Compare and contrast the structure and function of prokaryotic and eukaryotic cells.
Prokaryotic cells are single celled organisms that were formed at the formation of the earth, so are the most basic life forms. The prokaryotes are organised in the ‘three domain system’ and include bacteria and blue-green algae. Prokaryotes live in many environments including extreme habitats such as hydrothermal vents, hot springs, swamps, wetlands, and the guts of animals.
This is a diagram of a prokaryote cell and it shows that they are not very complex cells. They do not contain any membrane bound organelles and they have relatively small ribosomes. They also do not contain and endoplasmic reticulum.1 The DNA is not stored in a nucleus but it is stored in the nucleoid. DNA in the cytoplasm and many prokaryotic cells also contain very small loops of DNA called plasmids. The nucleoid region is the area of the cytoplasm, which contains the single bacterial DNA molecule. Some prokaryotic cells have a capsule, which is an outer layer of protection which protects the cell when being engulfed by other organisms. It also helps the cell stick to surfaces and nutrients. The cell wall (which contains murein) protects and gives the cell shape. In the centre of the cell there is the cytoplasm which is composed mainly of water but also contains digestive enzymes, salts, organelles and other organic molecules. The prokaryotic cell also has a cell or plasma membrane which controls the movement of substances in and out of the cell. The pili are short, hair-like structures which attach the cell to other bacterial cells. Finally, the bacterial flagellum is a long ‘tail’ which helps the cell move.2
Prokaryotic cells can be harmful as they are bacterial cells and therefore can cause disease. Some of these bacteria have developed a resistance to antibiotics, for example, MRSA. The resistance becomes coded on the plasmid DNA and as the bacteria can share the plasmid between each other, the resistance can bass between the cells. Also, as prokaryotic cells reproduce asexually
This is a diagram of a prokaryote cell and it shows that they are not very complex cells. They do not contain any membrane bound organelles and they have relatively small ribosomes. They also do not contain and endoplasmic reticulum.1 The DNA is not stored in a nucleus but it is stored in the nucleoid. DNA in the cytoplasm and many prokaryotic cells also contain very small loops of DNA called plasmids. The nucleoid region is the area of the cytoplasm, which contains the single bacterial DNA molecule. Some prokaryotic cells have a capsule, which is an outer layer of protection which protects the cell when being engulfed by other organisms. It also helps the cell stick to surfaces and nutrients. The cell wall (which contains murein) protects and gives the cell shape. In the centre of the cell there is the cytoplasm which is composed mainly of water but also contains digestive enzymes, salts, organelles and other organic molecules. The prokaryotic cell also has a cell or plasma membrane which controls the movement of substances in and out of the cell. The pili are short, hair-like structures which attach the cell to other bacterial cells. Finally, the bacterial flagellum is a long ‘tail’ which helps the cell move.2
Prokaryotic cells can be harmful as they are bacterial cells and therefore can cause disease. Some of these bacteria have developed a resistance to antibiotics, for example, MRSA. The resistance becomes coded on the plasmid DNA and as the bacteria can share the plasmid between each other, the resistance can bass between the cells. Also, as prokaryotic cells reproduce asexually