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81-419: Chromophobia may also refer to an aversion of use of color in products or design. Within cellular biology , " chromophobic" cells are a classification of cells that do not attract hematoxylin , and is related to chromatolysis . Names exist that mean fear of specific colors such as erythrophobia for the fear of red , xanthophobia for the fear of yellow and leukophobia for the fear of white . A fear of

162-420: A better understanding of the structure and function of cells. Many techniques commonly used to study cell biology are listed below: There are two fundamental classifications of cells: prokaryotic and eukaryotic . Prokaryotic cells are distinguished from eukaryotic cells by the absence of a cell nucleus or other membrane-bound organelle . Prokaryotic cells are much smaller than eukaryotic cells, making them

243-431: A cell binds a molecule that is attached to the membrane of another cell. Endocrine signaling occurs through molecules secreted into the bloodstream. Paracrine signaling uses molecules diffusing between two cells to communicate. Autocrine is a cell sending a signal to itself by secreting a molecule that binds to a receptor on its surface. Forms of communication can be through: Cells are the foundation of all organisms and are

324-461: A cell lineage depends on the maintenance of cell division potential. This potential may be lost in any particular lineage because of cell damage, terminal differentiation as occurs in nerve cells, or programmed cell death ( apoptosis ) during development. Maintenance of cell division potential over successive generations depends on the avoidance and the accurate repair of cellular damage, particularly DNA damage . In sexual organisms, continuity of

405-519: A chain of events that can be easily and definitively observed, depending on the test. More complex serological techniques are known as immunoassays . Using a similar basis as described above, immunoassays can detect or measure antigens from either infectious agents or the proteins generated by an infected host in response to the infection. Polymerase chain reaction (PCR) assays are the most commonly used molecular technique to detect and study microbes. As compared to other methods, sequencing and analysis

486-540: A child against smallpox. The same principles are used for developing vaccines today. Following on from this, in 1857 Louis Pasteur also designed vaccines against several diseases such as anthrax , fowl cholera and rabies as well as pasteurization for food preservation . In 1867 Joseph Lister is considered to be the father of antiseptic surgery. By sterilizing the instruments with diluted carbolic acid and using it to clean wounds, post-operative infections were reduced, making surgery safer for patients. In

567-481: A microbe enters the body is referred to as the portal of entry. These include the respiratory tract , gastrointestinal tract , genitourinary tract , skin , and mucous membranes . The portal of entry for a specific microbe is normally dependent on how it travels from its natural habitat to the host. There are various ways in which disease can be transmitted between individuals. These include: Like other pathogens, viruses use these methods of transmission to enter

648-596: A particular color, although the reaction was not observed in reaction to colored water. The title character in Alfred Hitchcock 's Marnie has an aversion to the color red caused by a trauma during her childhood which Hitchcock presents through expressionistic techniques, such as a wash of red coloring a close up of Marnie. The term colorphobia can also be used refer to its literal etymological origin to refer to an apprehension towards image processing on one's vision and its visual perceptual property. However,

729-421: A potential solution to increasing antimicrobial resistance. Bacteriophages , viruses that only infect bacteria, can specifically target the bacteria of interest and inject their genome. This process makes the bacteria halt its own production to make more phages, and this continues until the bacteria lyses itself and releases the phages into the surrounding environment. Phage therapy does not kill microbiota since it

810-512: A potential strategy for the prevention and treatment of various disorders. Many of these disorders are prevented or improved by consuming polyphenol in the meal. As a result, natural compounds with the ability to modify the autophagy mechanism are seen as a potential therapeutic option. The creation of the double membrane (phagophore), which would be known as nucleation, is the first step in macro-autophagy. The phagophore approach indicates dysregulated polypeptides or defective organelles that come from

891-489: A specific way, aiding in its identification. Serological methods are highly sensitive, specific and often extremely rapid laboratory tests used to identify different types of microorganisms. The tests are based upon the ability of an antibody to bind specifically to an antigen . The antigen (usually a protein or carbohydrate made by an infectious agent) is bound by the antibody, allowing this type of test to be used for organisms other than bacteria. This binding then sets off

