Search results
Results from the WOW.Com Content Network
A prion / ˈ p r iː ɒ n / ⓘ is a misfolded protein that induces misfolding in normal variants of the same protein, leading to cellular death. Prions are responsible for prion diseases, known as transmissible spongiform encephalopathy (TSEs), which are fatal and transmissible neurodegenerative diseases affecting both humans and animals.
The subsequent demonstration that human prion diseases were transmissible reinforced the importance of spongiform change as a diagnostic feature, reflected in the use of the term "spongiform encephalopathy" for this group of disorders. Prions appear to be most infectious when in direct contact with affected tissues.
Others insert additional amino acids into the protein or cause an abnormally short protein to be made. These mutations cause the cell to make prion proteins with an abnormal structure. The abnormal protein PrP Sc accumulates in the brain and destroys nerve cells, which leads to the mental and behavioral features of prion diseases. [citation needed]
Self-replication is a fundamental feature of life. It was proposed that self-replication emerged in the evolution of life when a molecule similar to a double-stranded polynucleotide (possibly like RNA) dissociated into single-stranded polynucleotides and each of these acted as a template for synthesis of a complementary strand producing two double stranded copies. [4]
YouTube Shorts is the short-form section of the online video-sharing platform YouTube. YouTube Shorts focuses on vertical videos that are of less than 180 seconds duration, and has various features for user interaction.
For the virus to reproduce and thereby establish infection, it must enter cells of the host organism and use those cells' materials. To enter the cells, proteins on the surface of the virus interact with proteins of the cell. Attachment, or adsorption, occurs between the viral particle and the host cell membrane.
Furthermore, direct evidence for meiotic recombination, indicative of mating and sexual reproduction, was also found in G. intestinalis. [11] Other protists for which evidence of mating and sexual reproduction has recently been described are parasitic protozoa of the genus Leishmania, [12] Trichomonas vaginalis, [13] and acanthamoeba. [14]
Prion protein, the human gene encoding for the major prion protein PrP (for prion protein) Prion diseases, a group of progressive and invariably fatal symptoms affecting the brain (encephalopathies) and nervous system of many animals; Prion pruritus, an intense itching during the prodromal period of the Creutzfeldt–Jakob disease