Prokaryotic cells are found in organisms such as bacteria, most commonly eubacteria and archae bacteria. Eukaryotic cells are therefore are found in all other living organisms, the name implying that there is a proper nucleus present. As there is no nucleus present in prokaryotic cells the DNA helix is a single coiled chromosome that is unsupported and so can float freely around the cell, however in a eukaryotic cell the DNA helix is made up of linear chromosomes supported by the histone protein. In Eukaryotic cells there is also a distinct nuclear membrane Prokaryotic cells are smaller than Eukaryotic cells, according to “Pharmaceutical Microbiology†the majority of bacteria fall within the general dimensions of 0.75 to 4mm compared to the size of common eukaryotic cells which can be up to 40 times larger than Prokaryotic cells and measure between 50 and 150mm. Prokaryotic cells and Eukaryotic cells both can contain a cell wall however in prokaryotic cells the cell wall is peptidoglycan (a mixture of sugar and protein) if the organism is a eubacteria, or pseudomurein if the organism is a archae bacteria whereas in eukarotic cells a cell wall is only present if the organism is a plant or a fungi and the cell wall is constructed of cellulose in plants or chitin if the organism is a fungi.
They have no internal membranes, no nuclear membrane, no endoplasmic reticulum, no mitochondria and no Golgi body. They do however have a cell wall but it is not made of cellulose. Protoctists are mostly small eukaryotic organisms, with membrane bound organelles and a nucleus, with a nuclear membrane. In this kingdom organisms such as algae, water moulds, slime moulds and protozoa are found. Fungi are also eukaryotic.
Cause and Spread of Infection 1. Understand the Causes of Infection 2.1 Identify the Differences Between Bacteria, Viruses, Fungi and Parasites Viruses are extremely small pieces of nucleic acid that are surrounded by a thin protein coat. They are different from other infectious microorganisms because they cannot replicate outside of a living host cell. They synthesize energy from their host cell and do not have a cell membrane, cell wall or cell nucleus. They have genes but lack a cellular structure.
Antibiotics can usually kill them. An example of bacteria is meningitis and pneumonia. Fungi: A fungus is a spore producing organism that has no chlorophyll and can live as single celled yeast or as a larger multi-cellular mould. It will reproduce by spores. It will live by absorbing certain nutrients from any organic matter.
All of the following are polysaccharides except: q. Glucose 9. Only bacteria cells have cell wall r. False 10. Which of the following terms best describes an organism that cannot exist in the presence of oxygen s. Obligate anaerobe 11. A denatured protein maintains its: t. Primary structure 12. In which stage of the bacterial growth (growth curve), the growth rate is equal to death rate.
It can be seen as a form of transport too, for many different cells. For example, a good example would be red blood cells. A main role of water would be for cohesion. Water molecules can stick to each other, which can create surface tension on the water surface. Cohesion can also make very long and thin water columns, which can be hard to break.
Bacteria are highly successful when reproducing and adapting due to their reproductive time (1-pg. 557). The typical structures of a bacteria cell are as follows, flagella, pili, sex pilus, fimbriae, cell wall, plasma membrane, ribosomes, inclusions, chromosome, and plasmid. Bacteria use something called a flagella, it is a tail looking structure composed of protein, for movement (Citation 9). A pilus is a hair-like characteristic found on the outside of bacteria.
A few of the most noticeable similarities include both having cytoplasm, a plasma membrane, DNA and ribosome’s. Most eukaryotes and prokaryotes also have a cell wall, otherwise known as a structure outside the cell membrane. In addition, the genetic code in a eukaryote and prokaryote are exactly the same. Inside the cytoplasm of a eukaryote is much different than a prokaryote. For instance,
Bacteria are single-celled micro-organisms without a nucleus and a cellular membrane that is made up by protein-sugar molecules. They are a part of the prokaryote kingdom, which is a completely separate group. They are not animals and they are not plants, even though some of them actually show the process of photosynthesis and consequently produce their own nutrients. Most bacteria are between 1 and 10 micrometers long. Bacteria are by far the most common organisms in the world.
Changes in climate or introduction of a new species from elsewhere can greatly affect the balance of nature. Viruses: A virus is a small infectious agent that can replicate only inside the living cells of organisms. Most viruses are too small to be seen. Viruses infect all types of organisms, from animals and plants to bacteria . All viruses have genes made from either DNA or RNA, all have a protein coat that protects these genes; and some have an envelope of fat that surrounds them when they are outside a cell.