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== 2024.03.29 ==
<img style="width: 484px; height: 454px;" src=http://Biolecture.org/upload/20240329131251_image.png><br/> full txt link : [https://www.hani.co.kr/arti/society/rights/471412.html https://www.hani.co.kr/arti/society/rights/471412.html]<br/> <br/> <br/>
== 2024.04.05 ==
=== DNA ===
Within eukaryotic cells, DNA is organized into long structures called [https://en.wikipedia.org/wiki/Chromosome chromosomes]. Before typical [https://en.wikipedia.org/wiki/Cell_division cell division], these chromosomes are duplicated in the process of DNA replication, providing a complete set of chromosomes for each daughter cell. [https://en.wikipedia.org/wiki/Eukaryote Eukaryotic organisms] ([https://en.wikipedia.org/wiki/Animal animals], [https://en.wikipedia.org/wiki/Plant plants], [https://en.wikipedia.org/wiki/Fungus fungi] and [https://en.wikipedia.org/wiki/Protist protists]) store most of their DNA inside the [https://en.wikipedia.org/wiki/Cell_nucleus cell nucleus] as [https://en.wikipedia.org/wiki/Nuclear_DNA nuclear DNA], and some in the [https://en.wikipedia.org/wiki/Mitochondrion mitochondria] as [https://en.wikipedia.org/wiki/Mitochondrial_DNA mitochondrial DNA] or in [https://en.wikipedia.org/wiki/Chloroplast chloroplasts] as [https://en.wikipedia.org/wiki/Chloroplast_DNA chloroplast DNA].[https://en.wikipedia.org/wiki/DNA#cite_note-5 <sup>[5</sup>]] In contrast, [https://en.wikipedia.org/wiki/Prokaryote prokaryotes] ([https://en.wikipedia.org/wiki/Bacteria bacteria] and [https://en.wikipedia.org/wiki/Archaea archaea]) store their DNA only in the [https://en.wikipedia.org/wiki/Cytoplasm cytoplasm], in [https://en.wikipedia.org/wiki/Circular_chromosome circular chromosomes]. Within eukaryotic chromosomes, [https://en.wikipedia.org/wiki/Chromatin chromatin] proteins, such as [https://en.wikipedia.org/wiki/Histone histones], compact and organize DNA. These compacting structures guide the interactions between DNA and other proteins, helping control which parts of the DNA are transcribed.<br/> <br/> full text link : [https://en.wikipedia.org/wiki/DNA https://en.wikipedia.org/wiki/DNA]
=== RNA ===
It has become widely accepted in science[https://en.wikipedia.org/wiki/RNA#cite_note-1 <sup>[1</sup>]] that early in the [https://en.wikipedia.org/wiki/History_of_life_on_Earth history of life on Earth], prior to the evolution of DNA and possibly of protein-based [https://en.wikipedia.org/wiki/Enzyme enzymes] as well, an "[https://en.wikipedia.org/wiki/RNA_world RNA world]" existed in which RNA served as both living organisms' storage method for [https://en.wikipedia.org/wiki/Genetic_information genetic information]—a role fulfilled today by DNA, except in the case of [https://en.wikipedia.org/wiki/RNA_virus RNA viruses]—and potentially performed catalytic functions in cells—a function performed today by protein enzymes, with the notable and important exception of the ribosome, which is a [https://en.wikipedia.org/wiki/Ribozyme ribozyme].<br/> <br/> Full text link : [https://en.wikipedia.org/wiki/RNA https://en.wikipedia.org/wiki/RNA]
=== eQTL ===
Mapping eQTLs is done using standard [https://en.wikipedia.org/wiki/QTL QTL] mapping methods that test the linkage between variation in expression and genetic polymorphisms. The only considerable difference is that eQTL studies can involve a million or more expression microtraits. Standard gene mapping software packages can be used, although it is often faster to use custom code such as QTL Reaper or the web-based eQTL mapping system [https://en.wikipedia.org/wiki/GeneNetwork GeneNetwork]. GeneNetwork hosts many large eQTL mapping data sets and provide access to fast algorithms to map single loci and [https://en.wikipedia.org/wiki/Epistasis epistatic] interactions. As is true in all QTL mapping studies, the final steps in defining DNA variants that cause variation in traits are usually difficult and require a second round of experimentation. This is especially the case for trans eQTLs that do not benefit from the strong prior probability that relevant variants are in the immediate vicinity of the parent gene. Statistical, graphical, and bioinformatic methods are used to evaluate positional candidate genes and entire systems of interactions.