General characteristics of viruses biology libretexts. Bacteria article about bacteria by the free dictionary. The bacteria may be spherical, rodlike, spirally coiled or filament like. What are the characteristics of a pathogenic bacteria. The cell is complex in its makeup and its function. These prokaryotes generally have a cell wall, plasmid dna, some form of movement or communication system with other bacteria and are heterotrophic. Bacteria vary from species to species, thus assigning many common traits to bacteria is difficult. The shape of bacteria is very characteristic to them. Majority of pathogenic bacteria grow best at neutral or slightly alkaline ph 7. In general, bacteria survive alkaline ph better than acid ph, but a few strains actually. A clump of a few million identical bacteria originating from the same bacterium. Qualitative characteristics of lactobacillus bulgaricus. Classification of bacteria by shape or cell structure cohn divided the bacterial into four types based on their shapes in 1872. These bacterial structures have a specific shape like a stick bacilli, spherical cocci, coma cholera bact.
These structures are cell wall, cell membrane, cytoplasm, ribosomes and the chromosome. Bacteria definition, shapes, characteristics, types. Laboratory manual of standardized methods for antimicrobial sensitivity tests for bacteria isolated from aquatic animals and environment. So, most pathogenic bacteria of human have optimum growth temperature of about 3537. Review the criteria for bacterial classification and identification discuss the principles underlying the biochemical, staining and molecular techniques used for classification, identification and diagnosis illustrate the clinical applications of these diagnostic techniques emphasize the. Characteristics of bacteria june 7, 2017 amber taylor introduction microbiology. Test yourself on your knowledge of the characteristics of bacteria with an interactive quiz and a printable worksheet. Compare and contrast classification and identification.
The o antigen distinguishes serotypes stains of a bacterial species e. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Look at the picture to the right as you read each part. Apr 18, 2016 bacteria are the most abundant group of microorganisms in nature. A healthy human digestive tract depends on the help of particular microbes to break down and process the foods we eat. Bacterial cell morphology, staining reactions, classification of bacteria the protoplast is bounded peripherally has a very thin, elastic and semipermeable cytoplasmic membrane a conventional phospholipid bilayer.
Bacteria contain their dna and other genetic material as a single strand in their cytoplasm, and they reproduce through a process called binary fission. Microorganisms are the smallest organisms on earth. Students learn and understand the significance of bacterial isolation in applied biotechnology. Qualitative characteristics of lactobacillus bulgaricus and. General characteristics of bacteria bacteria are prokaryotic organisms kingdom. Morphology and classification of bacteria microbiology module microbiology notes 1. Common structures bacteria cell transfer dna under protein conjugation f or sex pili plasmids extrachromosomal dna dna chromosomes genetic material dna carbohydrate, lipid, protein, salts reservelager for n. Characteristic gramnegative bacteria grampositive bacteria wall structure they have a thin lipopolysaccharide exterior cell wall. Gram staining is used for general identification of bacteria or to detect. Dec 27, 2017 pathogenic bacteria may have one or more of the following characteristics. Gram staining is the application of a crystal violet dye to a culture of bacteria. Microorganisms that contain chloroplasts and carry out photosynthesis, like algae and singlecelled plants, process carbon.
Bacteria vary in their physiology and are biochemically very active. Explain the scientific naming differentiate between culture, clone, and strain. Using theses bacterial culture techniques students discover and isolate the bacteria present around us. Bacteria are typically singlecelled organisms called prokaryotes that may serve as digestive aids, cause disease or aid in decomposition. Bacteria reproduced by binary fission or conjugation. Like all cells, bacteria have a plasma membrane that controls what can enter and leave the cell. Bacteria such as bacteroides found in the large bowel are examples of anaerobes. This quiz and worksheet combo can help you quickly determine your understanding of bacterial plasmids and the characteristics they have. Start studying characteristics of bacteria worksheet. Bacteria are the most abundant group of microorganisms in nature. Bacterial genetics are subtly different from eukaryotic genetics, however bacteria still serve as a good model for animal genetic studies. Bacteria, along with other organisms, are responsible for the breaking down of organic waste, and an understanding of their characteristics is critical to pollution control technologies. Bacterial classification, structure and function introduction the purpose of this lecture is to introduce you to terminology used in microbiology.
