4. You are examining a microorganism that is growing under anoxic conditions with no available terminal electron acceptors for NADH. Describe how this organism will go about catabolizing glucose under this condition.

1. You set up two cultures with an equal amounts of Escherichia coli. You label one culture "A" and the other "B." Each culture is given 100mL of tryptic soy nutrient broth. You then take culture A and incubate it in the absence of oxygen and take culture B and incubate it in the presence of oxygen for one week. If E. coli is able to use both aerobic and anaerobic metabolism, the how would we classify it? Is it an obligate aerobe, obligate anaerobe, or a facultative anaerobe? Based on that information, which flask, A or B, would have more cells at the end of the week? Fully explain your answer.

Energy conservation in microorganisms can be highly diverse. Technically, any pair of electron donor (donates electrons and is oxidized) and electron acceptor (accepts electrons and is reduced) that forms a redox reaction with positive reduction potential can support microbial growth, although many of them have not been observed. Calculate how many moles of ATP can theoretically be generated from 1 mole of sulfur (So/SO4-) as the electron donor and nitrate as the electron acceptor (NO3-/N2).

2. Order the following TCA cycle metabolites in the order they appear in the cycle. Not all answers will be used. 1. 2. 3. 4. choices: pyruvate, alpha ketogluterate, glucose-6-phosphate, lactate, aconitase, isocitrate, oxaloacetate, fumarate.