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972-399: A stable environment from which the bacteria can disperse and infect other parts of the host. Additionally, the extracellular matrix and dense outer layer of bacterial cells can protect the inner bacteria cells from antimicrobial drugs. Phage therapy is a technique that was discovered before antibiotics, but fell to the wayside as antibiotics became predominate. It is now being considered as

1053-452: A study, hatchling loggerhead sea turtles were found to have an aversion to lights in the yellow wave spectrum which is thought to be a characteristic that helps orient themselves toward the ocean. The Mediterranean sand smelt , Atherina hepsetus , has shown an aversion to red objects placed next to a tank while it will investigate objects of other colors. In other experiments, geese have been conditioned to have adverse reactions to foods of

1134-412: A thin cross-section of the cell of interest, and it then redirects the electrons onto a fluorescent screen. This method is useful for looking at the inside of cells, and the structures within, especially cell walls and membranes. Scanning electron microscopy reads the electrons that are reflected off the surface of the cells. A 3-dimensional image is then made which shows the size and exterior structure of

1215-586: A treatment can be devised. Other tasks may include the identification of potential health risks to the community or monitoring the evolution of potentially virulent or resistant strains of microbes, educating the community and assisting in the design of health practices. They may also assist in preventing or controlling epidemics and outbreaks of disease. Not all medical microbiologists study microbial pathology ; some study common, non-pathogenic species to determine whether their properties can be used to develop antibiotics or other treatment methods. Epidemiology ,

1296-441: A virus in cells of the host are crucial for its survival. For example, some diseases such as measles employ a strategy whereby it must spread to a series of hosts. In these forms of viral infection, the illness is often treated by the body's own immune response , and therefore the virus is required to disperse to new hosts before it is destroyed by immunological resistance or host death. In contrast, some infectious agents such as

1377-431: A σ protein that assists only with initiation. For instance, in a process termed conjugation , the fertility factor allows the bacteria to possess a pilus which allows it to transmit DNA to another bacteria which lacks the F factor, permitting the transmittance of resistance allowing it to survive in certain environments. Eukaryotic cells are composed of the following organelles: Eukaryotic cells may also be composed of

1458-463: Is applied to medicine , is a branch of medical science concerned with the prevention, diagnosis and treatment of infectious diseases . In addition, this field of science studies various clinical applications of microbes for the improvement of health. There are four kinds of microorganisms that cause infectious disease: bacteria , fungi , parasites and viruses , and one type of infectious protein called prion . A medical microbiologist studies

1539-444: Is a fluid continuum between public health microbiology and clinical microbiology , just as the state of the art in clinical laboratories depends on continual improvements in academic medicine and research laboratories . In 1676, Anton van Leeuwenhoek observed bacteria and other microorganisms, using a single-lens microscope of his own design. In 1796, Edward Jenner developed a method using cowpox to successfully immunize

1620-722: Is a self-degradative mechanism that regulates energy sources during growth and reaction to dietary stress. Autophagy also cleans up after itself, clearing aggregated proteins, cleaning damaged structures including mitochondria and endoplasmic reticulum and eradicating intracellular infections. Additionally, autophagy has antiviral and antibacterial roles within the cell, and it is involved at the beginning of distinctive and adaptive immune responses to viral and bacterial contamination. Some viruses include virulence proteins that prevent autophagy, while others utilize autophagy elements for intracellular development or cellular splitting. Macro autophagy, micro autophagy, and chaperon-mediated autophagy are

1701-575: Is also known as the S-phase. During mitosis, which is also known as the M-phase, the segregation of the chromosomes occur. DNA, like every other molecule, is capable of undergoing a wide range of chemical reactions. Modifications in DNA's sequence, on the other hand, have a considerably bigger impact than modifications in other cellular constituents like RNAs or proteins because DNA acts as a permanent copy of