General characteristics, structure and taxonomy of viruses. In fact, the term microorganism literally means microscopic organism. Microorganisms may be composed of prokaryotic or eukaryotic cells, and they may be singlecelled or multicellular. Difference between gram positive and gram negative bacteria. Bacteria lack the high degree of internal compartmentalization characteristic of eukaryotes.
In this session we will focus on summarising what you need to know about. The most important microorganisms relevant to biotechnology include bacteria, fungi, and viruses. The gram staining method was first described in 1844 by the danish bacteriologist hans christian gram, after whom the test was named. There are bacteria all over our skin, even on our eyelashes. Bacteria multiply by transversal division less frequently by elongation and budding. Though many different types of bacteria are known, they share some common characteristics. There are three notable common traits of bacteria, 1 lack of membranebound organelles, 2 unicellular and 3 small usually microscopic size. They have optimal growth temperate that corresponds to the body temperature of host. Some bacteria can cause diseases for human, animals and plants. Also easily determine which media should be used for each bacteria listed. The gram stain attaches to peptidoglycan in the bacterial cell wall. Bacteria that retain the color of the dye are called gram positive. Example of important bacterial characteristics for vibrio. Properties and classification of microorganisms since the cell is the basic unit of all living things, you might think it is a simple structure.
Difference between gram positive and gram negative. That is why in 1 g of a probiotic product from a physical point of view there cannot be so many cells of lactobacillus bulgaricus, as for example of bifidobakterium. The branch which is deals with bacteria is known as bacteriology. Bacteria are classified by their gram stain characteristics. Discuss why bacteria can be cultivated on synthetic media such as nutrient broth whereas viruses cannot.
However, among bacteria there are also microorganisms which have spherelike, threadlike, or coiled shapes. Jul 27, 2015 medical microbiology lecture power point ppt basic characters of bacteria slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. The vast majority of bacteria have a rodlike shape. Bacteria are distinct living entities whose structural organization differs from that of all other microorganisms except bluegreen algae. Many viruses contain an external membrane called an envelope. Often regarded as the simplest life forms, bacteria make up a diverse group of organisms. Ideas bacteria are usually unicellular prokaryotes. Start studying general characteristics of bacteria. Many scientists have spent their lives studying it. It is also easy for the identification of bacteria by recognition of shapes. In discussions of wwtps the terms bugs and bacteria are generally used to describe the.
Lipid a is identical for related bacteria is similar for all gramnegative enterobacteriaceae. Outside, and closely covering this, lies the rigid, supporting cell wall. Staphylococcus aureus gastroenteritis toxic shock syndrome. The classification helps in identification of organisms according to groups. The core region is the same for a species of bacteria. List the characteristics of the bacteria, archaea, and eukarya domains. Science photo library cdcbrand x picturesgetty images. They lack organized nucleus, but possess a rigid cell wall comparable to that found in plants. Characteristics of bacteria chart download pdf determine the characteristics of bacteria such as shape, mobility, gram staining results, and incubation temperatures. Most bacteria singular, bacterium are very small, on the order of a few micrometers m 10. In contrast, strictly anaerobic bacteria grow only in conditions where there is minimal or no oxygen present in the environment. Despite this diversity, bacteria share a number of characteristics, most notably having prokaryotic cells.
