The steps of the biosynthetic pathway that are associated with each type of mutation from the given data. Given: Two mutant strains of Neurospora ( Leu- 1 and Leu- 2), the wild-type and the fused-type were supplied with different nutrient media and their growth was recorded in Table 1. The presence of growth is indicated by the positive sign (+) and the absence of growth is indicated by the negative sign (−). Table 1: The results of the growth of different strains of Neurospora in different media. Types of strains used in the experiment The growth of different strains of Neurospora in different media Minimal medium Minimal medium+2-isopropylmalate Minimal medium+leucine Minimal medium+3-isopropylmalate Minimal medium+α-ketoisocaproate Wild-type (haploid) + + + + + Leu- 1 (haploid) − − + − + Leu -2 (haploid) − − + + + Fused cells (diploid): Leu -1, Leu -2 − + + + + The following reaction shows the steps involved in the synthesis of leucine in Neurospora (Figure 1). Figure 1: Introduction: The leucine is an essential amino acid that is basic in nature because of the presence of an amino group. Some organisms like Neurospora are able to catalyze the synthesis of leucine in their cells. The Neurospora is a haploid fungus that is used as a model organism because it is able to grow quickly on the minimal media in the laboratory.

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Answer 1

Question

Chapter 14, Problem 1Q

Summary Introduction

To analyze:

The steps of the biosynthetic pathway that are associated with each type of mutation from the given data.

Given:

Two mutant strains of Neurospora (Leu-1 and Leu-2), the wild-type and the fused-type were supplied with different nutrient media and their growth was recorded in Table 1. The presence of growth is indicated by the positive sign (+) and the absence of growth is indicated by the negative sign (−).

Table 1: The results of the growth of different strains of Neurospora in different media.

Types of strains used in the experiment The growth of different strains of Neurospora in different media

Minimal medium Minimal medium+2-isopropylmalate Minimal medium+leucine Minimal medium+3-isopropylmalate Minimal medium+α-ketoisocaproate

Wild-type (haploid) + + + + +

Leu-1 (haploid) − − + − +

Leu-2 (haploid) − − + + +

Fused cells (diploid): Leu-1, Leu-2 − + + + +

The following reaction shows the steps involved in the synthesis of leucine in Neurospora (Figure 1).

Figure 1:

Introduction:

The leucine is an essential amino acid that is basic in nature because of the presence of an amino group. Some organisms like Neurospora are able to catalyze the synthesis of leucine in their cells. The Neurospora is a haploid fungus that is used as a model organism because it is able to grow quickly on the minimal media in the laboratory.

Expert Solution & Answer

Explanation of Solution

Neurospora is able to synthesize leucine in their cells and hence, are able to grow on a minimal medium (a medium that does not contain additional amino acids). The mutant strains of Neurospora lack the precursors that are required to perform the metabolic steps for the leucine synthesis. The two important mutant strains of Neurospora are Leu-1 and Leu-2.

From the given table and diagram, it is observed that Leu-1 strain contains a mutation in the protein that is required for the synthesis of α-ketoisocaproate. This is because this strain is unable to grow in the minimal medium supplied with 3-isopropylmalate and 2- isopropylmalate. Here the step C, i.e., the conversion of 3-isopropylmalate into α-ketoisocaproate, does not occur due to mutation, which prevents the further synthesis of leucine.

Leu-2 contains a mutant protein that is unable to synthesize the 3-isopropylmalate. This is because this strain is unable to grow on the minimal media, supplied with 2-isopropylmalate. The mutation in enzyme involved in step B that prevents the synthesis of 3-isopropylmalate from 2-isopropylmalate, thus, the final product leucine.

Conclusion

Thus, it can be concluded from the given data that the Leu-1 strain has a mutant protein that prevents the catalysis of step C and Leu-2 strain has a mutant protein that is unable to catalyze the step B of the given biosynthetic pathway.