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1782-523: Is an increasingly problematic issue that leads to millions of deaths every year. Whilst drug resistance typically involves microbes chemically inactivating an antimicrobial drug or a cell mechanically stopping the uptake of a drug, another form of drug resistance can arise from the formation of biofilms . Some bacteria are able to form biofilms by adhering to surfaces on implanted devices such as catheters and prostheses and creating an extracellular matrix for other cells to adhere to. This provides them with

1863-829: Is causing the infectious disease and thus what possible methods of treatment could be used. This technique is the current standard for detecting viral infections such as AIDS and hepatitis . Once an infection has been diagnosed and identified, suitable treatment options must be assessed by the physician and consulting medical microbiologists. Some infections can be dealt with by the body's own immune system , but more serious infections are treated with antimicrobial drugs. Bacterial infections are treated with antibacterials (often called antibiotics) whereas fungal and viral infections are treated with antifungals and antivirals respectively. A broad class of drugs known as antiparasitics are used to treat parasitic diseases . Medical microbiologists often make treatment recommendations to

1944-519: Is controlled by the temporal activation of Cdks, which is governed by cyclin partner interaction, phosphorylation by particular protein kinases, and de-phosphorylation by Cdc25 family phosphatases. In response to DNA damage, a cell's DNA repair reaction is a cascade of signaling pathways that leads to checkpoint engagement, regulates, the repairing mechanism in DNA, cell cycle alterations, and apoptosis. Numerous biochemical structures, as well as processes that detect damage in DNA, are ATM and ATR, which induce

2025-433: Is definitive, reliable, accurate, and fast. Today, quantitative PCR is the primary technique used, as this method provides faster data compared to a standard PCR assay. For instance, traditional PCR techniques require the use of gel electrophoresis to visualize amplified DNA molecules after the reaction has finished. quantitative PCR does not require this, as the detection system uses fluorescence and probes to detect

2106-424: Is generally used on samples of free cells or tissue fragments, in contrast to the pathology branch of histopathology , which studies whole tissues. Cytopathology is commonly used to investigate diseases involving a wide range of body sites, often to aid in the diagnosis of cancer but also in the diagnosis of some infectious diseases and other inflammatory conditions. For example, a common application of cytopathology

2187-399: Is simply the exact opposite of respiration as it ultimately produces molecules of glucose. Cell signaling or cell communication is important for cell regulation and for cells to process information from the environment and respond accordingly. Signaling can occur through direct cell contact or endocrine , paracrine , and autocrine signaling . Direct cell-cell contact is when a receptor on

2268-458: Is specific, and it can help those with antibiotic allergies. Some drawbacks are that it is a time-intensive process since the specific bacterium needs to be identified. It also does not currently have the body of research supporting its effects and safety that antibiotics do. Bacteria can also eventually become resistant, through systems like CRISPR/Cas9 system. Many clinical trials have been promising though, showing that it could potentially help with

2349-547: Is strongly linked to the cell mitochondrial channel's ongoing reconfiguration through a range of mechanisms known as mitochondrial membrane dynamics, including endomembrane fusion and fragmentation (separation) and ultrastructural membrane remodeling. As a result, mitochondrial dynamics regulate and frequently choreograph not only metabolic but also complicated cell signaling processes such as cell pluripotent stem cells, proliferation, maturation, aging, and mortality. Mutually, post-translational alterations of mitochondrial apparatus and

2430-468: Is the Gram stain . In 1884 Hans Christian Gram developed the method of staining bacteria to make them more visible and differentiated under a microscope. This technique is widely used today. In 1910 Paul Ehrlich tested multiple combinations of arsenic based chemicals on infected rabbits with syphilis . Ehrlich then found that arsphenamine was found effective against syphilis spirochetes. The arsphenamines

