The fortnight Anne spent in Bolingbroke was a very pleasant one, with a little under current of vague pain and dissatisfaction running through it whenever she thought about Gilbert.
Cell wall. Many types of prokaryotic and eukaryotic cells have a cell wall. The cell wall acts to protect the cell mechanically and chemically from its environment, and is an additional layer of protection to the cell membrane. Different types of cell have cell walls made up of different materials; plant cell walls are primarily made up of cellulose, fungi cell walls are made up of chitin and bacteria cell walls are made up of peptidoglycan.
The cell wall surrounds the cell membrane in plant cells, bacteria, and some fungi. In plant cells, the cell wall is composed of cellulose. In bacteria, the wall is made mostly of polypeptides (protein) or polysaccharides (carbohydrates). The cell wall provides support and protection and is responsible for giving plant cells their shape. Another important structure found only in eukaryotic cells is the nucleus . This struc-ture contains the genetic information and is the control center of the cell. Protecting the nucleus is a double-membrane called the nuclear envelope , which, like the plasma membrane, is semi-permeable.