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Students have asked these similar questions

Biochemistry: Site-directed mutagenesis, in which individual amino acid residues are replaced with others, is a powerful method to study enzyme mechanisms. In experiments with particular enzyme, various lysine residues were replaced with aspartate, yielding the results summarized in the table below: Enzyme Form: Enzyme Activity (U/mg) Native enzyme: 1,000 U/mg Recombinant Lys 21 to Asp 21: 970 U/mg Recombinant Lys 86 to Asp 86: 100 U/mg Recombinant Lys 101 to Asp 101: 970 U/mg a. What might be inferred about the role of Lys 21, 86, and 101 in the catalytic mechanism of this enzyme? b. Discuss where within the enzyme one might find Lys 21 and 101. Are these residues likely to be evolutionary conserved in this enzyme? Explain c. Is Lys position 86 likely to be evolutionary conserved? Explain

For each of the five short mRNA nucleotide sequences given in the table below: 3. Translate the original sequence (for these short sequences start translation at the first nucleotide) 4. Identify (and highlight or underline) the one nucleotide difference between the original (left) and altered (right) sequences 5. For each altered nucleotide sequence give the type of mutation (effect at the DNA/nucleotide level; see #1 above) 6. Translate each changed sequence. Does the mutation result in a change in the amino acid sequence? If so, what is the effect of the mutation on protein structure (amino acid sequence; see #2 above)

Which of the following types of enzymes is primarily responsible for setting up the genetic code? 1.) Kinases 2.) DNA ligase 3.) DNA gyrase 4.) peptidyl transferase 5.) aminoacyl tRNA synthetases (charging enzymes)

Answer 2

Question

Chapter 14, Problem 1Q

Summary Introduction

To analyze:

The steps of the biosynthetic pathway that are associated with each type of mutation from the given data.

Given:

Two mutant strains of Neurospora (Leu-1 and Leu-2), the wild-type and the fused-type were supplied with different nutrient media and their growth was recorded in Table 1. The presence of growth is indicated by the positive sign (+) and the absence of growth is indicated by the negative sign (−).

Table 1: The results of the growth of different strains of Neurospora in different media.

Types of strains used in the experiment The growth of different strains of Neurospora in different media

Minimal medium Minimal medium+2-isopropylmalate Minimal medium+leucine Minimal medium+3-isopropylmalate Minimal medium+α-ketoisocaproate

Wild-type (haploid) + + + + +

Leu-1 (haploid) − − + − +

Leu-2 (haploid) − − + + +

Fused cells (diploid): Leu-1, Leu-2 − + + + +

The following reaction shows the steps involved in the synthesis of leucine in Neurospora (Figure 1).

Figure 1:

Introduction:

The leucine is an essential amino acid that is basic in nature because of the presence of an amino group. Some organisms like Neurospora are able to catalyze the synthesis of leucine in their cells. The Neurospora is a haploid fungus that is used as a model organism because it is able to grow quickly on the minimal media in the laboratory.

Expert Solution & Answer

Explanation of Solution

Neurospora is able to synthesize leucine in their cells and hence, are able to grow on a minimal medium (a medium that does not contain additional amino acids). The mutant strains of Neurospora lack the precursors that are required to perform the metabolic steps for the leucine synthesis. The two important mutant strains of Neurospora are Leu-1 and Leu-2.

From the given table and diagram, it is observed that Leu-1 strain contains a mutation in the protein that is required for the synthesis of α-ketoisocaproate. This is because this strain is unable to grow in the minimal medium supplied with 3-isopropylmalate and 2- isopropylmalate. Here the step C, i.e., the conversion of 3-isopropylmalate into α-ketoisocaproate, does not occur due to mutation, which prevents the further synthesis of leucine.

Leu-2 contains a mutant protein that is unable to synthesize the 3-isopropylmalate. This is because this strain is unable to grow on the minimal media, supplied with 2-isopropylmalate. The mutation in enzyme involved in step B that prevents the synthesis of 3-isopropylmalate from 2-isopropylmalate, thus, the final product leucine.

Conclusion

Thus, it can be concluded from the given data that the Leu-1 strain has a mutant protein that prevents the catalysis of step C and Leu-2 strain has a mutant protein that is unable to catalyze the step B of the given biosynthetic pathway.

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Answer 3

Question

Chapter 14, Problem 1Q

Summary Introduction

To analyze:

The steps of the biosynthetic pathway that are associated with each type of mutation from the given data.

Given:

Two mutant strains of Neurospora (Leu-1 and Leu-2), the wild-type and the fused-type were supplied with different nutrient media and their growth was recorded in Table 1. The presence of growth is indicated by the positive sign (+) and the absence of growth is indicated by the negative sign (−).

Table 1: The results of the growth of different strains of Neurospora in different media.

Types of strains used in the experiment The growth of different strains of Neurospora in different media

Minimal medium Minimal medium+2-isopropylmalate Minimal medium+leucine Minimal medium+3-isopropylmalate Minimal medium+α-ketoisocaproate

Wild-type (haploid) + + + + +

Leu-1 (haploid) − − + − +

Leu-2 (haploid) − − + + +

Fused cells (diploid): Leu-1, Leu-2 − + + + +

The following reaction shows the steps involved in the synthesis of leucine in Neurospora (Figure 1).