2511-713: Is the Pap smear , a screening test used to detect cervical cancer , and precancerous cervical lesions that may lead to cervical cancer. The cell cycle is composed of a number of well-ordered, consecutive stages that result in cellular division. The fact that cells do not begin the next stage until the last one is finished, is a significant element of cell cycle regulation. Cell cycle checkpoints are characteristics that constitute an excellent monitoring strategy for accurate cell cycle and divisions. Cdks, associated cyclin counterparts, protein kinases, and phosphatases regulate cell growth and division from one stage to another. The cell cycle

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2592-514: Is the cell growth phase – makes up approximately 95% of the cycle. The proliferation of cells is instigated by progenitors. All cells start out in an identical form and can essentially become any type of cells. Cell signaling such as induction can influence nearby cells to determinate the type of cell it will become. Moreover, this allows cells of the same type to aggregate and form tissues, then organs, and ultimately systems. The G1, G2, and S phase (DNA replication, damage and repair) are considered to be

2673-414: Is vital for upholding the correct cellular balance. Autophagy instability leads to a variety of illness symptoms, including inflammation, biochemical disturbances, aging, and neurodegenerative, due to its involvement in controlling cell integrity. The modification of the autophagy-lysosomal networks is a typical hallmark of many neurological and muscular illnesses. As a result, autophagy has been identified as

2754-497: The Feline leukemia virus , are able to withstand immune responses and are capable of achieving long-term residence within an individual host, whilst also retaining the ability to spread into successive hosts. Identification of an infectious agent for a minor illness can be as simple as clinical presentation; such as gastrointestinal disease and skin infections. In order to make an educated estimate as to which microbe could be causing

2835-489: The germline depends on the effectiveness of processes for avoiding DNA damage and repairing those DNA damages that do occur. Sexual processes in eukaryotes , as well as in prokaryotes , provide an opportunity for effective repair of DNA damages in the germ line by homologous recombination . The cell cycle is a four-stage process that a cell goes through as it develops and divides. It includes Gap 1 (G1), synthesis (S), Gap 2 (G2), and mitosis (M). The cell either restarts

2916-450: The sulfa drug . DNA sequencing , a method developed by Walter Gilbert and Frederick Sanger in 1977, caused a rapid change the development of vaccines , medical treatments and diagnostic methods. Some of these include synthetic insulin which was produced in 1979 using recombinant DNA and the first genetically engineered vaccine was created in 1986 for hepatitis B . In 1995 a team at The Institute for Genomic Research sequenced

2997-478: The DNA molecules as they are being amplified. In addition to this, quantitative PCR also removes the risk of contamination that can occur during standard PCR procedures (carrying over PCR product into subsequent PCRs). Another advantage of using PCR to detect and study microbes is that the DNA sequences of newly discovered infectious microbes or strains can be compared to those already listed in databases, which in turn helps to increase understanding of which organism

3078-422: The DNA repair checkpoints The cell cycle is a sequence of activities in which cell organelles are duplicated and subsequently separated into daughter cells with precision. There are major events that happen during a cell cycle. The processes that happen in the cell cycle include cell development, replication and segregation of chromosomes.  The cell cycle checkpoints are surveillance systems that keep track of

3159-512: The OMM connects to other cellular organelles, such as the endoplasmic reticulum (ER), lysosomes, endosomes, and the plasma membrane. Mitochondria play a wide range of roles in cell biology, which is reflected in their morphological diversity. Ever since the beginning of the mitochondrial study, it has been well documented that mitochondria can have a variety of forms, with both their general and ultra-structural morphology varying greatly among cells, during

3240-452: The antimicrobial resistance problem. It can also be used in conjunction with antibiotics for a cumulative effect. Medical microbiology is not only about diagnosing and treating disease, it also involves the study of beneficial microbes. Microbes have been shown to be helpful in combating infectious disease and promoting health. Treatments can be developed from microbes, as demonstrated by Alexander Fleming's discovery of penicillin as well as