[https://en.wikipedia.org/wiki/Expression_quantitative_trait_loci#cite_note-Kulp_2006-18 <sup>[18</sup>]][https://en.wikipedia.org/wiki/Expression_quantitative_trait_loci#cite_note-Lee_2009-19 <sup>[19</sup>]] The development of single cell technologies, and parallel advances in statistical methods has made it possible to define even subtle changes in eQTLs as cell-states change.[https://en.wikipedia.org/wiki/Expression_quantitative_trait_loci#cite_note-20 <sup>[20</sup>]][https://en.wikipedia.org/wiki/Expression_quantitative_trait_loci#cite_note-21 <sup>[21</sup>]]
Full text link : [https://en.wikipedia.org/wiki/Expression_quantitative_trait_loci https://en.wikipedia.org/wiki/Expression_quantitative_trait_loci]<br/> == 2024.04.12 == === Proteomics === '''Proteomics''' is the large-scale study of [https://en.wikipedia.org/wiki/Protein proteins].<sup id="cite_ref-pmid9740045_1-0">[https://en.wikipedia.org/wiki/Proteomics#cite_note-pmid9740045-1 [1]]</sup><sup id="cite_ref-pmid10189717_2-0">[https://en.wikipedia.org/wiki/Proteomics#cite_note-pmid10189717-2 [2]]</sup> Proteins are vital parts of living organisms, with many functions such as the formation of structural fibers of [https://en.wikipedia.org/wiki/Muscle_tissue muscle tissue], enzymatic digestion of food, or synthesis and replication of [https://en.wikipedia.org/wiki/DNA DNA]. In addition, other kinds of proteins include [https://en.wikipedia.org/wiki/Antibodies antibodies] that protect an organism from infection, and [https://en.wikipedia.org/wiki/Hormones hormones] that send important signals throughout the body. The [https://en.wikipedia.org/wiki/Proteome proteome] is the entire set of proteins produced or modified by an organism or system. Proteomics enables the identification of ever-increasing numbers of proteins. This varies with time and distinct requirements, or stresses, that a cell or organism undergoes.<sup id="cite_ref-3">[https://en.wikipedia.org/wiki/Proteomics#cite_note-3 [3]]</sup> Proteomics is an interdisciplinary domain that has benefited greatly from the genetic information of various genome projects, including the [https://en.wikipedia.org/wiki/Human_Genome_Project Human Genome Project].<sup id="cite_ref-4">[https://en.wikipedia.org/wiki/Proteomics#cite_note-4 [4]]</sup> It covers the exploration of proteomes from the overall level of protein composition, structure, and activity, and is an important component of [https://en.wikipedia.org/wiki/Functional_genomics functional genomics]. ''Proteomics'' generally denotes the large-scale experimental analysis of proteins and proteomes, but often refers specifically to [https://en.wikipedia.org/wiki/Protein_purification protein purification] and [https://en.wikipedia.org/wiki/Mass_spectrometry mass spectrometry]. Indeed, mass spectrometry is the most powerful method for analysis of proteomes, both in large samples composed of millions of cells<sup id="cite_ref-5">[https://en.wikipedia.org/wiki/Proteomics#cite_note-5 [5]]</sup> and in single cells.