Figure 1:

Introduction:

The leucine is an essential amino acid that is basic in nature because of the presence of an amino group. Some organisms like Neurospora are able to catalyze the synthesis of leucine in their cells. The Neurospora is a haploid fungus that is used as a model organism because it is able to grow quickly on the minimal media in the laboratory.

Expert Solution & Answer

Explanation of Solution

Neurospora is able to synthesize leucine in their cells and hence, are able to grow on a minimal medium (a medium that does not contain additional amino acids). The mutant strains of Neurospora lack the precursors that are required to perform the metabolic steps for the leucine synthesis. The two important mutant strains of Neurospora are Leu-1 and Leu-2.

From the given table and diagram, it is observed that Leu-1 strain contains a mutation in the protein that is required for the synthesis of α-ketoisocaproate. This is because this strain is unable to grow in the minimal medium supplied with 3-isopropylmalate and 2- isopropylmalate. Here the step C, i.e., the conversion of 3-isopropylmalate into α-ketoisocaproate, does not occur due to mutation, which prevents the further synthesis of leucine.

Leu-2 contains a mutant protein that is unable to synthesize the 3-isopropylmalate. This is because this strain is unable to grow on the minimal media, supplied with 2-isopropylmalate. The mutation in enzyme involved in step B that prevents the synthesis of 3-isopropylmalate from 2-isopropylmalate, thus, the final product leucine.

Conclusion

Thus, it can be concluded from the given data that the Leu-1 strain has a mutant protein that prevents the catalysis of step C and Leu-2 strain has a mutant protein that is unable to catalyze the step B of the given biosynthetic pathway.

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Answer 4

Question

Chapter 14, Problem 1Q

Summary Introduction

To analyze:

The steps of the biosynthetic pathway that are associated with each type of mutation from the given data.

Given:

Two mutant strains of Neurospora (Leu-1 and Leu-2), the wild-type and the fused-type were supplied with different nutrient media and their growth was recorded in Table 1. The presence of growth is indicated by the positive sign (+) and the absence of growth is indicated by the negative sign (−).

Table 1: The results of the growth of different strains of Neurospora in different media.

Types of strains used in the experiment The growth of different strains of Neurospora in different media

Minimal medium Minimal medium+2-isopropylmalate Minimal medium+leucine Minimal medium+3-isopropylmalate Minimal medium+α-ketoisocaproate

Wild-type (haploid) + + + + +

Leu-1 (haploid) − − + − +

Leu-2 (haploid) − − + + +

Fused cells (diploid): Leu-1, Leu-2 − + + + +

The following reaction shows the steps involved in the synthesis of leucine in Neurospora (Figure 1).

Figure 1:

Introduction:

The leucine is an essential amino acid that is basic in nature because of the presence of an amino group. Some organisms like Neurospora are able to catalyze the synthesis of leucine in their cells. The Neurospora is a haploid fungus that is used as a model organism because it is able to grow quickly on the minimal media in the laboratory.

Expert Solution & Answer

Explanation of Solution

Neurospora is able to synthesize leucine in their cells and hence, are able to grow on a minimal medium (a medium that does not contain additional amino acids). The mutant strains of Neurospora lack the precursors that are required to perform the metabolic steps for the leucine synthesis. The two important mutant strains of Neurospora are Leu-1 and Leu-2.

From the given table and diagram, it is observed that Leu-1 strain contains a mutation in the protein that is required for the synthesis of α-ketoisocaproate. This is because this strain is unable to grow in the minimal medium supplied with 3-isopropylmalate and 2- isopropylmalate. Here the step C, i.e., the conversion of 3-isopropylmalate into α-ketoisocaproate, does not occur due to mutation, which prevents the further synthesis of leucine.

Leu-2 contains a mutant protein that is unable to synthesize the 3-isopropylmalate. This is because this strain is unable to grow on the minimal media, supplied with 2-isopropylmalate. The mutation in enzyme involved in step B that prevents the synthesis of 3-isopropylmalate from 2-isopropylmalate, thus, the final product leucine.

Conclusion

Thus, it can be concluded from the given data that the Leu-1 strain has a mutant protein that prevents the catalysis of step C and Leu-2 strain has a mutant protein that is unable to catalyze the step B of the given biosynthetic pathway.