3321-478: The body, but viruses differ in that they must also enter into the host's actual cells. Once the virus has gained access to the host's cells, the virus' genetic material ( RNA or DNA ) must be introduced to the cell . Replication between viruses is greatly varied and depends on the type of genes involved in them. Most DNA viruses assemble in the nucleus while most RNA viruses develop solely in cytoplasm. The mechanisms for infection, proliferation, and persistence of

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3402-441: The cell cycle's integrity, accuracy, and chronology. Each checkpoint serves as an alternative cell cycle endpoint, wherein the cell's parameters are examined and only when desirable characteristics are fulfilled does the cell cycle advance through the distinct steps. The cell cycle's goal is to precisely copy each organism's DNA and afterwards equally split the cell and its components between the two new cells. Four main stages occur in

3483-449: The cell cycle, and in response to metabolic or cellular cues. Mitochondria can exist as independent organelles or as part of larger systems; they can also be unequally distributed in the cytosol through regulated mitochondrial transport and placement to meet the cell's localized energy requirements. Mitochondrial dynamics refers to the adaptive and variable aspect of mitochondria, including their shape and subcellular distribution. Autophagy

3564-502: The cell genome. When erroneous nucleotides are incorporated during DNA replication, mutations can occur. The majority of DNA damage is fixed by removing the defective bases and then re-synthesizing the excised area. On the other hand, some DNA lesions can be mended by reversing the damage, which may be a more effective method of coping with common types of DNA damage. Only a few forms of DNA damage are mended in this fashion, including pyrimidine dimers caused by ultraviolet (UV) light changed by

3645-455: The cell has completed its growth process and if it is found to be damaged or altered, it undergoes cell death, either by apoptosis or necrosis , to eliminate the threat it can cause to the organism's survival. The ancestry of each present day cell presumably traces back, in an unbroken lineage for over 3 billion years to the origin of life . It is not actually cells that are immortal but multi-generational cell lineages. The immortality of

3726-419: The cell membrane, Golgi apparatus, endoplasmic reticulum, and mitochondria. With the conclusion of the autophagocyte, the phagophore's enlargement comes to an end. The auto-phagosome combines with the lysosomal vesicles to formulate an auto-lysosome that degrades the encapsulated substances, referred to as phagocytosis. Medical microbiology Medical microbiology , the large subset of microbiology that

3807-588: The cell theory, adding that all cells come from the division of pre-existing cells. Viruses are not considered in cell biology – they lack the characteristics of a living cell and instead are studied in the microbiology subclass of virology . Cell biology research looks at different ways to culture and manipulate cells outside of a living body to further research in human anatomy and physiology , and to derive medications. The techniques by which cells are studied have evolved. Due to advancements in microscopy, techniques and technology have allowed scientists to hold

3888-465: The cells. Both techniques help give more detailed information about the structure of microbes. This makes it useful in many medical fields, such as diagnostics and biopsies of many body parts, hygiene, and virology. They provide critical information about the structure of pathogens, which allow physicians to treat them with more knowledge. Fast and relatively simple biochemical tests can be used to identify infectious agents. For bacterial identification,

3969-608: The characteristics of pathogens , their modes of transmission, mechanisms of infection and growth. The academic qualification as a clinical/Medical Microbiologist in a hospital or medical research centre generally requires a Bachelors degree while in some countries a Masters in Microbiology along with Ph.D. in any of the life-sciences (Biochem, Micro, Biotech, Genetics, etc.). Medical microbiologists often serve as consultants for physicians , providing identification of pathogens and suggesting treatment options. Using this information,

4050-474: The color red may be associated with a fear of blood. In his book Chromophobia published in 2000, David Batchelor says that in Western culture, color has often been treated as corrupting, foreign or superficial. Michael Taussig states that the cultural aversion to color can be traced back a thousand years, with Batchelor stating that it can be traced back to Aristotle 's privileging of line over color. In

