Draw a hypothetical metabolic pathway in Neurospora crassa compos...

Question

Draw a hypothetical metabolic pathway in Neurospora crassa composed of five substrates, five enzymes, and a product called nirvana. Number the substrates 1–5, and label the enzymes A–E, in order. (For instance, enzyme A catalyzes the reaction between substrates 1 and 2.) (b) Suppose a mutant strain can survive if substrate 5 is added to the growth medium, but it cannot grow if substrates 1, 2, 3, or 4 are added. Which enzyme in the pathway is affected in this mutant?

Accepted Answer

Hello everyone today. We have a very long problem. However, we're going to try to simplify in order to be able to solve them more effectively. So we have that we have certain Eurosport a cell that are able to grow in a minimal medium. Then we took these cells and we created mutants from them which are called Eurosport mutants using UV exposure. Now we found that these mutants are able to grow in the complete medium as we see down here. However, they cannot grow in the minimal medium. So how can we explain this phenomenon? And so let's go over answer choices so that we can solve this problem. First of all we have that the medium got contaminated. Now there is no information in the entire problem that relates to the medium being contaminated by outside sources. So we cannot assume that it was contaminated and we will cancel this out as it is not a possible answer choice. Then we have that the mutants have weaker resistance and immunity as we can see here where the mutants are actually able to survive in certain mediums. They're just not able to survive in others. So it is not that their resistance and immunity was compromised but that the resistance and immunity or just their metabolism in certain mediums was compromised. So will cancel this out as well. And it is as it is partially incorrect. Then we have the mutants cannot produce a viable Again, we have that they are able to reproduce or just live in the complete medium. So this is not a correct answer choice and we will cancel it out. This all leaves us with the metabolic pathways that enable them to survive in a minimal medium have been broken. So I want you to think about this so they're able to survive in the complete medium. So they are viable colonies. However, they are not able to survive in the minimal medium. The only way that this can happen is that the metabolic pathways that allow it to survive in the minimal medium by using sugar, salt and biotin have been compromised so they cannot use these anymore and so they are unable to survive here. This is going to be the final answer to our question, and we will highlight it. Thank you very much for sticking around until the end of this video, and I hope this helped you.

Watch next