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Answer 5

Chapter 14, Problem 1Q

Summary Introduction

To analyze:

The steps of the biosynthetic pathway that are associated with each type of mutation from the given data.

Given:

Two mutant strains of Neurospora (Leu-1 and Leu-2), the wild-type and the fused-type were supplied with different nutrient media and their growth was recorded in Table 1. The presence of growth is indicated by the positive sign (+) and the absence of growth is indicated by the negative sign (−).

Table 1: The results of the growth of different strains of Neurospora in different media.

Types of strains used in the experiment The growth of different strains of Neurospora in different media

Minimal medium Minimal medium+2-isopropylmalate Minimal medium+leucine Minimal medium+3-isopropylmalate Minimal medium+α-ketoisocaproate

Wild-type (haploid) + + + + +

Leu-1 (haploid) − − + − +

Leu-2 (haploid) − − + + +

Fused cells (diploid): Leu-1, Leu-2 − + + + +

The following reaction shows the steps involved in the synthesis of leucine in Neurospora (Figure 1).

Figure 1:

Introduction:

The leucine is an essential amino acid that is basic in nature because of the presence of an amino group. Some organisms like Neurospora are able to catalyze the synthesis of leucine in their cells. The Neurospora is a haploid fungus that is used as a model organism because it is able to grow quickly on the minimal media in the laboratory.

Expert Solution & Answer

Explanation of Solution

Neurospora is able to synthesize leucine in their cells and hence, are able to grow on a minimal medium (a medium that does not contain additional amino acids). The mutant strains of Neurospora lack the precursors that are required to perform the metabolic steps for the leucine synthesis. The two important mutant strains of Neurospora are Leu-1 and Leu-2.

From the given table and diagram, it is observed that Leu-1 strain contains a mutation in the protein that is required for the synthesis of α-ketoisocaproate. This is because this strain is unable to grow in the minimal medium supplied with 3-isopropylmalate and 2- isopropylmalate. Here the step C, i.e., the conversion of 3-isopropylmalate into α-ketoisocaproate, does not occur due to mutation, which prevents the further synthesis of leucine.

Leu-2 contains a mutant protein that is unable to synthesize the 3-isopropylmalate. This is because this strain is unable to grow on the minimal media, supplied with 2-isopropylmalate. The mutation in enzyme involved in step B that prevents the synthesis of 3-isopropylmalate from 2-isopropylmalate, thus, the final product leucine.

Conclusion

Thus, it can be concluded from the given data that the Leu-1 strain has a mutant protein that prevents the catalysis of step C and Leu-2 strain has a mutant protein that is unable to catalyze the step B of the given biosynthetic pathway.

Answer 6

Chapter 14, Problem 1Q

Summary Introduction

To analyze:

The steps of the biosynthetic pathway that are associated with each type of mutation from the given data.

Given:

Two mutant strains of Neurospora (Leu-1 and Leu-2), the wild-type and the fused-type were supplied with different nutrient media and their growth was recorded in Table 1. The presence of growth is indicated by the positive sign (+) and the absence of growth is indicated by the negative sign (−).

Table 1: The results of the growth of different strains of Neurospora in different media.

Types of strains used in the experiment The growth of different strains of Neurospora in different media

Minimal medium Minimal medium+2-isopropylmalate Minimal medium+leucine Minimal medium+3-isopropylmalate Minimal medium+α-ketoisocaproate

Wild-type (haploid) + + + + +

Leu-1 (haploid) − − + − +

Leu-2 (haploid) − − + + +

Fused cells (diploid): Leu-1, Leu-2 − + + + +

The following reaction shows the steps involved in the synthesis of leucine in Neurospora (Figure 1).

Figure 1:

Introduction:

The leucine is an essential amino acid that is basic in nature because of the presence of an amino group. Some organisms like Neurospora are able to catalyze the synthesis of leucine in their cells. The Neurospora is a haploid fungus that is used as a model organism because it is able to grow quickly on the minimal media in the laboratory.

Expert Solution & Answer

Explanation of Solution

Neurospora is able to synthesize leucine in their cells and hence, are able to grow on a minimal medium (a medium that does not contain additional amino acids). The mutant strains of Neurospora lack the precursors that are required to perform the metabolic steps for the leucine synthesis. The two important mutant strains of Neurospora are Leu-1 and Leu-2.

From the given table and diagram, it is observed that Leu-1 strain contains a mutation in the protein that is required for the synthesis of α-ketoisocaproate. This is because this strain is unable to grow in the minimal medium supplied with 3-isopropylmalate and 2- isopropylmalate. Here the step C, i.e., the conversion of 3-isopropylmalate into α-ketoisocaproate, does not occur due to mutation, which prevents the further synthesis of leucine.

