Assume that the mutation leading to abnormal dynein molecule is instead on a gen

Question

Assume that the mutation leading to abnormal dynein molecule is instead on a gene other than the one coding directly for dynein. The mutated gene would then be a gene which codes for a protein involved in controlling some aspect of the process of transcription and translation of the dynein gene to produce dynein. Describe any three particular controls of eukaryotic gene expression which could be affected by the defective, mutated control gene. Note: please describe the normal control process which could be altered, not explain how it is altered in Kartagener’s Syndrome. Please provide a complete, detailed answer. Also, if reference materials were used in your explanation, please site the source.

Explanation / Answer

Prokaryotes are mostly unicellular organisms without a nucleus, in contrast to eukaryotes, organisms that have cell nuclei and may be variously unicellular or multicellular. The difference between prokaryote and eukaryote cell structure is the most important in the living world. Most prokaryotes are bacteria, and the two terms are often treated as synonyms. However, Woese has proposed dividing them into the Bacteria and Archaea (originally Eubacteria and Archaebacteria) on the supposition that these have separate origins. This controversial arrangement is called the three-domain system.

Prokaryotes do not develop or differentiate into multicellular forms. Some bacteria grow in filaments, or masses of cells, but each cell in the colony is identical and capable of independent existence. The cells may be adjacent to one another because they did not separate after cell division or because they remained enclosed in a common sheath or slime layer secreted by the cells. Typically though, there is no continuity or communication between the cells. Prokaryotes are capable of inhabiting almost every place on the earth, from the deep ocean, to the edges of hot springs, to just about every surface of the human body.

The name prokaryote comes from the Greek pros meaning before and karyon meaning nut, referring to the nucleus. Prokaryotes also lack cytoskeletons and membrane-bound cell compartments such as vacuoles, endoplasmic reticulum, mitochondria and chloroplasts. In eukaryotes, the latter perform various metabolic processes and are believed to have been derived from endosymbiotic bacteria. In prokaryotes similar processes occur within the cell membrane, and endosymbionts are extremely rare. They are usually much smaller than eukaryotic cells.

Prokaryotes have a single chromosome, contained within a nucleoid region rather than a membrane-bound nucleus, but may also have various small circular pieces of DNA called plasmids spread throughout the cell. Reproduction is exclusively asexual, through binary fission, where the chromosome is duplicated and attaches to the cell membrane, and then the cell divides in two. However, they show a variety of parasexual processes where DNA is transferred between cells, such as transformation and transduction.

Eukaryotes are organisms with complex cells, in which the genetic material is organized into membrane-bound nuclei. They include the animals, plants, and fungi, which are mostly multicellular, as well as various other groups called protists, many of which are unicellular. In contrast, other organisms such as bacteria lack nuclei and other complex cell structures, and are called prokaryotes. The eukaryotes share a common origin, and are often treated formally as a superkingdom, empire, or domain. The name comes from the Greek eus or true and karyon or nut, referring to the nucleus.

PROKARYOTE CHARACTERISTICS

Prokaryotic cells differ from Eukaryotic cells in several important respects, many of which have already been considered.

1. Size. They are usually much smaller then eukaryotes. 1-5m m rather than 10-100 of eukaryotes. Most are about 1m m.

2. They have no envelope-surrounded nucleus.

3. Their DNA has much less protein associated with it and what is present is easily dislocated. Consequently prokaryotes were long thought to have no protein associated with the DNA.

4. The DNA is a continuous loop, or circle. Smaller circles, or plasmids, may be present.

5. There is no mitosis or meiosis but there is, of course, chromosome replication. Division is by binary fission.

6. There are no independent internal membranes and consequently no membrane surrounded organelles. Thus there are no chloroplasts, mitochondria, lysosomes, endoplasmic reticulum, Golgi.

7. The enzymes, pigments, and electron carriers usually associated with membranes are located on invaginations of the plasma membrane known as mesosomes.

