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Folded Protein
Protein folding is the physical process by which a protein chain is translated to its native three-dimensional structure, typically a "folded" conformation by which the protein becomes biologically functional. Via an expeditious and reproducible process, a polypeptide folds into its characteristic three-dimensional structure from a random coil. Each protein exists first as an unfolded polypeptide or random coil after being translated from a sequence of mRNA to a linear chain of amino acids. At this stage the polypeptide lacks any stable (long-lasting) three-dimensional structure (the left hand side of the first figure). As the polypeptide chain is being synthesized by a ribosome, the linear chain begins to fold into its three-dimensional structure. Folding of many proteins begins even during translation of the polypeptide chain. Amino acids interact with each other to produce a well-defined three-dimensional structure, the folded protein (the right hand side of the figure), kn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurodegenerative
A neurodegenerative disease is caused by the progressive loss of structure or function of neurons, in the process known as neurodegeneration. Such neuronal damage may ultimately involve cell death. Neurodegenerative diseases include amyotrophic lateral sclerosis, multiple sclerosis, Parkinson's disease, Alzheimer's disease, Huntington's disease, multiple system atrophy, and prion diseases. Neurodegeneration can be found in the brain at many different levels of neuronal circuitry, ranging from molecular to systemic. Because there is no known way to reverse the progressive degeneration of neurons, these diseases are considered to be incurable; however research has shown that the two major contributing factors to neurodegeneration are oxidative stress and inflammation. Biomedical research has revealed many similarities between these diseases at the subcellular level, including atypical protein assemblies (like proteinopathy) and induced cell death. These similarities suggest that the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
In Vitro
''In vitro'' (meaning in glass, or ''in the glass'') studies are performed with microorganisms, cells, or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in biology and its subdisciplines are traditionally done in labware such as test tubes, flasks, Petri dishes, and microtiter plates. Studies conducted using components of an organism that have been isolated from their usual biological surroundings permit a more detailed or more convenient analysis than can be done with whole organisms; however, results obtained from ''in vitro'' experiments may not fully or accurately predict the effects on a whole organism. In contrast to ''in vitro'' experiments, ''in vivo'' studies are those conducted in living organisms, including humans, and whole plants. Definition ''In vitro'' ( la, in glass; often not italicized in English usage) studies are conducted using components of an organism that have been isolated fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proteinopathy
In medicine, proteinopathy (; 'pref''. protein -pathy 'suff''. disease proteinopathies ''pl''.; proteinopathic ''adj''), or proteopathy, protein conformational disorder, or protein misfolding disease refers to a class of diseases in which certain proteins become structurally abnormal, and thereby disrupt the function of cells, tissues and organs of the body. Often the proteins fail to fold into their normal configuration; in this misfolded state, the proteins can become toxic in some way (a toxic gain-of-function) or they can lose their normal function. The proteinopathies include such diseases as Creutzfeldt–Jakob disease and other prion diseases, Alzheimer's disease, Parkinson's disease, amyloidosis, multiple system atrophy, and a wide range of other disorders. The term ''proteopathy'' was first proposed in 2000 by Lary Walker and Harry LeVine. The concept of proteopathy can trace its origins to the mid-19th century, when, in 1854, Rudolf Virchow coined the term amyl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Burn
A burn is an injury to skin, or other tissues, caused by heat, cold, electricity, chemicals, friction, or ultraviolet radiation (like sunburn). Most burns are due to heat from hot liquids (called scalding), solids, or fire. Burns occur mainly in the home or the workplace. In the home, risks are associated with domestic kitchens, including stoves, flames, and hot liquids. In the workplace, risks are associated with fire and chemical and electric burns. Alcoholism and smoking are other risk factors. Burns can also occur as a result of self-harm or violence between people (assault). Burns that affect only the superficial skin layers are known as superficial or first-degree burns. They appear red without blisters and pain typically lasts around three days. When the injury extends into some of the underlying skin layer, it is a partial-thickness or second-degree burn. Blisters are frequently present and they are often very painful. Healing can require up to eight weeks and scarri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cooking
Cooking, cookery, or culinary arts is the art, science and craft of using heat to Outline of food preparation, prepare food for consumption. Cooking techniques and ingredients vary widely, from grilling food over an open fire to using electric stoves, to baking in various types of ovens, reflecting local conditions. Types of cooking also depend on the skill levels and training of the Cook (profession), cooks. Cooking is done both by people in their own dwellings and by professional cooks and chefs in restaurants and other food establishments. Preparing food with heat or fire is an activity unique to humans. Archeological evidence of cooking fires from at least 300,000 years ago exists, but some estimate that humans started cooking up to 2 million years ago. The expansion of agriculture, commerce, trade, and transportation between civilizations in different regions offered cooks many new ingredients. New inventions and technologies, such as the invention of pottery for holding ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Random Coil
