Suppose that E. coli synthesizes DNA at a rate of 100,000 nucleotides per minute and takes 40 minutes to replicate its chromosome. (a) How many base pairs are present in the entire E. coli chromosome? (b) What is the physical length of the chromosome in its helical configuration—that is, what is the circumference of the chromosome if it were opened into a circle?

Hello everyone here we have a question asking us what is the number of base pairs? And e coli if its D. N. A. Is 1.7 millimeters long. So first we need the distance between two base pairs which is 0. nanometers. And we want to change that to meters. So if we remember correctly our factor for changing nanometers, two m is one times 10 to the negative ninth and that's how many meters are in a single nanometer. So we're going to put one times 10 to the negative nine m over one nanometer. And our nanometers are going to cancel out here and that is going to equal 0.34 Times 10 to the -9. So now we're going to take the length of DNA divided by the distance between our base pairs. So we're going to take 1.7 Divided by 0.34 Times 10 to the negative night. And this equals five times 10 to the 6th base pairs. So our answer here is C5 times 10 to the 6th. Bass players. Thank you for watching. Bye.