The special strain of Neurospora that makes citrulline but not arginine and the mutant or missing gene in the strain. Introduction. All the enzymes in the body that are crucial for the biochemical reactions are proteins. The proteins are made of amino acids. The amino acids are of 20 types that combine in a varied manner to form proteins. The amino acids join together by peptide bonds. Proteins act as major substrates and reactants for the metabolic pathways.

Question

Want to see the full answer?

Answer 1

Question

Chapter 1, Problem 3P

Summary Introduction

To determine: The special strain of Neurospora that makes citrulline but not arginine and the mutant or missing gene in the strain.

Introduction. All the enzymes in the body that are crucial for the biochemical reactions are proteins. The proteins are made of amino acids. The amino acids are of 20 types that combine in a varied manner to form proteins. The amino acids join together by peptide bonds. Proteins act as major substrates and reactants for the metabolic pathways.

Expert Solution & Answer

Want to see the full answer?

Check out a sample textbook solution

See solution

Students have asked these similar questions

Neurospora crassa can synthesize the amino acid arginine from a precursor as follows: precursor ornithine citrulline arginine George Beadle and Edward Tatum identified various mutants (arg mutants) unable to synthesize arginine from this precursor. One such class (Class I) could synthesize arginine if either ornithine or citrulline was supplied. A second mutant class (Class II) could synthesize arginine if citrulline was added, but not if ornithine was added. A third class (Class III) could not synthesize arginine from either ornithine or citrulline. Which class or classes of arg mutants will grow on complete media?

Draw a diagram/figure to explain the conjugation process (e.g. use PowerPoint or draw one by hand and include a photo of it). You should include in the diagram the F- recipient, Hfr Donor and the transconjugant/recombinant recipient. Make sure to include the genes encoding for Leucine, Threonine, Thiamine and Streptomycin resistance in your diagram. How does an Hfr strain of coli transfers chromosomal DNA to an F- strain? What determines how much of the chromosomal DNA is transferred?

b. Neurospora has an arginine amino acid synthesis pathway shown below: ornithine citrulline arginine NH H2N H2N OH H2N HO HO NH2 NH2 ÑH2 Enzyme A Enzyme B Enzyme C ↑ ↑ Gene A Gene B Gene C Suppose I have a neurospora strain that has a mutation such that it will not grow unless I supplement the media (food) with arginine (but not with citrulline or ornithine). What gene is mutated? Explain your reasoning. C. Suppose I take the strain above that only grows with arginine supplements and cross it to a different mutant Neurospora strain that grows with arginine and citrulline supplements but not ornithine supplements. Assming genes A, B and C are unlinked and there is only one mutation per strain: i) What percentage of the progeny will grow on ornithine? ii) What percentage on citrulline? iii) What percentage on arginine? Show your work for i), ii) and iii). |