You discover a jar of fruit jelly you’ve forgotten for months in the back of your refrigerator. When you open it, you see some white fuzzy growth on the surface. You bring the jar to lab and prepare slides of the culture and determine that only molds, and not bacteria, are present. From this, what can you conclude about fungi and bacteria?
Read DetailsBacteria such as E. coli that can synthesize the amino acids tryptophan, tyrosine, and phenylalanine do so by combining a 3-carbon precursor metabolite and a 4-carbon precursor metabolite to produce a 7-carbon compound that is further modified by a series of steps in a branching pathway leading to their production. The start of the overall pathway, as well as each branchpoint leading to each amino acid, is under feedback inhibition. This means that these amino acids bind to ______.
Read DetailsConsider approaches you’ve studied for controlling bacterial growth. Choose a control method not well covered on this test (e.g., something you studied but haven’t yet had a chance to share!), and describe how it works. If it helps you in writing this, briefly describe (a sentence or two) a scenario involving bacterial contamination or exposure, and then explain how you could use your control method to decontaminate/sanitize/sterilize/etc. microorganisms. What specific impact does this method have on the microorganisms?
Read DetailsSulfa drugs are antibiotics that interfere with folic acid synthesis by acting as a competitive inhibitor on one of the key enzymes, thereby preventing bacteria from making needed folic acid. By contrast, humans acquire folate through the diet and are therefore not affected by sulfa drugs, with the exception of about 3% of people who have an allergic reaction. As a competitive inhibitor, sulfa drugs bind to ______.
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