Bacterial classification, structure and function columbia university. Facultatively anaerobic bacteria can grow in high oxygen or low oxygen content and are among the more versatile bacteria. Viruses basic structure and general characteristics diseases medical biotechnology bacteria basic structure and general characteristics ecological role economic use diseases medical biotechnology. In classical methodology, two different kinds of stains have been used to identify bacteria. Some general structural features of bacteria springerlink. They lack organelles such as chloroplasts and mitochondria, and they do not have the true nucleus found in eukaryotic cells.
Unlike many organisms,bacteria have no natural death. These groups contain organisms that share common characteristics and traits from other organisms in a different group. Following isolation of bacteria, students characterize the bacteria with household disinfectant products and antibiotics. Gram characteristics of bacteria introduction bacteria are interesting little critters in that they are not easily visualized without some sort of stain. The bacteriophage inject its genetic material into the bacteria. One of the major distinctions between bacterial and eukaryotic genetics stems from the bacteria s lack of membranebound organelles this is true of all prokaryotes. If the pdf does not display below, you may also download it here. That is why in 1 g of a probiotic product from a physical point of view there cannot be so many cells. Pathogenic bacteria may have one or more of the following characteristics.
These proteins assemble, forming structural units called capsomeres. Characteristics of bacteria worksheet flashcards quizlet. Tes global ltd is registered in england company no 02017289 with its registered office at 26 red lion square london wc1r 4hq. The families and genera of the bacteria the first report of. Monera, without cell defined organelles like mitochondria, golgi bodies, endoplasmic reticulum. Qualitative characteristics of lactobacillus bulgaricus and methods of its quantitative determination lactobacillus bulgaricus is the largest in size probiotic bacteria. Discuss the distinguishing characteristics of gram positive and gram negative. The peptidoglycan layer is thick effect of dye do not retain the crystal violet dye, and react only with a counterstain, generally stain pink. A balance develops between persistent infection and protective immunity, resulting in long incubation time and in chronic disease. Bacterial genetics is the subfield of genetics devoted to the study of bacteria. Pdf difference between gram positive and gram negative bacteria.
The bacteria is destroyed due to the attach of a lysogenic bacteriofage. Marcus terentius varro, one of the first theories about microorganisms stated there are bred certain minute creatures. During that period many of the bacteria that cause human disease were identified and characterized. Anatomy of bacteria cell any bacterial cell whether it is a coccus or a bacillus will have some structures common. If you continue browsing the site, you agree to the use of cookies on this website. It can be found in soil, air, water, and living bodies. Antibacterial activity of ethanol and water extracts of leaves of lagerstroemia speciosa l pers.
It is found everywhere on the planet,such as hot spring,deep ocean,deserts and even thrive inside our intestine. Read this article to learn about the characteristics, importance and control of microorganisms such as bacteria, fungi and viruses. Characteristics of bacteria worksheet bacteria are classified into two very different kingdomsarchaebacteria and eubacteria. The study of microorganisms, bacteria, viruses, molds. Bacteria are singlecelled microorganisms with prokaryotic cells, which. General characteristics of bacteria flashcards quizlet.
What are the characteristics common to all bacteria. Bacteria are microscopic organisms that lack a membranebound nucleus and membranebound organelles. They have a different cell structure, but most of them come under two basic shapes like bacillus or cocci. The diversity of bacteria has led this group to be divided into two domains of life, the eubacteria and archaea. Microbiological classification of infectious diseases. Examples of microorganisms include algae, fungi, protozoa, bacteria and. This website and its content is subject to our terms and conditions. In contrast, extracellular bacteria typically cause acute diseases, which develop soon after. Hallmark 6 intracellular bacteria coexist with their cellular habitat for long periods. Differentiate among eukaryotic, prokaryotic, and viral species. Bacteria can survive harsh conditions by forming endospores. Instead, their dna, a double strand that is continuous and circular, is located in a nucleoid. One of the major distinctions between bacterial and eukaryotic genetics stems from the bacterias lack of membranebound organelles this is true of all prokaryotes. Table i shows the general phenotypic classification of bacteria for the.
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