Question

E.coli is a rod shaped bacteria about 2 micrometre long and 1 micrometre in diameter.The average density of a cell is 1.28g/ml. Approximately 13.5% of the wet weight of E.coli is soluble protein .Estimate the number of molecules of a particular enzyme per cell if the enzyme has a molecular weight of 100,000 and represents 0.1% of the total soluble protein.

Answer 1

The many rods and sausage shapes here are individual cells of the bacterium Escherichia coli, or E. coli for short. The view in this slide is 9.5 micrometers across, so each E. coli bacterium is about 1–2 micrometers long and about 0.25 micrometer in diameter.