module 1-Ch-v1.ppt

Special Practice Problem (not in text)....suppose you took one cell of E. coli (Table 4.1) which weighs has a dry weight of 2.8 x 10-13 grams, or a whole cell weight (wet weight) of 2.5 x 10-12 grams...when actively growing. Now, place that ONE cell into a very large flask complete with all the nutrients required to keep this cell and its progeny in active growth...with a generation time of 22 minutes. What will be the net weight of the bacteria in this culture after 48 hours of logarithmic growth from one cell? Is this net weight bigger that is something rather large? ? ANSWER to the Growth Question Above: 5.7 x 1027 grams or 5.7 x 1024 kg. Be careful, if you round out some numbers and are dealing with logs, you wont get exactly 5.7...but that is OK as long as it is times 1027 grams! What weighs that much = the Planet Earth! The total weight of our planet is 6 x 1024 kg. Thus, clearly we cant do this experiment, there is no flask large enough!! But, this mental exercise shows the impressive growth potential of bacteria: what they do best is grow fast. No other form of life can grow as fast as bacteria, thus given nutrients, bacteria are the first to exploit any environment. ? Sources are: Food, water, objects, people, air, etc. ? Special Practice Problem (not in text)....suppose you took one cell of E. coli (Table 4.1) which weighs has a dry weight of 2.8 x 10-13 grams, or a whole cell weight (wet weight) of 2.5 x 10-12 grams...when actively growing. Now, place that ONE cell into a very large flask complete with all the nutrients required to keep this cell and its progeny in active growth...with a generation time of 22 minutes. What will be the net weight of the bacteria in this culture after 48 hours of logarithmic growth from one cell? Is this net weight bigger that is something rather large? ? ANSWER to the Growth Question Above: 5.7 x 1027 grams or 5.7 x 1024 kg. Be careful, if you round out some numbers and are dealing with logs, you wont get exactl