Cell structures come in various shapes and sizes dependent on their location within an organism and what life sustaining process it carries out. These can range from the globular protein of a red blood cell, designed to carry four oxygen molecules at a time to the tail like flagellum of a bacteria designed for mobility and penetration of organs within a body.
There are two main types of cells, eukaryotic cells which are generally plant and animal cells and prokaryotic cells, which relate to organisms such as bacteria and fungi, which undergo asexual reproduction. They both contain organelles such as ribosomes and mitochondria for functions such as protein synthesis and producing ATP from an energy source such as glucose. There is theories which suggest that mitochondria, although now cell organelles, originally were prokaryotic cells as of their unique features such as a double membrane and its storage of DNA. Mitochondria are important in such cells as villi and microvilli, which rely on the production of ATP for the transportation of important products of digestion against their concentration gradient. Villi/microvilli are finger like projections found on the wall of the small intestine which are folded several times to increase their surface area for maximum absorption. They have a rich blood supply to maintain a concentration gradient and are able to move food throughout the small intestine.
The villi are subject to infiltration by other cells such as prokaryotes – namely chorea whose structure is designed to deal with the conditions of the human digestive system. They contain a flagellum to aid movement through the digestive system, a cell wall/capsule to protect against mechanical damage and help bind to other bacteria. The most potentially dangerous feature of a bacterium is its plasmid. These can contain information for such features as the breaking down of antibiotics, which form due to a