8. The cell wall is unique. It is not cellulose rather another polymer of glucose-like monomers. The polymer is known as a peptidoglycan. These are polymers of substituted glucose crosslinked by short polypeptides. They are known as N-acetylglucosamine and N-acetylmuramic acid. In gram negative bacteria there is also an outer layer of polysaccharide. Protects from lysis in hypoosmotic environment.

9. The cell membrane and cytoplasm are similar to those of eukaryotes except that there is no cytoskeleton in the cytoplasm and no steroids in the membrane.

10. The ribosomes are smaller.

11. There is much less DNA. There is about 1mm of DNA in an E. coli cell whereas one of your cells has about 2m.

12. The flagellum, if present, is radically different from that of eukaryotes. There is no tubulin/dynein system. The flagellum is made of flagellin, and is naked protein outside the membrane.

There are more then 10,000 species of bacteria and their classification is based largely on clinical and laboratory convenience rather than phylogeny. Recent molecular systematic studies have shed some light on the relationships within the Monera.

there apparently was a very early split of the monerans into the Archaebacteria and the Eubacteria. Most modern bacteria are Eubacteria and the Archaebacteria persist as a small number of species largely restricted to extreme environments such as hot springs, high salinities, high acidities, anaerobic environments, etc. e, g, a, d, f. Archaebacteria have no peptidoglycan in the cell wall and have unique phospholipids in the membrane. Ribosomal proteins resemble those of eukaryotes and the archaebacteria may be more closely related to Eukaryotes than are the eubacteria.

The Eubacteria include the gram positive bacteria as well as many groups of gram negative bacteria, the photosynthetic bacteria as well as the Cyanobacteria and spirochaetes.

Any of a group of relatively simple one-celled living things lacking a nucleus and other features found in the more complex cells of all other living things, called eukaryotes. The two major types of prokaryotes are bacteria and cyanobacteria.

The prokaryotes known as archaebacteria are primitive anaerobes (living things that do not require oxygen ) inhabiting extreme environments of high temperature, high salt, or high acidity. All other bacteria are called eubacteria and are classified according to their shape: for example, bacilli are rod-shaped. Eubacteria live in both aerobic (with oxygen) and anaerobic (without oxygen) environments.

Some prokaryotes move by rotating long whip-like structures called flagella. Some species also have slender hair-like extensions called pili, used for attachment. The cell membrane of prokaryotes, similar in structure to that of eukaryotes, is different in composition. Eukaryotes contain organelles, including chloroplasts and mitochondria, that are absent in prokaryotes. Prokaryotes have a single molecule of deoxyribonucleic acid (DNA). This DNA molecule is not enclosed in a nucleus, is not associated with protein, and is not double-stranded, as it is in eukaryotes.

Prokaryotes are cellular organisms lacking a true nucleus and nuclear membrane. Their nuclear material consists of a single double-stranded DNA molecule, not associated with basic proteins. The microorganisms, comprising the bacteria and blue-green bacteria (formerly blue-green algae), are predominantly unicellular but may have filamentous, mycelial, or colonial forms. All (except the Mollicutes and Archaeobacteria) have a true cell wall containing peptidoglycan, and all reproduce by cell fission.

Prokaryotes are the original inhabitants of this planet, the first successful today's would have looked very like some of today's Archaea. Both Archaea and Bacteria evolved somewhere between 3 or 4 billion years ago as far as we are able to tell from the fossil record. This means they have been around twice as long as the Protozoans and more than 3 times as long as animals.

Prokaryotes are the toughest of the tough when it come to living things. They hold all the records for living in the coldest, hottest, most acidic and most highly pressurized environments. They live in incredible places such as miles beneath the earth in bare rock, under glaciers, floating around in clouds and miles down on the sea floor at temperatures greater than 100 C. They are also the worlds experts at surviving bad times. In 2000AD scientists at West Chester University Pennsylvania succeeded in waking up the resting spores of a bacterium (Bacillus permians) that was last active 250 million years ago.

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