Together, DNA and RNA store and transfer genetic information. The diagram at the top of this page is a very small segment of the structural formula for one DNA molecule. This assignment must be turned in by the beginning of class tomorrow to receive credit. Calculate the molar concentration for Cl - in blood serum. Eukaryotic cells contain specialized structures surrounded by membranes.
Biologists agree that all living things are made of cells.
The only other elements that are significant constituents of biological molecules are P , and S . Living things use traces of Na , Mg , Cl , K , Ca , and Fe . Escherichia coli or, as it is commonly known, E. coli . Within the cell, E. coli contains from one to four identical molecules of DNA and 15,000-30,000 ribosomes. Immediately outside the plasma membrane is a cell wall about 10 nm thick, and projecting from the cell are flagella and pili.