The Cell Theory - Essay Example

Lecturer The cell Theory Cell theory involves a scientific theory in the field of biology. The theory explains the cell theory. Cells are the most basic unit of organisms, and also the most basic reproduction unit. The continual advancement of microscopes led to a superior magnification technology that resulted in the cell discovery during the 17th century. Robert Hooke was mainly responsible for the discovery. He initiated cell biology, which is the scientific study that involves cells. Preceding studies in cell biology involves concepts like; cellular regeneration and unit of life. The cell theory was initiated in 1838, by Mathias Schleiden and also Theodor Schwann. The theory are received a lot of contribution from several other scientists; for instance, Rudolf Virchow. The cell unit is the foundational basis of biology. The cell theory has three major aspects. Firstly, living organisms are made up of one, or several cells. Secondly, the basic unit that forms life is the cell. Thirdly, cells develop from the existing living cells (Gilbert 23). Cell discovery as enhanced through the effective microscopic inventions. During first century BC, the Romans discovered that objects appeared bigger when viewed through glass. Salvino D’Armate produced a glass piece that can be worn over one eye, in the 12th century Italy. This created magnification effect on the single eye. In the 1590s, Zacharias Jansen, the Dutch eye glasses designer started to test lenses that can be applied in microscopes. Jansen achieved a magnification of 9x, but the images observed appeared blurred. Jansen and his father developed the first the initial compound microscope in 1595 after several trials. Compound microscope has several lenses in the hollow tube. Robert Hooke mainly used the compound microscope that comprised two convex lenses, with reflected light. Hooke in some cases also used simpler one lens microscope that applied direct transmitted light (Gilbert 47). Robert Hooke’s Microscope The discovery of the cells by Robert Hooke is adequately illustrated in the book Micrographia. The book illustrated 60 images of several objects, as seen through a compound microscope. Observing a thin bottle cork slice, showed several tiny pores. The tiny pores were named cells. The image drawn by Robert Hook, in Micrographia, is illustrated below. The images that Hooke actually believed were cells were in reality the empty plant tissues cell walls. The microscopes during that period had low magnification levels. Hooke did not adequately see the internal components, due to the low magnification. The cell observation by Hooke did not illustrate organelles and nucleus, present in the living cells (Gilbert 36). However, Anton van Leeuwenhoek was the first person to seriously develop and apply the microscope. He had the skills of developing powerful magnifying glasses. The lenses had magnification levels of up to 270x. In the 1880s, Carl Zeiss developed microscopes with lenses that focused on images that measure the wavelength size or greater. The electron microscope was produced in the 1920s. Objects which have smaller sizes, than the wavelength could thus be viewed adequately. The microscopic developments illustrate the superior advancement possibilities in the field of science and technology (Gilbert 39). Drawing of the cork structure Anton van Leeuwenhoek also viewed the cells. He used a microscope that had enhanced lenses, which magnified objects 300 times (270x). Through the microscope, he identified motile objects. Mortality illustrates life characteristics, hence, illustrating living organisms. Leeuwenhoek wrote several papers that illustrates many aspects of the microorganisms. He named the forms animalcules and examples are unicellular organisms such as bacteria and protozoa. Despite limited formal education, he accurately discovered the red blood cells. He also discovered bacteria, by adequately understanding the taste sense through studying the ox tongue (Gilbert 43). Leeuwenhoek was responsible for initialing discovering the sperm cells of humans, and also other animals. Upon discovery, he explained that the fertilization concept entails the sperm cell penetrating the egg cell. This knowledge disapproved the previous cell theory that illustrated spontaneous generation. It was very challenging to prepare thin slices and study the animal tissues; this is because they were very susceptible to tearing and also fragile. Biologists knew that the basic unit of life concept; however, they were unsure of its components and characteristics. It took one century later to inter relate the cellular structure and the presence of plant and animal cells. Henri Dutrochet explained that cells form the basic element of an organization, and that cell entails the psychological unit. J. H. F. and Karl Rudolphi in 1804 won the prize for addressing the concept f the cell. The two were the first scientists to provide evidence that cells possessed independent cell walls. The award was provided by the Royal Society of Science, based in Gottingen. Previous research illustrated that the cells had common walls, and that the fluid passed through the walls (Gilbert 47). The cell theory credit is based on two scientists namely; Matthias Schleiden, and Theodor Schwann. Rudolf Virchow greatly contributed towards development of the theory, but the attribution towards the theory is minimal. Schleiden in explained in 1838, that the structural components of the plants comprised cells. He further explained that cells were produced through the crystallization process occurring outside or within other cells. The crystallization theory was developed years earlier by Barthelemy Dumortier. But, the modern cell theory disputes the concept of crystallization. Schwann explained that just like plants, animals are made up of cells or the structural products of cells. This was a major biological