<sup id="cite_ref-6">[https://en.wikipedia.org/wiki/Proteomics#cite_note-6 [6]]</sup><sup id="cite_ref-7">[https://en.wikipedia.org/wiki/Proteomics#cite_note-7 [7]]</sup> <br/> <br/> Full text link : [https://en.wikipedia.org/wiki/Proteomics https://en.wikipedia.org/wiki/Proteomics] === Omics === The branches of [https://en.wikipedia.org/wiki/Science science] known informally as '''omics''' are various disciplines in [https://en.wikipedia.org/wiki/Biology biology] whose names end in the suffix ''[https://en.wiktionary.org/wiki/-omics -omics]'', such as [https://en.wikipedia.org/wiki/Genomics genomics], [https://en.wikipedia.org/wiki/Proteomics proteomics], [https://en.wikipedia.org/wiki/Metabolomics metabolomics], [https://en.wikipedia.org/wiki/Metagenomics metagenomics], [https://en.wikipedia.org/wiki/Phenomics phenomics] and [https://en.wikipedia.org/wiki/Transcriptomics transcriptomics]. Omics aims at the collective characterization and quantification of pools of biological molecules that translate into the structure, function, and dynamics of an organism or organisms.<sup id="cite_ref-1">[https://en.wikipedia.org/wiki/Omics#cite_note-1 [1]]</sup> The related suffix '''-ome''' is used to address the objects of study of such fields, such as the [https://en.wikipedia.org/wiki/Genome genome], [https://en.wikipedia.org/wiki/Proteome proteome] or [https://en.wikipedia.org/wiki/Metabolome metabolome] respectively. The suffix ''-ome'' as used in molecular biology refers to a ''totality'' of some sort; it is an example of a "neo-suffix" formed by abstraction from various Greek terms in -ωμα, a sequence that does not form an identifiable suffix in Greek. [https://en.wikipedia.org/wiki/Functional_genomics Functional genomics] aims at identifying the functions of as many genes as possible of a given organism. It combines different -omics techniques such as transcriptomics and proteomics with saturated mutant collections.<sup id="cite_ref-2">[https://en.wikipedia.org/wiki/Omics#cite_note-2 [2]]</sup> <br/> <br/> Full text link : [https://en.wikipedia.org/wiki/Omics https://en.wikipedia.org/wiki/Omics]<br/> <br/> === -ology === An '''ology''' or '''[https://en.wikipedia.org/wiki/-logy -''logy'']''' is a scientific discipline.<br/> === Protein === '''Proteins''' are large [https://en.wikipedia.org/wiki/Biomolecule biomolecules] and [https://en.wikipedia.org/wiki/Macromolecule macromolecules] that comprise one or more long chains of [https://en.wikipedia.org/wiki/Amino_acid amino acid] [https://en.wikipedia.org/wiki/Residue_(biochemistry) residues]. Proteins perform a vast array of functions within organisms, including [https://en.wikipedia.org/wiki/Enzyme_catalysis catalysing metabolic reactions], [https://en.wikipedia.org/wiki/DNA_replication DNA replication], [https://en.wikipedia.org/wiki/Cell_signaling responding to stimuli], providing [https://en.wikipedia.org/wiki/Cytoskeleton structure to cells] and [https://en.wikipedia.org/wiki/Fibrous_protein organisms], and [https://en.wikipedia.org/wiki/Intracellular_transport transporting molecules] from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the [https://en.wikipedia.org/wiki/Nucleic_acid_sequence nucleotide sequence] of their [https://en.wikipedia.org/wiki/Gene genes], and which usually results in [https://en.wikipedia.org/wiki/Protein_folding protein folding] into a specific [https://en.wikipedia.org/wiki/Protein_structure 3D structure] that determines its activity. A linear chain of amino acid residues is called a [https://en.wikipedia.org/wiki/Polypeptide polypeptide]. