

How are Roundup Ready soybeans resistant to the herbicide?

Using the figure below, summarize the synthesis of amino acids from oxaloacetate and pyruvate in E. coli.

The urea cycle's function is to the body of an organism.

Both Nitrosomonas and Nitrobacter have a key role in nitrification. Nitrosomonas produces __________, whereas Nitrobacter produces .

Agricultural fertilizers provide the ground with nitrate and nitrite, but only ammonia can be assimilated by plants. What process converts nitrate and nitrite to ammonia?

Aminotransferase reactions operate at Δ\DeltaΔ G °\degree° ' ≈\approx≈ 0. What occurs when there is high substrate availability?

What is the difference between nitrogen fixation and nitrogen assimilation?

Group 2 pathways can be correctly described as pathways that

The shikimate pathway can be defined as the pathway that involves the

What molecule signals the endothelial cell to produce NO?

How can the body easily adjust the relative levels of some amino acids using aminotransferases?

A person who has phenylketonuria must avoid which food additive?

Principles of Biochemistry

Physical Biochemistry: Energy Conversion, Water, and Membranes

Nucleic Acid Structure and Function

Protein Structure

Methods in Protein Biochemistry

Protein Function

Enzyme Mechanisms

Cell Signaling Systems

Glycolysis: a Paradigm of Metabolic Regulation

The Citrate Cycle

Oxidative Phosphorylation

Photosynthesis

Carbohydrate Structure and Function

Carbohydrate Metabolism

Lipid Structure and Function

Lipid Metabolism

Nucleotide Metabolism

Metabolic Integration

DNA Replication, Repair, and Recombination

RNA Synthesis, Processing, and Gene Silencing

Protein Synthesis, Posttranslational Modification, and Transport

Gene Regulation

Filters

Aminotransferase reactions operate at $\Delta$ G $\degree$ ^' $\approx$ 0. What occurs when there is high substrate availability?