4131-414: The color white with chastity and are opposed to or fear chastity. In Paul Beatty 's novel Slumberland , leukophobia refers to racism. Cellular biology Cell biology (also cellular biology or cytology ) is a branch of biology that studies the structure , function , and behavior of cells . All living organisms are made of cells. A cell is the basic unit of life that is responsible for

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4212-420: The components of cells and how cells work is fundamental to all biological sciences while also being essential for research in biomedical fields such as cancer , and other diseases. Research in cell biology is interconnected to other fields such as genetics , molecular genetics , molecular biology , medical microbiology , immunology , and cytochemistry . Cells were first seen in 17th-century Europe with

4293-421: The cycle from G1 or leaves the cycle through G0 after completing the cycle. The cell can progress from G0 through terminal differentiation. Finally, the interphase refers to the phases of the cell cycle that occur between one mitosis and the next, and includes G1, S, and G2. Thus, the phases are: The scientific branch that studies and diagnoses diseases on the cellular level is called cytopathology . Cytopathology

4374-509: The development of transmembrane contact sites among mitochondria and other structures, which both have the potential to link signals from diverse routes that affect mitochondrial membrane dynamics substantially, Mitochondria are wrapped by two membranes: an inner mitochondrial membrane (IMM) and an outer mitochondrial membrane (OMM), each with a distinctive function and structure, which parallels their dual role as cellular powerhouses and signaling organelles. The inner mitochondrial membrane divides

4455-616: The disease, epidemiological factors need to be considered; such as the patient's likelihood of exposure to the suspected organism and the presence and prevalence of a microbial strain in a community. Diagnosis of infectious disease is nearly always initiated by consulting the patient's medical history and conducting a physical examination. More detailed identification techniques involve microbial culture , microscopy , biochemical tests and genotyping . Other less common techniques (such as X-rays , CAT scans , PET scans or NMR ) are used to produce images of internal abnormalities resulting from

4536-429: The effectiveness of certain antimicrobial drugs when making recommendations. Additionally, strains of an organism may be resistant to a certain drug or class of drug, even when it is typically effective against the species. These strains, termed resistant strains, present a serious public health concern of growing importance to the medical industry as the spread of antibiotic resistance worsens. Antimicrobial resistance

4617-461: The eukaryotes. In G1, the cell is usually active and continues to grow rapidly, while in G2, the cell growth continues while protein molecules become ready for separation. These are not dormant times; they are when cells gain mass, integrate growth factor receptors, establish a replicated genome, and prepare for chromosome segregation. DNA replication is restricted to a separate Synthesis in eukaryotes, which

4698-595: The first bacterial genome ; Haemophilus influenzae . A few months later, the first eukaryotic genome was completed. This would prove invaluable for diagnostic techniques. In 2007, a team at the Danish food company Danisco, were able to identify the purpose of the CRIPR-Cas systems as adaptive immunity to phages. The system was then quickly found to be able to help in genome editing through its ability to generate double strand breaks. A patient with sickle cell disease

4779-435: The following molecular components: Cell metabolism is necessary for the production of energy for the cell and therefore its survival and includes many pathways and also sustaining the main cell organelles such as the nucleus, the mitochondria, the cell membrane etc. For cellular respiration , once glucose is available, glycolysis occurs within the cytosol of the cell to produce pyruvate. Pyruvate undergoes decarboxylation using

4860-419: The fundamental units of life. The growth and development of cells are essential for the maintenance of the host and survival of the organism. For this process, the cell goes through the steps of the cell cycle and development which involves cell growth, DNA replication , cell division , regeneration, and cell death . The cell cycle is divided into four distinct phases : G1, S, G2, and M. The G phase – which

4941-426: The growth of an infectious agent. Microbiological culture is the primary method used for isolating infectious disease for study in the laboratory. Tissue or fluid samples are tested for the presence of a specific pathogen , which is determined by growth in a selective or differential medium . The 3 main types of media used for testing are: Culture techniques will often use a microscopic examination to help in