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called [https://en.wikipedia.org/wiki/Peptide peptides]. The individual amino acid residues are bonded together by [https://en.wikipedia.org/wiki/Peptide_bond peptide bonds] and adjacent amino acid residues. The [https://en.wikipedia.org/wiki/Protein_primary_structure sequence] of amino acid residues in a protein is defined by the [https://en.wikipedia.org/wiki/DNA_sequencing sequence] of a gene, which is encoded in the [https://en.wikipedia.org/wiki/Genetic_code genetic code]. In general, the genetic code specifies 20 standard amino acids; but in certain organisms the genetic code can include [https://en.wikipedia.org/wiki/Selenocysteine selenocysteine] and—in certain [https://en.wikipedia.org/wiki/Archaea archaea]—[https://en.wikipedia.org/wiki/Pyrrolysine pyrrolysine]. Shortly after or even during synthesis, the residues in a protein are often chemically modified by [https://en.wikipedia.org/wiki/Post-translational_modification post-translational modification], which alters the physical and chemical properties, folding, stability, activity, and ultimately, the function of the proteins. Some proteins have non-peptide groups attached, which can be called [https://en.wikipedia.org/wiki/Prosthetic_group prosthetic groups] or [https://en.wikipedia.org/wiki/Cofactor_(biochemistry) cofactors]. Proteins can also work together to achieve a particular function, and they often associate to form stable [https://en.wikipedia.org/wiki/Protein_complex protein complexes]. Once formed, proteins only exist for a certain period and are then [https://en.wikipedia.org/wiki/Proteolysis#Protein_degradation degraded] and recycled by the cell's machinery through the process of [https://en.wikipedia.org/wiki/Protein_turnover protein turnover]. A protein's lifespan is measured in terms of its [https://en.wikipedia.org/wiki/Half-life half-life] and covers a wide range. They can exist for minutes or years with an average lifespan of 1–2 days in mammalian cells. Abnormal or misfolded proteins are degraded more rapidly either due to being targeted for destruction or due to being unstable. Like other biological macromolecules such as [https://en.wikipedia.org/wiki/Polysaccharide polysaccharides] and [https://en.wikipedia.org/wiki/Nucleic_acid nucleic acids], proteins are essential parts of organisms and participate in virtually every process within [https://en.wikipedia.org/wiki/Cell_(biology) cells]. Many proteins are [https://en.wikipedia.org/wiki/Enzyme enzymes] that [https://en.wikipedia.org/wiki/Catalysis catalyse] biochemical reactions and are vital to [https://en.wikipedia.org/wiki/Metabolism metabolism]. Proteins also have structural or mechanical functions, such as [https://en.wikipedia.org/wiki/Actin actin] and [https://en.wikipedia.org/wiki/Myosin myosin] in muscle and the proteins in the [https://en.wikipedia.org/wiki/Cytoskeleton cytoskeleton], which form a system of [https://en.wikipedia.org/wiki/Scaffolding scaffolding] that maintains cell shape. Other proteins are important in cell signaling, [https://en.wikipedia.org/wiki/Antibody immune responses], [https://en.wikipedia.org/wiki/Cell_adhesion cell adhesion], and the [https://en.wikipedia.org/wiki/Cell_cycle cell cycle]. In animals, proteins are needed in the [https://en.wikipedia.org/wiki/Diet_(nutrition) diet] to provide the [https://en.wikipedia.org/wiki/Essential_amino_acid essential amino acids] that cannot be [https://en.wikipedia.org/wiki/Amino_acid_synthesis synthesized]. [https://en.wikipedia.org/wiki/Digestion Digestion] breaks the proteins down for metabolic use. Proteins may be [https://en.wikipedia.org/wiki/Protein_purification purified] from other cellular components using a variety of techniques such as [https://en.wikipedia.org/wiki/Ultracentrifugation ultracentrifugation], [https://en.wikipedia.org/wiki/Precipitation_(chemistry) precipitation], [https://en.wikipedia.org/wiki/Electrophoresis electrophoresis], and [https://en.wikipedia.org/wiki/Chromatography chromatography]; the advent of [https://en.wikipedia.org/wiki/Genetic_engineering genetic engineering] has made possible a number of methods to facilitate purification. Methods commonly used to study protein structure and function include [https://en.wikipedia.org/wiki/Immunohistochemistry immunohistochemistry], [https://en.wikipedia.org/wiki/Site-directed_mutagenesis site-directed mutagenesis], [https://en.wikipedia.org/wiki/X-ray_crystallography X-ray crystallography], [https://en.wikipedia.org/wiki/Nuclear_magnetic_resonance nuclear magnetic resonance] and [https://en.wikipedia.org/wiki/Mass_spectrometry mass spectrometry].