• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Discuss how Prokaryotes are the same as Eukaryotes.

Extracts from this document...


Discuss how Prokaryotes are the same as Eukaryotes All living organisms can be classified into two distinct groups: eukaryotes and prokaryotes. These two groups are classified on the basis of their cell structure. The barrier between the two groups essentially divides single-celled primitive cells from the more complex variety of multicellular organisms. In truth, however, the word, eukaryote can be broken into eu from the Greek meaning "truly", and karyon meaning "nucleus", in combination, reading "truly nucleated". Although both eukaryotes and prokaryotes contain common structures, each has its own distinguishing features. Prokaryotic cells have no membrane-bound organelles. This means their DNA is naked, circular and lies free in the cytoplasm, and forms a plasmid. Eukaryotic cells, on the other hand, have double membrane-bound nuclei in which the non-circular chromosomal DNA is contained. Eukaryotes have much larger mass due to their greater size. A bacterium such as E. coli has a mass of about 0.5p; a eukaryotic cell 30�m in diameter has a mass of 14ng. Eukaryotes therefore have a surface area to volume ratio of more than 10 times lower than that of prokaryotes. Eukaryotes are also 10-50 times the length or diameter of prokaryotes and therefore house larger varieties of ribosomes i.e. they contain 22nm ribosomes rather than the 18nm ribosomes in prokaryotes. ...read more.


All eukaryotic organisms are formed from many cells clustered together, each with their own specific role, and often gathered into groups of similar cells, called organs. In this way, it can be seen, that both types of cell, can act as building blocks for larger organisms. These common features may be thought to be related to the idea of a common ancestor. This theory suggests that all living organism originated from a common cell, which then divided into different groups via speciation methods. Common features are also related to the endosymbiotic theory, which proposes that eukaryotes evolved from prokaryotes. Eukaryotes contain ribosomes that are semi-autonomous, and have their own DNA, ribosomes, mRNA and tRNA. It was gradually realised that DNA, RNA and protein synthesis in mitochondria and chloroplast display more similarities to the cognate processes in prokaryotic cells than to those in eukaryotic cells. From this realisation, came the endosymbiotic theory which adds to the argument that prokaryotes are the same as eukaryotes, because from this theory, one can see that eukaryotes are heavily dependent on the processes that prokaryotes have given them in this symbiosis. It is the transformation of chloroplasts and mitochondria from prokaryotes that has allowed eukaryotes to respire especially in atmospheres lacking in oxygen; and since these features are two of ...read more.


A feature of eukaryotes is also their ability to transport materials into and out of the cell in bulk, i.e. not just by diffusion by carrier proteins in the cell membrane. They can do this via endocytosis and exoxytosis, processes which are unique to eukaryotes. In endocytosis, portions of the membrane invaginate and are pinched off to form membrane-bounded cytoplasmic vesicles, containing substances that were previously on the outside of the cell. Exocytosis is the opposite of this process and involves membrane-bounded vesicles inside the cell fusing with the plasma membrane and releasing their contents to the outside of the cell. As a summary, it has been shown that eukaryotes and prokaryotes have many cellular similarities, as do many different organisms, but in general, they differ greatly in their morphological structure, and hence the reason they are classed into different taxonomist classifications. Word Count = 2057 Becker, W.M., Kleinsmith, L.J. and Hardin, J. (2000). The World of the Cell. 4th ed. San Francisco: The Benjamin/Cummings Imprint. Jones, M., Fosbery, R. and Taylor, D. (2000). Biology 1. Cambridge, Cambridge University Press. Jones, M. and Gregory, J. (2001). Biology 2. Cambridge: Cambridge University Press. Alberts, B., Johnson, A., Lewis, J., Raff, M., Roberts, K. and Walter, P. (2002). Molecular Biology of the Cell. 4th ed. New York: Garland Science. Biology of Cells supervision (Sarah Jarmin) Jessica Beveridge Due 28/10/02 ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Molecules & Cells section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Molecules & Cells essays

  1. Comparing Eukaryotic and Prokaryotic cells.

    which is an infolding of the plasma membrane, which is related to cell division and replication, this cell structure is not found in a eukaryotic cell. In a prokaryotic cell the asexual reproduction of the cell takes place by binary fission which is the splitting of two cells in half

  2. Eukaryotes and Prokaryotes

    Eukaryotic cells are usually between 10-100 micrometers across. - Structure All eukaryotic cells have certain characteristics in common; these are shown in the diagram below. This table is take from www.botany.uwc.ac.za, which shows the structural difference between animal and plant cells (both eukaryotic cells).

  1. Describe the difference between prokaryotic and eukaryotic cells. Describe the theory of endosymbiosis and ...

    These organelles are important for organisms that photosynthesize. Some prokaryotes have infoldings of the plasma membrane, like mesosomes. In this case, chlorophylls and enzymes are embedded to form a membrane called thylakoids. These photosynthetic membranes are only present in photosynthetic bacteria of prokaryotes.

  2. The Structure of Prokaryotic and Eukaryotic cells.

    This substance, peptidoglycan, consists of a mucopolysaccharide and a polypeptide combined together. The composure of this cell wall is totally different from the cell wall of a plant cell. The cell wall of a plant cell is made up of various different layers with substances including pectin and cellulose.

  1. Four organelles or structures that all eukaryotic cells have in common.Introduction.The cell as it ...

    Core electrons (those in the outer shell) play a role, but it is usually in terms of a secondary effect due to screening of the positive charge in the atomic nucleus. There are different types of chemical reactions. They include endergenic reaction and endergenic reactions.

  2. Compare and contrast a motor nuerone and a bacterium

    They receive this information from other neurons and transmit it away from the brain, to the muscles and glands and are referred to as dendrites.

  1. Investigating the permeability of plant cells.

    This is called facilitated diffusion, in which the molecule moves down its concentration gradient. Or it can be more complicated business of pumping the required molecule across the membrane from a region of low concentration to an area of high concentration, this is known as active transport. Membrane Transport Mechanisms.

  2. Distinguish between prokaryotic and eukaryotic cells. Compare and contrast the structures of a plant ...

    Along with cell identification and cell adhesion, the cell surface membrane allows the exchange and transport of materials into and out of the cell. The cell surface membrane is made up of two layers of phospholipids (fluid mosaic model) and this structure is important for the function of diffusion.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work