As resources become scarce because of population growth, the growth

A50-ml crude extract of skeletal muscle contains 32 mg of protein per ml. ten μl of the extract catalyzes a reaction at a rate of 0.14 μmol product formed per minute. the extract was fractionated by ammonium sulfate precipitation, and the fraction precipitating between 20% and 40% saturation was redissolved in10 ml. this solution contains 50 mg/ml protein. ten μl of this purifi ed fraction catalyzes the reaction at a rate of 0.65 μmol/min. (a) what is the degree of purifi cation (fold purifi cation)? (b) what is the percent yield of the enzyme recovered in the purifi ed fraction?

Which statement best describes lactic acid fermentation? a. lactic acid fermentation is the first step of cellular respiration. o b. lactic acid fermentation is the final step of cellular respiration. re to berate c. in the absence of oxygen, cells release atp by breaking down lactose into glucose. e der lade res o d. in the absence of oxygen, cells release atp by breaking down glucose into lactate. ar

Keeping in mind the life cycle of bacteriophages, consider the following problem: during the reproductive cycle of a temperate bacteriophage, the viral dna inserts into the bacterial chromosome where the resultant prophage behaves much like a trojan horse. it can remain quiescent, or it can become lytic and initiate a burst of progeny viruses. several operons maintain the prophage state by interacting with a repressor that keeps the lytic cycle in check. insults (ultraviolet light, for example) to the bacterial cell lead to a partial breakdown of the repressor, which in turn causes the production of enzymes involved in the lytic cycle. as stated in this simple form, would you consider this system of regulation to be operating under positive or negative control?