<br/> === PPI (Protein-Protein interaction) === '''Protein–protein interactions''' ('''PPIs''') are physical contacts of high specificity established between two or more [https://en.wikipedia.org/wiki/Protein protein] molecules as a result of biochemical events steered by interactions that include [https://en.wikipedia.org/wiki/Electrostatic_forces electrostatic forces], [https://en.wikipedia.org/wiki/Hydrogen_bond hydrogen bonding] and the [https://en.wikipedia.org/wiki/Hydrophobic_effect hydrophobic effect]. Many are physical contacts with molecular associations between chains that occur in a cell or in a living organism in a specific biomolecular context. Proteins rarely act alone as their functions tend to be regulated. Many molecular processes within a cell are carried out by [https://en.wikipedia.org/wiki/Molecular_machine molecular machines] that are built from numerous protein components organized by their PPIs. These physiological interactions make up the so-called [https://en.wikipedia.org/wiki/Interactome interactomics] of the organism, while aberrant PPIs are the basis of multiple aggregation-related diseases, such as [https://en.wikipedia.org/wiki/Creutzfeldt–Jakob_disease Creutzfeldt–Jakob] and [https://en.wikipedia.org/wiki/Alzheimer's_disease Alzheimer's diseases]. PPIs have been studied with [https://en.wikipedia.org/wiki/Methods_to_investigate_protein–protein_interactions many methods] and from different perspectives: [https://en.wikipedia.org/wiki/Biochemistry biochemistry], [https://en.wikipedia.org/wiki/Quantum_chemistry quantum chemistry], [https://en.wikipedia.org/wiki/Molecular_dynamics molecular dynamics], [https://en.wikipedia.org/wiki/Signal_transduction signal transduction], among others.<sup id="cite_ref-Titeca_2019_1-0">[https://en.wikipedia.org/wiki/Protein–protein_interaction#cite_note-Titeca_2019-1 [1]]</sup><sup id="cite_ref-2">[https://en.wikipedia.org/wiki/Protein–protein_interaction#cite_note-2 [2]]</sup><sup id="cite_ref-3">[https://en.wikipedia.org/wiki/Protein–protein_interaction#cite_note-3 [3]]</sup> All this information enables the creation of large protein interaction networks<sup id="cite_ref-Mashaghi.2C_A._2004_113.E2.80.93121_4-0">[https://en.wikipedia.org/wiki/Protein–protein_interaction#cite_note-Mashaghi,_A._2004_113–121-4 [4]]</sup> – similar to [https://en.wikipedia.org/wiki/Metabolic_network metabolic] or [https://en.wikipedia.org/wiki/Genetic_networks genetic/epigenetic networks] – that empower the current knowledge on [https://en.wikipedia.org/wiki/Biochemical_cascade biochemical cascades] and molecular etiology of disease, as well as the discovery of putative protein targets of therapeutic interest.<br/> <br/> full text link : [https://en.wikipedia.org/wiki/Protein–protein_interaction https://en.wikipedia.org/wiki/Protein%E2%80%93protein_interaction] === String === '''in computer sciece''' In [https://en.wikipedia.org/wiki/Computer_programming computer programming], a '''string''' is traditionally a [https://en.wikipedia.org/wiki/Sequence sequence] of [https://en.wikipedia.org/wiki/Character_(computing) characters], either as a [https://en.wikipedia.org/wiki/Literal_(computer_programming) literal constant] or as some kind of [https://en.wikipedia.org/wiki/Variable_(computer_science) variable]. The latter may allow its elements