
Concept explainers
What would happen if a microorganism that depended on the glyoxylate cycle no longer produced the enzyme isocitrate lyase? Could this defect be corrected by nutrients in the media? If so, which nutrients?

The glyoxylate cycle is a pathway in which the acetyl-CoA is converted to succinate, for the synthesis of carbohydrates. This cycle is similar to the tricarboxylic (TCA) cycle, but certain steps in the TCA cycle are bypassed. Initial and final steps are similar for both cycles. The final result of the glyoxylate cycle is glucose production from fatty acids.
Explanation of Solution
Isocitrate lyase is an enzyme involved in the glyoxylate cycle. Isocitrate lyase (ICL) enzyme cleaves the isocitrate into glyoxylate and succinate. The micro-organisms that undergo glyoxylate cycle use isocitrate lyase and malate synthase in order to synthesize glucose, and also its metabolic intermediates. When the ICL gene was deleted, then the microorganism cannot survive under conditions where the glyoxylate cycle was important, as they cannot synthesize glucose. This is called gene knockout, where the genes of organisms are made inoperative.
This can be corrected by providing succinate and glyoxylate in the media and this is known as nutritional complementation of the knockout, where the absence of this gene is compensated by providing the products produced by the gene in the media. The presence of succinate and glyoxylate in the media can bypass the requirement of this enzyme (ICL). In this case, glucose can also be provided in the media. So, the micro-organisms that cannot undergo the glyoxylate cycle and synthesize glucose, can utilize the glucose available in the media.
Want to see more full solutions like this?
Chapter 12 Solutions
Prescott's Microbiology
- Explain how the hormones of the glands listed below travel around the body to target organs and tissues : Pituitary gland Hypothalamus Thyroid Parathyroid Adrenal Pineal Pancreas(islets of langerhans) Gonads (testes and ovaries) Placentaarrow_forwardWhat are the functions of the hormones produced in the glands listed below: Pituitary gland Hypothalamus Thyroid Parathyroid Adrenal Pineal Pancreas(islets of langerhans) Gonads (testes and ovaries) Placentaarrow_forwardDescribe the hormones produced in the glands listed below: Pituitary gland Hypothalamus Thyroid Parathyroid Adrenal Pineal Pancreas(islets of langerhans) Gonads (testes and ovaries) Placentaarrow_forward
- Please help me calculate drug dosage from the following information: Patient weight: 35 pounds, so 15.9 kilograms (got this by dividing 35 pounds by 2.2 kilograms) Drug dose: 0.05mg/kg Drug concentration: 2mg/mLarrow_forwardA 25-year-old woman presents to the emergency department with a 2-day history of fever, chills, severe headache, and confusion. She recently returned from a trip to sub-Saharan Africa, where she did not take malaria prophylaxis. On examination, she is febrile (39.8°C/103.6°F) and hypotensive. Laboratory studies reveal hemoglobin of 8.0 g/dL, platelet count of 50,000/μL, and evidence of hemoglobinuria. A peripheral blood smear shows ring forms and banana-shaped gametocytes. Which of the following Plasmodium species is most likely responsible for her severe symptoms? A. Plasmodium vivax B. Plasmodium ovale C. Plasmodium malariae D. Plasmodium falciparumarrow_forwardStandard Concentration (caffeine) mg/L Absorbance Reading 10 0.322 20 0.697 40 1.535 60 2.520 80 3.100arrow_forward
- please draw in the answers, thank youarrow_forwarda. On this first grid, assume that the DNA and RNA templates are read left to right. DNA DNA mRNA codon tRNA anticodon polypeptide _strand strand C с A T G A U G C A TRP b. Now do this AGAIN assuming that the DNA and RNA templates are read right to left. DNA DNA strand strand C mRNA codon tRNA anticodon polypeptide 0 A T G A U G с A TRParrow_forwardplease answer all question below with the following answer choice, thank you!arrow_forward
- Surgical Tech For Surgical Tech Pos CareHealth & NutritionISBN:9781337648868Author:AssociationPublisher:Cengage
- BiochemistryBiochemistryISBN:9781305577206Author:Reginald H. Garrett, Charles M. GrishamPublisher:Cengage LearningConcepts of BiologyBiologyISBN:9781938168116Author:Samantha Fowler, Rebecca Roush, James WisePublisher:OpenStax College


