Atom and Animal and Plant Cell - Essay Example

? [Teacher’s Defines Atom Breathe in deeply… You have just inhaled billions of atoms comprised of nitrogen, oxygen, carbon and some other pollutant gases in the atmosphere which are released by cars or other factors. Atoms are the smallest indivisible parts of elements and everything on earth. Similarly to the above mentioned example, if you drink a glass of water, you ingest just as many atoms of oxygen, chlorine, hydrogen and fluorine. This principle can also be utilized in several other aspects of life involving the food consumed by people, the gaseous emissions from cars and other complicated everyday utensils like the microchips that are utilized in order for our electronic gadgets to function. Even the books read by students are comprised of atoms. If everything in the world could be divided into the smallest piece possible, it would all look like an atom. It would be very difficult to place atoms in one category of life as they are everywhere and a part of everything around us. The knowledge of atoms has been used in both good and bad things in life. For example, some scientists have used this knowledge to create dangerous weapons such as the atomic bomb. However, the world has tried to reduce the dangers of such weapons by maintaining peace and certain programs that involve countries destroying their nuclear weapons. As mentioned above, several things around us can be broken down to atoms and they are many benefits associated with the knowledge of atoms. In fact, we cannot do anything that does not involve us interacting with elements that contain atoms. Like different elements around us, human bodies have their own equivalent to an atom. Humans are made up of organ systems such as the system that allows us to breathe, the system that allows blood to move all over our bodies and the system that allows us to think and respond to things around us. These are just a few of the systems in the body and they can each be divided into certain organs such as the heart, the lungs or the brain. Each of these organs can also be divided into smaller components which are known as tissues and each tissue is specific to each organ. The tissues can then also be divided into cells which are the human equivalent atoms. Tissues similar to elements, which are each made up of a group of specific atoms that give them their own specific characteristics and properties. However, another interesting factor is that cells themselves are also similar to elements in the sense that they can be divided into macromolecules, which can be divided into molecules. And guess what… these molecules can also be divided into atoms. This has been described by scientists as the organization of life. In more precise terms, a cell can be defined as the basic functional, biological and structural unit of organisms that are classified as living. A cell is often defined as the building block to every living organism. Biologically, the cells have been defined by a scientific theory known as the cell theory. This approach illustrates the properties and structural components of a cell. There are three main components in the cell theory and these include: living organisms of comprise of 1 or more cells; fell on derived from living pre-existing cell and the cell is the most basic functional, organizational and structural unit of all oral living organisms. In addition, cells can also be divided according to the living organism into eukaryotes or prokaryotes. These each have different morphological features including the intracellular components. The atoms in elements can be differentiated by their different nuclear and electronic properties which influence the reactions and characteristics of each element. Human cells on the other hand, are different morphologically in order to suite their particular purposes. Examples of cells include cardio myocytes, neurons, hepatocytes and pneumocytes which all have specific functions in different organs. As mentioned above, different cells can be different in their intracellular components. One main distinguishing feature is the organelles and their quantity in a particular cellular structure. Organelles can be defined as specialized sub units that are found within a cell and perform specific functions. In addition, these organelles are encapsulated with their own membrane. An organelle is similar to an organ such as the heart, brain or lungs. These organs of found inside the body and each perform their own specialized functions. Therefore, similar to these structures, organelles of found within a cell body with each serving its own particular function. Animal and plant cells each have different intracellular components and this paper will focus on the main organelles found in eukaryotes. These include the nucleus, mitochondria, ribosomes, endoplasmic reticulum and Golgi complex. The nucleus is enclosed in a membrane known as the nuclear envelope which contains many holes which are known as nuclear pores. Within the nucleus is nucleoplasm which contains a nucleolus responsible for ribosome production. The main function of the nucleus is to transcript genetic material that will be translated at the ribosomes. This allows for appropriate control of the cell cycle and replication of the genetic material which is also called DNA. After knowing the functions that occur in the nucleus it is easy to see why its membrane contains many holes. These enable synthesized proteins or ribosomes to be released from the nucleus whilst they are small in order to contain larger components of the nucleus such as the nucleolus and chromatin. Mitochondria are often referred to as the energy reserves of a cell and are bounded by an inner and outer membrane. They are responsible for producing energy that is utilized