Leu-2 contains a mutant protein that is unable to synthesize the 3-isopropylmalate. This is because this strain is unable to grow on the minimal media, supplied with 2-isopropylmalate. The mutation in enzyme involved in step B that prevents the synthesis of 3-isopropylmalate from 2-isopropylmalate, thus, the final product leucine.

Conclusion

Thus, it can be concluded from the given data that the Leu-1 strain has a mutant protein that prevents the catalysis of step C and Leu-2 strain has a mutant protein that is unable to catalyze the step B of the given biosynthetic pathway.

Answer 7

Chapter 14, Problem 1Q

Summary Introduction

To analyze:

The steps of the biosynthetic pathway that are associated with each type of mutation from the given data.

Given:

Two mutant strains of Neurospora (Leu-1 and Leu-2), the wild-type and the fused-type were supplied with different nutrient media and their growth was recorded in Table 1. The presence of growth is indicated by the positive sign (+) and the absence of growth is indicated by the negative sign (−).

Table 1: The results of the growth of different strains of Neurospora in different media.

Types of strains used in the experiment The growth of different strains of Neurospora in different media

Minimal medium Minimal medium+2-isopropylmalate Minimal medium+leucine Minimal medium+3-isopropylmalate Minimal medium+α-ketoisocaproate

Wild-type (haploid) + + + + +

Leu-1 (haploid) − − + − +

Leu-2 (haploid) − − + + +

Fused cells (diploid): Leu-1, Leu-2 − + + + +

The following reaction shows the steps involved in the synthesis of leucine in Neurospora (Figure 1).

Figure 1:

Introduction:

The leucine is an essential amino acid that is basic in nature because of the presence of an amino group. Some organisms like Neurospora are able to catalyze the synthesis of leucine in their cells. The Neurospora is a haploid fungus that is used as a model organism because it is able to grow quickly on the minimal media in the laboratory.

Answer 8

Expert Solution & Answer

Explanation of Solution

Neurospora is able to synthesize leucine in their cells and hence, are able to grow on a minimal medium (a medium that does not contain additional amino acids). The mutant strains of Neurospora lack the precursors that are required to perform the metabolic steps for the leucine synthesis. The two important mutant strains of Neurospora are Leu-1 and Leu-2.

From the given table and diagram, it is observed that Leu-1 strain contains a mutation in the protein that is required for the synthesis of α-ketoisocaproate. This is because this strain is unable to grow in the minimal medium supplied with 3-isopropylmalate and 2- isopropylmalate. Here the step C, i.e., the conversion of 3-isopropylmalate into α-ketoisocaproate, does not occur due to mutation, which prevents the further synthesis of leucine.

Leu-2 contains a mutant protein that is unable to synthesize the 3-isopropylmalate. This is because this strain is unable to grow on the minimal media, supplied with 2-isopropylmalate. The mutation in enzyme involved in step B that prevents the synthesis of 3-isopropylmalate from 2-isopropylmalate, thus, the final product leucine.

Answer 9

Expert Solution & Answer

Answer 10

Expert Solution & Answer

Answer 11

Conclusion

Thus, it can be concluded from the given data that the Leu-1 strain has a mutant protein that prevents the catalysis of step C and Leu-2 strain has a mutant protein that is unable to catalyze the step B of the given biosynthetic pathway.

Answer 12

Ch. 14.1 - Prob. 1R Ch. 14.1 - Prob. 2R Ch. 14.1 - Prob. 3R Ch. 14.2 - Prob. 1R Ch. 14.2 - Prob. 2R Ch. 14.3 - Prob. 1R Ch. 14.3 - Prob. 2R Ch. 14.3 - Prob. 3R Ch. 14.4 - Prob. 1R Ch. 14.4 - Prob. 2R

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Chapter 14 Solutions

Types of strains used in the experiment	The growth of different strains of Neurospora in different media
Types of strains used in the experiment	Minimal medium	Minimal medium+2-isopropylmalate	Minimal medium+leucine	Minimal medium+3-isopropylmalate	Minimal medium+α-ketoisocaproate
Wild-type (haploid)	+	+	+	+	+
Leu-1 (haploid)	−	−	+	−	+
Leu-2 (haploid)	−	−	+	+	+
Fused cells (diploid): Leu-1, Leu-2	−	+	+	+	+