The cell membrane functions as a selective barrier. We call these kind of membranes as differentially permeable or semi permeable membrane. It can decide what substances can pass in and out. Therefore it can surround the cytoplasm (which is the inside of a cell) to separate the cell's content from the surroundings.
Both cells have ribosomes, cytoplams and DNA, but the ribosomes are the structures that can be found in both cells.
All amino acids are structurally the same, in that they contain a central carbon atom, an amine group, a lone hydrogen at. Our DNA is contained in our chromosomes. The thing that is different about each of the 20 amino acids is the make-up of the R group
