Module 1 Essay
Cells are the smallest, most basic unit of life. Cells are diverse in size and shape and the sheer number of them. Scientists make the distinction that there are two classes of cells: eukaryotic and prokaryotic. Eukaryotic and prokaryotic cells are similar yet very different. But in addition to the eukaryotic and prokaryotic cells, we have viruses—they are not regarded as life in the scientific community, however, they are important because they infect those which have life (i.e humans). Eukaryotes, prokaryotes and viruses are entities that we come in contact with everyday and therefore need to be studied. There are three prominent ways in which biologists can compare and contrast them: their size and external structures, the …show more content…
However, HIV subsists as a virion outside its host. Therefore, its’ surface is covered in proteins, specifically gp120, which interacts with CD4, a protein on the surface of particular white blood cells, which eventually lead to entry to the host. HIV has a lipid-containing outer envelope derived from host cell membranes upon infection of host. The structures within a cell are measured in two different units: micrometer (μm) and nanometer (nm). A micrometer is equal to 10-6 meters and one nanometer is equal to 10-9 meters. While micro- and nanometers are the most commonly used, the Angstrom (Ӑ), which is one tenth of a nanometer is used for atomic dimensions. Prokaryotic cells typically range from about 1 to 5 micrometers, whereas eukaryotic cells are about 10 to 30 micrometers. In contrast, the HIV virus has a diameter of 100 …show more content…
Starting with prokaryotes—as earlier discussed, prokaryotes have nucleoids—which are regions where their DNA is stored, not membrane bound—plasmids are common, they have no introns and they do not have histones. Eukaryotes have a membrane-bound nucleus where their DNA is stored, plasmids are rare, they have introns (parts of a split gene that correspond to intervening sequence) and they do have histones (collection of small basic proteins of chromatin). Both prokaryotes and eukaryotes have DNA storing chromosomes, however nearly all prokaryotes contain a singular, circular chromosome. Meanwhile, eukaryotic cells usually possess a number of separate chromosomes, each containing a single linear molecule of DNA that are supercoiled and associated with proteins to form chromatin. Let’s take a moment to talk about viruses, and HIV in particular, viruses are not life and are essentially parasitic since they use their infected hosts to provide everything that gives them sustenance. The only thing that all viruses share are some form of nucleic acid (DNA or RNA), but it is an important distinction that both are never contained within one virus. HIV is an atypical virus, a retrovirus, one that contains RNA, which then triggers a process of reverse transcriptase, which creates DNA from RNA, which is the exact opposite of what most cells do. However,
Cells are the smallest, most basic unit of life. Cells are diverse in size and shape and the sheer number of them. Scientists make the distinction that there are two classes of cells: eukaryotic and prokaryotic. Eukaryotic and prokaryotic cells are similar yet very different. But in addition to the eukaryotic and prokaryotic cells, we have viruses—they are not regarded as life in the scientific community, however, they are important because they infect those which have life (i.e humans). Eukaryotes, prokaryotes and viruses are entities that we come in contact with everyday and therefore need to be studied. There are three prominent ways in which biologists can compare and contrast them: their size and external structures, the …show more content…
However, HIV subsists as a virion outside its host. Therefore, its’ surface is covered in proteins, specifically gp120, which interacts with CD4, a protein on the surface of particular white blood cells, which eventually lead to entry to the host. HIV has a lipid-containing outer envelope derived from host cell membranes upon infection of host. The structures within a cell are measured in two different units: micrometer (μm) and nanometer (nm). A micrometer is equal to 10-6 meters and one nanometer is equal to 10-9 meters. While micro- and nanometers are the most commonly used, the Angstrom (Ӑ), which is one tenth of a nanometer is used for atomic dimensions. Prokaryotic cells typically range from about 1 to 5 micrometers, whereas eukaryotic cells are about 10 to 30 micrometers. In contrast, the HIV virus has a diameter of 100 …show more content…
Starting with prokaryotes—as earlier discussed, prokaryotes have nucleoids—which are regions where their DNA is stored, not membrane bound—plasmids are common, they have no introns and they do not have histones. Eukaryotes have a membrane-bound nucleus where their DNA is stored, plasmids are rare, they have introns (parts of a split gene that correspond to intervening sequence) and they do have histones (collection of small basic proteins of chromatin). Both prokaryotes and eukaryotes have DNA storing chromosomes, however nearly all prokaryotes contain a singular, circular chromosome. Meanwhile, eukaryotic cells usually possess a number of separate chromosomes, each containing a single linear molecule of DNA that are supercoiled and associated with proteins to form chromatin. Let’s take a moment to talk about viruses, and HIV in particular, viruses are not life and are essentially parasitic since they use their infected hosts to provide everything that gives them sustenance. The only thing that all viruses share are some form of nucleic acid (DNA or RNA), but it is an important distinction that both are never contained within one virus. HIV is an atypical virus, a retrovirus, one that contains RNA, which then triggers a process of reverse transcriptase, which creates DNA from RNA, which is the exact opposite of what most cells do. However,