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5022-624: The identification of the microbe. Instruments such as compound light microscopes can be used to assess critical aspects of the organism. This can be performed immediately after the sample is taken from the patient and is used in conjunction with biochemical staining techniques, allowing for resolution of cellular features. Electron microscopes and fluorescence microscopes are also used for observing microbes in greater detail for research. The two main types of electron microscopy are scanning electron microscopy and transmission electron microscopy. Transmission electron microscopy passes electrons through

5103-538: The insertion of methyl or ethyl groups at the purine ring's O6 position. Mitochondria are commonly referred to as the cell's "powerhouses" because of their capacity to effectively produce ATP which is essential to maintain cellular homeostasis and metabolism. Moreover, researchers have gained a better knowledge of mitochondria's significance in cell biology because of the discovery of cell signaling pathways by mitochondria which are crucial platforms for cell function regulation such as apoptosis. Its physiological adaptability

5184-481: The interphase portion of the cycle, while the M phase ( mitosis ) is the cell division portion of the cycle. Mitosis is composed of many stages which include, prophase, metaphase, anaphase, telophase, and cytokinesis, respectively. The ultimate result of mitosis is the formation of two identical daughter cells. The cell cycle is regulated in cell cycle checkpoints , by a series of signaling factors and complexes such as cyclins, cyclin-dependent kinase , and p53 . When

5265-471: The invention of the compound microscope . In 1665, Robert Hooke referred to the building blocks of all living organisms as "cells" (published in Micrographia ) after looking at a piece of cork and observing a structure reminiscent of a monastic cell ; however, the cells were dead. They gave no indication to the actual overall components of a cell. A few years later, in 1674, Anton Van Leeuwenhoek

5346-631: The living and functioning of organisms. Cell biology is the study of the structural and functional units of cells. Cell biology encompasses both prokaryotic and eukaryotic cells and has many subtopics which may include the study of cell metabolism , cell communication , cell cycle , biochemistry , and cell composition . The study of cells is performed using several microscopy techniques, cell culture , and cell fractionation . These have allowed for and are currently being used for discoveries and research pertaining to how cells function, ultimately giving insight into understanding larger organisms. Knowing

5427-449: The lysosomal membrane to enclose the cytosol or organelles. The chaperone-mediated autophagy (CMA) protein quality assurance by digesting oxidized and altered proteins under stressful circumstances and supplying amino acids through protein denaturation. Autophagy is the primary intrinsic degradative system for peptides, fats, carbohydrates, and other cellular structures. In both physiologic and stressful situations, this cellular progression

5508-486: The mitochondrial lumen into two parts: the inner border membrane, which runs parallel to the OMM, and the cristae, which are deeply twisted, multinucleated invaginations that give room for surface area enlargement and house the mitochondrial respiration apparatus. The outer mitochondrial membrane, on the other hand, is soft and permeable. It, therefore, acts as a foundation for cell signaling pathways to congregate, be deciphered, and be transported into mitochondria. Furthermore,

5589-402: The most prominent type, have several different shapes , although most are spherical or rod-shaped . Bacteria can be classed as either gram-positive or gram-negative depending on the cell wall composition. Gram-positive bacteria have a thicker peptidoglycan layer than gram-negative bacteria. Bacterial structural features include a flagellum that helps the cell to move, ribosomes for

5670-468: The multi-enzyme complex to form acetyl coA which can readily be used in the TCA cycle to produce NADH and FADH 2 . These products are involved in the electron transport chain to ultimately form a proton gradient across the inner mitochondrial membrane. This gradient can then drive the production of ATP and H 2 O during oxidative phosphorylation . Metabolism in plant cells includes photosynthesis which

5751-472: The patient's physician based on the strain of microbe and its antibiotic resistances , the site of infection, the potential toxicity of antimicrobial drugs and any drug allergies the patient has. In addition to drugs being specific to a certain kind of organism (bacteria, fungi, etc.), some drugs are specific to a certain genus or species of organism, and will not work on other organisms. Because of this specificity, medical microbiologists must consider

