Their cell membranes are made with different material than bacteria. Just like bacteria, archaea are also single cell and are surrounded by a cell wall. Eukaryotes, unlike bacteria and archaea, contain a nucleus. And like bacteria and archaea, eukaryotes have a cell wall. The Gram stain is a system used to characterize bacteria based on the structural characteristics of their cell walls.
All living things are either prokaryotes or eukaryotes and the difference is determined by the function and structure of their cells. Prokaryotes known as the first living organism on earth only process one membrane called the plasma membrane. They contain ribosomes and a nucleoid which also lack membranes. The eukaryotic cell is a complex structure that contains a membrane-bound organelles, like a nucleus where their genic material is stored and organized. The prokaryotes are smaller in size than the eukaryotic cells they differ in number of chromosomes the eukaryotes have more than one, and the prokaryotic cells only have plasmids.
Within the cell is genetic material, deoxyribonucleic acid (DNA), containing coded instructions for the behavior and reproduction of the cell and also the chemical machinery for the translation of these instructions into the manufacture of proteins. Viruses are not considered cells because they lack this translation machinery; they must parasitize cells in order to translate their own genetic code and reproduce themselves. Cells are of two distinctly different types, prokaryotes and eukaryotes; thus, the living world is divided into two broad categories. The DNA of prokaryotes is a single molecule in direct contact with the cell cytoplasm, whereas the DNA of eukaryotes is much greater in amount and diversity and is contained within a nucleus separated from the cell cytoplasm by a membranous nuclear envelope. Many eukaryotic cells are further divided into compartments by internal membranes in addition to the nuclear envelope, whereas prokaryotic cells never contain completely internal membranes.
Prokaryotic means 'pre-nucleus' and eukaryotic means 'true nucleus'. The nucleus in eukaryotic cells contains the DNA in linear chromosomes and is bounded by a nuclear membrane, but since a prokaryotic cell doesn't have a nucleus and its DNA is a single, circular coiled molecule that floats freely within the cell and is not bounded by nuclear membrane nor is it complexed with any proteins. In addition to the circular DNA some bacteria also contain plasmids. Prokaryotic cells are far older and more diverse than eukaryotic cells. Prokaryotic cells have probably been around for 3.5 billion years, which is about 2.5 billion years longer than eukaryotic cells.
Part A Prokaryotic and Eukaryotic Cells Introduction Prokaryotic and Eukaryotic cells are both found in living thing, they have similarities and differences. This will be discussed further on in the essay. Prokaryotic cells are found in organism like bacteria which are archaebacterial and eubacteria whereas, eukaryotic cell are found in animals and plants. Prokaryotic cells Bacteria are prokaryotes, opposing from eukaryotes in having no membrane-bound nucleus or double- membrane organelles. Bacteria are an ancient group of tiny cellular organism which can be a size from 0.1 to 10 µm; they have colonised the earth for more than 3500 million years (Kent, 2013).
b) DNA is a double helix and it replicates itself by separating the two strands while each serves as a template for new nucleotides to pair up into two new complementary strands. In prokaryotes, DNA is located all over the cell, but in eukaryotes it is only in the nucleus, and more specifically on their chromosomes. Prokaryotic DNA are located in loops, and does not contain the proteins found in eukaryotic DNA. Prokaryotes DNA has less unhelpful DNA than eukaryotes do, who have about 95% unhelpful DNA. Prokaryotes also have less complex transcriptional regulatory mechanisms than eukaryotes.
The host cell, chronocyte, was not a prokaryotic cell but one that had a cytoskeleton composed of actin and tubulin and a complex membrane system. The chronocyte contributed to the end product that is the euaryotic cell. Its contributions were the cytoskeleton, endoplasmic reticulum, Golgi apparatus, and major intracellular control systems. (3) References 1) Prescott, Lansing. Microbiology: 6th Edition.
(Miller, 139) DNA is the genetic material found in most viruses and in all cellular organisms. Some viruses do not have DNA, but contain RNA instead. Depending on the organism, most DNA is found within a single chromosome like bacteria, or in several chromosomes like most other living things. (Heath, 110) DNA can also be found outside of chromosomes. It can be found in cell organelles such as plasmids in bacteria, also in chloroplasts in plants, and mitochondria in plants and animals.
There are two types of ER. One of them is Rough ER that has an outer surface lined with ribosomes and is involved in the synthesis of proteins and there is Smooth ER that has no ribosomes and is concerned with the synthesis of lipids and steroids. (Clamp, 2000, pg. 52) Ribosomes are spherical structures composed of ribosome RNA and protein, they are very small organelles and they act as a site of protein synthesis in a cell. They are found free in the cytoplasm and attached to ER (making it rough ER).
The study of viruses, bacteria, and protists has been going on for some time now. A virus is classified as an infective agent that typically consists of a nucleic acid molecule in a protein coat; it is too small to be seen by a light microscope. A virus is also able to multiply only within the living cells of a host. A bacterium is classified as a member of a large group of unicellular microorganisms that have cell walls, but lack organelles and an organized nucleus, including some that can cause disease. Protists are a large and diverse group of eukaryotic microorganisms, which belong to the kingdom Protista.