The term genome was created in 1920 by Hans Winkler, professor of botany at the University of Hamburg, Germany. The Oxford Dictionary and the Online Etymology Dictionary suggest the name is a blend of the words gene and chromosome. However, see omics for a more thorough discussion. A few related -ome words already existed, such as biome and rhizome, forming a …

A phagemid or phasmid is a DNA-based cloning vector, which has both bacteriophage and plasmid properties. These vectors carry, in addition to the origin of plasmid replication, an origin of replication derived from bacteriophage. Unlike commonly used plasmids, phagemid vectors differ by having the ability to be packaged into the capsid of a bacteriophage, due to their having a …

A mitochondrion (/ ˌ m aɪ t ə ˈ k ɒ n d r i ə n /; pl. mitochondria) is an organelle found in the cells of most Eukaryotes, such as animals, plants and fungi.Mitochondria have a double membrane structure and use aerobic respiration to generate adenosine triphosphate (ATP), which is used throughout the cell as a source of chemical energy. They were discovered by Albert von …

The first hypothesis that tried to explain how prions replicate in a protein-only manner was the heterodimer model. This model assumed that a single PrP Sc molecule binds to a single PrP C molecule and catalyzes its conversion into PrP Sc.The two PrP Sc molecules then come apart and can go on to convert more PrP C.However, a model of prion replication must explain both …

In molecular biology and genetics, translation is the process in which ribosomes in the cytoplasm or endoplasmic reticulum synthesize proteins after the process of transcription of DNA to RNA in the cell's nucleus.The entire process is called gene expression.. In translation, messenger RNA (mRNA) is decoded in a ribosome, outside the nucleus, to produce a specific amino acid chain, …

Traditionally, DNA transposons move around in the genome by a cut and paste method. The system requires a transposase enzyme that catalyzes the movement of the DNA from its current location in the genome and inserts it in a new location. Transposition requires three DNA sites on the transposon: two at each end of the transposon called terminal inverted repeats and one at …

Non-cellular life, or acellular life is life that exists without a cellular structure for at least part of its life cycle. Historically, most (descriptive) definitions of life postulated that an organism must be composed of one or more cells, but this is no longer considered necessary, and modern criteria allow for forms of life based on other structural arrangements.

Bacterial cell division happens through binary fission or sometimes through budding.The divisome is a protein complex in bacteria that is responsible for cell division, constriction of inner and outer membranes during division, and remodeling of the peptidoglycan cell wall at the division site. A tubulin-like protein, FtsZ plays a critical role in formation of a contractile ring for the cell ...

Plasmid-mediated resistance is the transfer of antibiotic resistance genes which are carried on plasmids.The plasmids can be transferred between bacteria within the same species or between different species via conjugation.Plasmids often carry multiple antibiotic resistance genes, contributing to the spread of multidrug-resistance (MDR). Antibiotic resistance mediated by …

A plasmid is a small, extrachromosomal DNA molecule within a cell that is physically separated from chromosomal DNA and can replicate independently. They are most commonly found as small circular, double-stranded DNA molecules in bacteria; however, plasmids are sometimes present in archaea and eukaryotic organisms. In nature, plasmids often carry genes that …

A cosmid is a type of hybrid plasmid that contains a Lambda phage cos sequence. They are often used as a cloning vector in genetic engineering.Cosmids can be used to build genomic libraries.They were first described by Collins and Hohn in 1978. Cosmids can contain 37 to 52 (normally 45) kb of DNA, limits based on the normal bacteriophage packaging size. . They can …

Although ribozymes are quite rare in most cells, their roles are sometimes essential to life. For example, the functional part of the ribosome, the biological machine that translates RNA into proteins, is fundamentally a ribozyme, composed of RNA tertiary structural motifs that are often coordinated to metal ions such as Mg 2+ as cofactors. In a model system, there is no …

Un ser vivo u organismo es un conjunto material de organización compleja, en la que intervienen sistemas de comunicación molecular que lo relacionan internamente y con el medio ambiente en un intercambio de materia y energía de una forma ordenada, teniendo la capacidad de desempeñar las funciones básicas de la vida que son la nutrición, la relación y la …

HeLa (/ ˈ h iː l ɑː /; also Hela or hela) is an immortal cell line used in scientific research. It is the oldest and most commonly used human cell line. The line is derived from cervical cancer cells taken on February 8, 1951, named after Henrietta Lacks, a 31-year-old African-American mother of five, who died of cancer on October 4, 1951. The cell line was found to be remarkably …