5832-478: The smallest form of life. Prokaryotic cells include Bacteria and Archaea , and lack an enclosed cell nucleus.  Eukaryotic cells are found in plants, animals, fungi, and protists. They range from 10 to 100 μm in diameter, and their DNA is contained within a membrane-bound nucleus. Eukaryotes are organisms containing eukaryotic cells. The four eukaryotic kingdoms are Animalia, Plantae, Fungi, and Protista. They both reproduce through binary fission . Bacteria,

5913-509: The study of the patterns, causes, and effects of health and disease conditions in populations, is an important part of medical microbiology, although the clinical aspect of the field primarily focuses on the presence and growth of microbial infections in individuals, their effects on the human body, and the methods of treating those infections. In this respect the entire field, as an applied science, can be conceptually subdivided into academic and clinical sub-specialties, although in reality there

5994-423: The term's association with a racial component has been used by public figures such as Frederick Douglass . Leukophobia often takes the form of a fixation on pale skin. Those with the phobia may make implausible assumptions such as paleness necessarily representing ill health or a ghost . In other cases, leukophobia is directed more towards the symbolic meaning of whiteness, for instance in individuals who associate

6075-430: The three basic types of autophagy. When macro autophagy is triggered, an exclusion membrane incorporates a section of the cytoplasm, generating the autophagosome, a distinctive double-membraned organelle. The autophagosome then joins the lysosome to create an autolysosome, with lysosomal enzymes degrading the components. In micro autophagy, the lysosome or vacuole engulfs a piece of the cytoplasm by invaginating or protruding

6156-434: The translation of RNA to protein, and a nucleoid that holds all the genetic material in a circular structure. There are many processes that occur in prokaryotic cells that allow them to survive. In prokaryotes, mRNA synthesis is initiated at a promoter sequence on the DNA template comprising two consensus sequences that recruit RNA polymerase. The prokaryotic polymerase consists of a core enzyme of four protein subunits and

6237-581: The use of metabolic or enzymatic characteristics are common due to their ability to ferment carbohydrates in patterns characteristic of their genus and species . Acids, alcohols and gases are usually detected in these tests when bacteria are grown in selective liquid or solid media , as mentioned above. In order to perform these tests en masse, automated machines are used. These machines perform multiple biochemical tests simultaneously, using cards with several wells containing different dehydrated chemicals. The microbe of interest will react with each chemical in

6318-479: The years between 1876 and 1884 Robert Koch provided much insight into infectious diseases. He was one of the first scientists to focus on the isolation of bacteria in pure culture . This gave rise to the germ theory , a certain microorganism being responsible for a certain disease. He developed a series of criteria around this that have become known as the Koch's postulates . A major milestone in medical microbiology

6399-484: Was the first person to be treated for a genetic disorder with CRISPR in July 2019. Bacterial Viral Parasitic Fungal Infections may be caused by bacteria , viruses , fungi , and parasites . The pathogen that causes the disease may be exogenous (acquired from an external source; environmental, animal or other people, e.g. Influenza ) or endogenous (from normal flora e.g. Candidiasis ). The site at which

6480-533: Was the first to analyze live cells in his examination of algae . Many years later, in 1831, Robert Brown discovered the nucleus . All of this preceded the cell theory which states that all living things are made up of cells and that cells are organisms' functional and structural units. This was ultimately concluded by plant scientist Matthias Schleiden and animal scientist Theodor Schwann in 1838, who viewed live cells in plant and animal tissue, respectively. 19 years later, Rudolf Virchow further contributed to

6561-462: Was then made available in 1910, known as Salvarsan . In 1929 Alexander Fleming developed one of the most commonly used antibiotic substances both at the time and now: penicillin . In 1939 Gerhard Domagk found Prontosil red protected mice from pathogenic streptococci and staphylococci without toxicity. Domagk received the Nobel Prize in physiology, or medicine, for the discovery of

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