to be [https://en.wikipedia.org/wiki/Immutable_object mutated] and the length changed, or it may be fixed (after creation). A string is generally considered as a [https://en.wikipedia.org/wiki/Data_type data type] and is often implemented as an [https://en.wikipedia.org/wiki/Array_data_structure array data structure] of [https://en.wikipedia.org/wiki/Byte bytes] (or [https://en.wikipedia.org/wiki/Word_(computer_architecture) words]) that stores a sequence of elements, typically characters, using some [https://en.wikipedia.org/wiki/Character_encoding character encoding]. ''String'' may also denote more general [https://en.wikipedia.org/wiki/Array_data_type arrays] or other sequence (or [https://en.wikipedia.org/wiki/List_(abstract_data_type) list]) data types and structures. Depending on the programming language and precise data type used, a [https://en.wikipedia.org/wiki/Variable_(programming) variable] declared to be a string may either cause storage in memory to be statically allocated for a predetermined maximum length or employ [https://en.wikipedia.org/wiki/Dynamic_allocation dynamic allocation] to allow it to hold a variable number of elements. When a string appears literally in [https://en.wikipedia.org/wiki/Source_code source code], it is known as a [https://en.wikipedia.org/wiki/String_literal string literal] or an anonymous string.<sup id="cite_ref-1">[https://en.wikipedia.org/wiki/String_(computer_science)#cite_note-1 [1]]</sup> In [https://en.wikipedia.org/wiki/Formal_language formal languages], which are used in [https://en.wikipedia.org/wiki/Mathematical_logic mathematical logic] and [https://en.wikipedia.org/wiki/Theoretical_computer_science theoretical computer science], a string is a finite sequence of [https://en.wikipedia.org/wiki/Symbol_(formal) symbols] that are chosen from a [https://en.wikipedia.org/wiki/Set_(mathematics) set] called an [https://en.wikipedia.org/wiki/Alphabet_(computer_science) alphabet].<br/> <br/> full text link : [https://en.wikipedia.org/wiki/String_(computer_science) https://en.wikipedia.org/wiki/String_(computer_science)]<br/> <br/> '''in structure'''<br/> '''String''' is a long flexible [https://en.wikipedia.org/wiki/Structure structure] made from [https://en.wikipedia.org/wiki/Fiber fibers] twisted together into a single strand, or from multiple such strands which are in turn twisted together. String is used to tie, bind, or hang other objects. It is also used as a material to make things, such as textiles, and in arts and crafts. String is a simple [https://en.wikipedia.org/wiki/Tool tool], and its use by humans is known to have been developed tens of thousands of years ago.<sup id="cite_ref-Evans_and_Webster_1-0">[https://en.wikipedia.org/wiki/String_(structure)#cite_note-Evans_and_Webster-1 [1]]</sup> In [https://en.wikipedia.org/wiki/Mesoamerica Mesoamerica], for example, string was invented some 20,000 to 30,000 years ago, and was made by twisting plant fibers together.<sup id="cite_ref-Evans_and_Webster_1-1">[https://en.wikipedia.org/wiki/String_(structure)#cite_note-Evans_and_Webster-1 [1]]</sup> String may also be a component in other tools, and in devices as diverse as weapons, musical instruments, and toys.<br/> <br/> full text link : [https://en.wikipedia.org/wiki/String_(structure) https://en.wikipedia.org/wiki/String_(structure)] <br/> <br/> [https://biolecture.org/Main_Page Main Page] » [https://biolecture.org/UNIST_Geromics_course UNIST Geromics course] » [https://biolecture.org/Geromics_Course_Students_Folder_2024 Geromics Course Students Folder 2024] » [https://biolecture.org/HyoungJinChoi_2024_Geromics_Course HyoungJinChoi 2024 Geromics Course] » [https://biolecture.org/Summary_class_Geromics_2024_HyoungJinChoi Summary class Geromics 2024 HyoungJinCho]