discovery, because minimal information existed concerning the structure of animals. The conclusions on the structure of plants and animals resulted into two cell theory tenets. The first tenet illustrates that living organisms are made up on a single cell or several cells. Secondly, the cell is the fundamental life unit (Gilbert 103). The cell development theory by crystallization that was formulated by Schleiden was effectively disputed by three scientists during the 1850s. The three scientists who disapproved the crystallization perspective are; Albert Kolliker, Robert Remak, and Rudolf Virchow. Rudolf illustrated the third aspect of the cell theory. The tenet is that cells develop out or pre-existing cells. But, the concept of cells developing out of pre-existing cells was earlier explained by Robert Remak. Biological discussions illustrate that Virchow did not give credit to Remak, hence plagiarized his work. Remak explained in 1852 the cell division concept (Gilbert 87). He stated that Schawnn and Schleiden were wrong on the generation schemes. He stressed binary fission ensured the reproduction of additional animal cells. Binary fission knowledge was originally explained by Dumortier. The three tenets completed the classical theory of the cell. The cell theory is interpreted in several ways in the present modern world. There are seven concepts of the modern cell theory. Living cells comprised single or several cells. Secondly, the living cells are produced out of pre-existing cells through cell division process. Thirdly, the cell forms the basic unit of the structure of the organism, and also the functioning of the living organisms. The organism activity is generally dependent on the activities of individual cells, which are independent. The fifth point is that energy flow takes place inside the cells; for instance, biochemistry and also metabolism. Point six illustrates that the cells has the DNA, which is specifically located within the chromosome. The cells also have the RNA, which is specifically located within the cytoplasm and also the cell nucleus. Seven, the cells are generally similar in terms of chemical composition, in all organisms that belong to the same species. In addition, there are three aspects to the modern concept of the theory of the cell. The first modern idea illustrates that the energy flow takes place across the cells. Secondly, hereditary information is transferred from one cell to another through the DNA. Thirdly, all organisms cell have similar foundational chemical composition (Gilbert 109). The modern cell theory illustrates two major categories of cells. The categories are; prokaryotes and eukaryotes. The prokaryotes cell is generally smaller, and the plasma membrane surrounds it. It has unique cell wall, which differs depending on the composition of the organism. The prokaryotes do not have the nucleus; instead they have linear DNA and circular DNA. They also lack other organelles that are membrane bound, though they possess the ribosome. The prokaryote protoplasm has chromosomal region, which looks like fibrous deposits through the microscope. It also has the cytoplasm. The two main examples of the prokaryotes are archaea and bacteria (Gilbert 108). Prokaryote cell The eukaryote has plasma membranes, which surrounds it. However, they possess unique nuclei that are surrounded by the nuclear membrane. Eukaryotic cells have organelles that are membrane bound; for instance, mitochondria, vacuoles, chloroplast and rough endoplasmic reticulum. The eukaryotic cells have organized chromosomes that store genetic material (Gilbert 108). Eukaryotic cell In the first cell theory during the 1830s, the internal component of the cell was referred to as the protoplasm. The protoplasm was illustrated as a jelly like material, also referred to as the living jelly. During the same period the colloidal chemistry concept was developing, and hence the knowledge of bound water arose. The colloid was a component that was between the suspension and the solution. The Brownian motion effect is adequate to hinder sedimentation. The semi-permeable membrane concept was also generated at the same period. The semi-permeable membrane allows solvents to pass through, but hinders the solute materials. In 1827, the osmosis idea was initiated, and it significance in the physiological phenomena identified. In 1877, botanist Pfeffer formulated the membrane theory, as applicable to cell physiology. In the membrane theory, the cell was illustrated as enclosed through a surface with is very thin. The thin surface is plasma membrane (Gilbert 127). The theory further illustrated that, solutes like potassium ion and cell water are found in physical states, just like dilute solution. Hamburger applied hemolysis of the erythrocytes, in the illustration of the permeability nature of the several solutes. Through studying the time needed for cells to increase beyond the elastic level, the rate of solutes being transferred within the cells can be adequately measured through the resultant cell volume changes. Hamburger also observed approximately 50% of the apparent non-solvent of the red blood cells. The explanation for the apparent non-solvent volume is based on the hydration water, and also several other non-solvent compounds within the cells. The cellular life is adequately illustrated in popular culture. Photography has several images showing the cell processes; for instance, the fertilization of the female egg cell. Several film documentaries have been developed to illustrate cell processes such as cell fission. Literary works in science has greatly illustrated the differences between the plant cell and the animal cell. Several other illustration of the cell processes are illustrated in popular entertainment techniques such as music and plays. Work Cited Ling, Gilbert. (2014). In search of the physical basis of life. New York: Plenum Press. Read More