in cellular reactions. One distinguishing feature of mitochondria is that they possess two membranes instead of one like in other cellular organelles. That in the membrane is folded into cristae which make the internal structure look like a simple maze. The reason why the in the membrane is folded this way is to increase the surface area available. If a large surface area is present more chemical reactions will be able to take place within the organelle. This is important because many processes in the cell require energy and the mitochondria have to work fast in order to meet the cellular demands. In other words, if there is more working space available one is able to do more work. The endoplasmic reticulum and Golgi apparatus are connected in their functions and they together produce macromolecules for exocytosis and lipids and lysosomes which are utilized in breaking down certain products. There are two types of endoplasmic reticulum which include rough endoplasmic reticulum and smooth endoplasmic reticulum. The two differ in both their structure and functions; however they each contain a continuous membrane. Rough endoplasmic reticulum has ribosomes which are absent in smooth endoplasmic reticulum. The membrane surrounding RER is continuous from the nuclear envelope and its ribosomes are responsible for the synthesis of different functional polypeptides which are encapsulated would and that RER and secreted to the Golgi apparatus. As mentioned above, the Golgi further processes these polypeptides and releases them into the cytoplasm mainly for exocytosis. Ribosomes are comprised of two sub units which are responsible for the translation of mRNA resulting in protein synthesis inside the cell. Ribosomes may either be located freely within the cytoplasm or on the membrane of RER. Smooth endoplasmic reticulum is continuously formed from RER and has a structure similar to a complex network of tubes. The majority of its reactions occur inside the cell and often involve many enzymatic processes. This results in the synthesis of lipids such as steroids, phospholipids and fatty acids. As mentioned above, different organisms possess different types of cells. These include plant, animal and bacterial cells. Both plant and animal cells are eukaryote whilst bacterial cells are prokaryotes. The above mentioned terms simply mean animals and plants are part of a multi-cellular system whilst of bacteria are unicellular. There are also several differences between plant and animal cells which include the fact that animal cells do not have a cell wall which is present in plant cells. On the other hand, bacterial cell walls are made from murein whilst plant cell walls are compromised of cellulose. There is also a difference in the ribosomes as the ones present in eukaryotes are 80S and prokaryotes are 70S. Plant cells have plastids which contain chlorophyll. These are not to present in both bacteria and animal cells. Chlorophyll is the reason why plants are green. Plants also need to maintain a certain pressure hence they possess vacuoles which are filled with water and maintain turgidity in the cell. Plant and animal cells keep their DNA material inside the nucleus which is surrounded by a nuclear membrane with nuclear pores. However, the DNA in bacteria cells lies freely in the cytoplasm. The cells also contain plasmids, which are DNA molecules capable of dividing without receiving a message from chromosomal DNA. There are also scientific theories suggesting the evolution of single celled organisms into multicellular ones. Scientists have discovered that a large number of the oldest cells are bacteria which are unicellular (Ratcliff, 1595-1600). Hence, this has raised questions on the origins of multicellular organisms and given birth to the theory of cellular evolution. The theory based on fossil records believes that millions of years ago the earth was covered by bacteria which utilized CO2 and solar energy as nutritional components. This process is still present in plant cells and is known as photosynthesis. The byproduct of this process is oxygen, which was released into the atmosphere. Therefore, the release of this new gaseous product was able to give a lifeline for new species; hence, oxygen dependent cells were able to survive on earth (Ratcliff, 1595-1600). Similar to this, single cells are also believed to have evolved at least twenty five times. They are believed to have evolved into 6 eukaryotic categories which include fungi, animals, brown algae, green algae, plants and red algae. Plants are assumed to have evolved repeatedly whilst animals are towards to have evolved a maximum of two times. Multicellular organisms were first seen in bacteria known as cyanobacteria many years ago (Ratcliff, 1595-1600). Since multicellular organisms require regeneration from germ cells, the Mesoproterozoic era is assumed to be the period when sexual reproduction began and hence the first multicellular organisms were created (Ratcliff, 1595-1600). Therefore, it is clear that the atom and the cell are two fundamental components of living organisms and the things around them. Cells contain different organelles and structures that enable them to perform certain functions. Below are pictures of different cell types and atoms. Atom Source: Nuclear Physics Atom. Mizonuphys.blogspot.com Prokaryotes Source : Maria Ruiz. 2006. Animal and Plant Cell Source: Sikeston.k.12.m0.us Works Cited Maria Ruiz Prokaryotes. 2006. Web. 3 0ctober 2013 Nuclear Physics Atom. Mizonuphys. 2010. Web. 3 October 2013 Ratcliff, William C., et al. "Experimental evolution of multicellularity." Proceedings of the National Academy of Sciences 109.5 (2012):1595-1600. Reece, Urry. "Campbell Biology." (2011). 20-65 Plant and Animal cells. Sikeston.k12.mo.us. n.d Web. 3 October 2013 Read More