In polymer chemistry, a random coil is a conformation of polymers where the monomer subunits are oriented randomly while still being bonded to adjacent units. It is not one specific shape, but a statistical distribution of shapes for all the chains in a population of macromolecules. The conformation's name is derived from the idea that, in the absence of specific, stabilizing interactions, a polymer backbone will "sample" all possible conformations randomly. Many unbranched, linear homopolymers — in solution, or above their melting temperatures — assume (approximate) random coils. Random walk model: The Gaussian chain There are an enormous number of different ways in which a chain can be curled around in a relatively compact shape, like an unraveling ball of twine with much open space, and comparatively few ways it can be more or less stretched out. So, if each conformation has an equal probability or statistical weight, chains are much more likely to be ball-like than ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Denaturation (biochemistry)
In biochemistry, denaturation is a process in which proteins or nucleic acids lose the quaternary structure, tertiary structure, and secondary structure which is present in their native state, by application of some external stress or compound such as a strong acid or base, a concentrated inorganic salt, an organic solvent (e.g., alcohol or chloroform), agitation and radiation or heat. If proteins in a living cell are denatured, this results in disruption of cell activity and possibly cell death. Protein denaturation is also a consequence of cell death. Denatured proteins can exhibit a wide range of characteristics, from conformational change and loss of solubility to aggregation due to the exposure of hydrophobic groups. The loss of solubility as a result of denaturation is called ''coagulation''. Denatured proteins lose their 3D structure and therefore cannot function. Protein folding is key to whether a globular or membrane protein can do its job correctly; it must be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antibodies
An antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shaped protein used by the immune system to identify and neutralize foreign objects such as pathogenic bacteria and viruses. The antibody recognizes a unique molecule of the pathogen, called an antigen. Each tip of the "Y" of an antibody contains a paratope (analogous to a lock) that is specific for one particular epitope (analogous to a key) on an antigen, allowing these two structures to bind together with precision. Using this binding mechanism, an antibody can ''tag'' a microbe or an infected cell for attack by other parts of the immune system, or can neutralize it directly (for example, by blocking a part of a virus that is essential for its invasion). To allow the immune system to recognize millions of different antigens, the antigen-binding sites at both tips of the antibody come in an equally wide variety. In contrast, the remainder of the antibody is relatively constant. It only occurs in a few vari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Immune System
The immune system is a network of biological processes that protects an organism from diseases. It detects and responds to a wide variety of pathogens, from viruses to parasitic worms, as well as cancer cells and objects such as wood splinters, distinguishing them from the organism's own healthy tissue. Many species have two major subsystems of the immune system. The innate immune system provides a preconfigured response to broad groups of situations and stimuli. The adaptive immune system provides a tailored response to each stimulus by learning to recognize molecules it has previously encountered. Both use molecules and cells to perform their functions. Nearly all organisms have some kind of immune system. Bacteria have a rudimentary immune system in the form of enzymes that protect against virus infections. Other basic immune mechanisms evolved in ancient plants and animals and remain in their modern descendants. These mechanisms include phagocytosis, antimicrobial pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Allergy
Allergies, also known as allergic diseases, refer a number of conditions caused by the hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include Allergic rhinitis, hay fever, Food allergy, food allergies, atopic dermatitis, allergic asthma, and anaphylaxis. Symptoms may include allergic conjunctivitis, red eyes, an itchy rash, sneeze, sneezing, coughing, a rhinorrhea, runny nose, shortness of breath, or swelling. Note: food intolerances and food poisoning are separate conditions. Common allergens include pollen and certain foods. Metals and other substances may also cause such problems. Food, insect stings, and medications are common causes of severe reactions. Their development is due to both genetic and environmental factors. The underlying mechanism involves immunoglobulin E antibodies (IgE), part of the body's immune system, binding to an allergen and then to FcεRI, a receptor on mast cells or basophils where it tri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prion
Prions are misfolded proteins that have the ability to transmit their misfolded shape onto normal variants of the same protein. They characterize several fatal and transmissible neurodegenerative diseases in humans and many other animals. It is not known what causes a normal protein to misfold, but the resulting abnormal three-dimensional structure confers infectious properties by collapsing nearby protein molecules into the same shape. The word ''prion'' is derived from the term, "proteinaceous infectious particle". In comparison to all other known infectious agents such as viroids, viruses, bacteria, fungi, and parasites, all of which contain nucleic acids ( DNA, RNA, or both), the hypothesized role of a protein as an infectious agent stands in contrast. Prion isoforms of the prion protein (PrP), whose specific function is uncertain, are hypothesized as the cause of transmissible spongiform encephalopathies (TSEs), including scrapie in sheep, chronic wasting disease (CWD) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
