Advantages And Disadvantages Of Prokaryotes

When life arose on Earth about 4 billion years ago, the first types of cells to evolve were prokaryotic cells. For approximately 2 billion years, prokaryotic-type cells were the only form of life on Earth. The oldest known sedimentary rocks found in Greenland are about 3.8 billion years old. The oldest known fossils are prokaryotic cells, 3.5 billion years in age, found in Western Australia and South Africa. The nature of these fossils, and the chemical composition of the rocks in which they are found, indicates that these first cells made use of simple chemical reactions to produce energy for their metabolism and growth. Eukaryotic cells evolved into being between 1.5 and 2 billion years ago. Eukaryotic cells appear to have arisen from prokaryotic cells, specifically out of the archaea. Indeed, there are many similarities in molecular biology of contemporary archaea and eukaryotes. However, the origin of the eukaryotic organelles, specifically chloroplasts and mitochondria, is explained by evolutionary associations between primitive nucleated cells and certain respiratory and photosynthetic bacteria, which led to the development of these organelles and the associated explosion of eukaryotic diversity. Today Prokaryotes

Endosymbiosis is the theory that eukaryotic cells were formed when a prokaryotic cell ingested some aerobic bacteria. The first step of the evolution of a eukaryotic cell is the infolding of the cellular membrane. This process takes place when the plasma membrane folds inwards and develops an envelope around a smaller prokaryotic cell. Once the smaller cell is engulfed, it becomes dependent upon its host cell. It relies on the host cell for organic molecules and inorganic compounds. However, the host cell also benefits because it has an increased output of ATP for cellular activities and becomes more productive. This ATP comes from the mitochondrion (the aerobe) that is engulfed.

Microbes are bacteria, archaea and eukaryotes. The earth was formed 4.6 million years ago. And a few million years later, by 3.5 billion years ago, earth was already inhabited by a diversity of organisms. The earliest organism is Prokaryotes and within the next billion years, two distinct groups of prokaryotes called bacteria and archaea diverged. Eukaryotes cell evolved from a prokaryotes community, a host cell containing even smaller prokaryotes .The microbial world accounted for all known life forms for nearly 50 to 90% of Earth's history. We are still researching microbial organisms today in marine environment, extreme environments. A microbial observatory is an NSF-funded project dedicated to the discovery and characterization of novel microorganisms and microbial communities of diverse

There are three domains of organisms, which are Bacteria, Archaea, and Eukarya. Domain Bacteria and Domain Archaea prokaryotes, and Domain Eukarya inevitably includes eukaryotes. Prokaryotes are the most abundant and able to adapt to many different environments. They do not contain a nucleus, circular DNA,

Ribosomes then started copy themselves into cell-like structure with a thin membrane and cytoplasm. Eventually, cells starting storing DNA. Lateral transfer diversified the cells genetic makeup. From this community of cells came the three domains, known as bacteria, eukaryotes, and archaea. Bacteria and archaea are together called

Bacteria and Archaea are prokaryotic, which are mostly single-celled incomplex microorganisms. Both Bacteria and Archaea have a variety of prokaryotes classified in multiple kingdoms (Reece, et al., Campbell Biology, 2014). There are a number of scientists who believe that Archaea cells may be the precursor to Eukaryotic cells and that they have more in common with Eukaryotes than Prokaryotes (Madigan, Martinko, & Dunlap, 2009).

25. The formation of a phospholipid bilayer membrane around a set of macromolecules was an important step in the origin and early evolution of life. What two advantages of such a system are thought to have allowed the first cells to grow and evolve? (1) The membrane forms a (semipermeable) barrier between the interior of the cell and its environment, and (2) it allows a cell to grow and evolve as a unit, instead of existing as isolated molecules.

Eukaryotes and bacteria cells both have the common cell structure of flagella. Flagella is considered a protein. The purpose of the flagella is to help the cell move. Eukaryotes have a different movement type than bacteria. Eukaryotes move in form of an s-shape. Bacterial cells move like helicopter blades (rotor type movement). The flagellum of the bacterial cell are a lot thinner the eukaryote due to the size of the cell.

Now that we understand the properties of life and the composition of cells, we can focus on the architecture or formation in terms of basic anatomy and physiology as our second area of exploration. The two types of cells (prokaryotic and eukaryotic) defined before have a few common things such as Plasma membrane (similar to animal cells); Cell wall (similar to plant cells); and Ribosomes, the

Passing the cell membrane we find that, eukaryotes have a complex cytoskeleton. Their cytoskeleton consists of a complex network of elements called microtubules and actin filaments. The cytoskeleton not only anchors the cell, but it also aids in movement. Another aid of movement is cilia. Cilia are shorter than flagella and are more numerous. This movement of the cell helps to propel substances across the surface. This movement mechanism is only found in eukaryotes. Prokaryotes do not have cilia, they only have flagella. Flagella also vary from prokaryotes to eukaryotes. Prokaryotes have flagella that are made from flagellin, whereas eukaryotes have flagella that are made from microtubules. They are similar in structure, but differ in the proteins that are used to make them. Moving inside the cell we find ribosomes which both prokaryotes and eukaryotes have. They are similar in function, synthesis organelle and ribosomal RNA sequencing, but not in density. Prokaryotes have a 70S ribosome and eukaryotes have a 80s ribosome. Speaking of proteins, eukaryotes have histones. Histones are proteins that help organize the DNA and order it into

The plasma membrane is the outermost layer of a eukaryotic cell. It is made up of phospholipids and proteins. The plasma membrane also functions as the selective boundary of the cell. Unlike a prokaryotic cell, a eukaryotic cell has a nucleus. The nucleus is responsible for the storage and the protection of the DNA of the cell. Most eukaryotes possess a endomembrane system. The endomembrane consists of a endoplasmic reticulum, the golgi apparatus, and vesicles. The endomembrane makes lipids and membrane proteins and sends them where they need to go in the cell. Mitochondria are important parts of eukaryotic cells because they transfer the energy needed for the ATP from food molecules. Lastly, one of the major components of a eukaryotic cell is the cytoskeleton. The cytoskeleton is made up of actin microfilaments, microtubules, and intermediate filaments. The cytoskeleton gives the structure of the eukaryotic cell support. It also assists with the division of the cell and it controls cellular

3. Tortora GJ. Functional Anatomy of Prokaryotic and Eukaryotic Cells. In: Microbiology an Introduction. 9th ed. San Francisco, CA: Pearson Education, Inc; 2007: 77-113.

Prokaryotic Cells All living things are made of cells, and cells are the smallest units that can be alive. Life on Earth is classified into five kingdoms, and they each have their own characteristic kind of cell. However the biggest division is between the cells of the prokaryote kingdom (monera, the bacteria) and those of the other four kingdoms (animals, plants, fungi and protoctista), which are all eukaryotic cells. Prokaryotic cells are smaller and simpler than eukaryotic cells, and do not have a nucleus. Prokaryotic means 'pre-nucleus' and eukaryotic means 'true nucleus'.

Eukaryotes come in two grades of organization: single-celled (protists) and multicellular (plants, animals, and fungi). The world today is full of complex multicellular plants and animals: how, why, and when did they evolve from protists?

Even though both Archaea and eubacteria have a cell wall to maintain rigidity throughout the cell, there are