A virus is a microscopic parasite that infects cells in biological organisms. Viruses are obligate intracellular parasites; they can reproduce only by invading and controlling other cells as they lack the cellular machinery for self-reproduction. The term virus usually refers to those particles that infect eukaryotes (multi-celled organisms and many single-celled organisms), while the term bacteriophage or phage is used to describe those infecting prokaryotes (bacteria and bacteria-like organisms lacking a nucleus ...

Including:

• Virus - Origins and Beginnings
• Virus - Size structure and anatomy
• Virus - Replication
• Virus - Outline
• Virus - Lifeform debate
• Virus - Study and applications
• Virus - Exploring basic cellular processes
• Virus - Genetic engineering
• Virus - Materials science and nanotechnology
• Virus - Human viral diseases
• Virus - Laboratory diagnosis of pathogenic viruses
• Virus - Prevention and treatment of viral diseases
• Virus - Etymology

Read more here: » Virus: Encyclopedia - Virus

The brief life of an mRNAs begins with transcription and ultimately ends in degradation. During their life, mRNAs may also be processed, edited, and transported prior to translation. Eukaryotic mRNAs often require extensive processing and transport, while prokaryotic mRNAs do not. Messenger RNA - Transcription. Main article: Transcription (genetics) During transcription, RNA polymerase makes a copy of a gene from the DNA to mRNA as needed. This process is similar in eukary ...

See also:

Messenger RNA, Messenger RNA - mRNA life cycle, Messenger RNA - Transcription, Messenger RNA - Eukaryotic pre-mRNA processing, Messenger RNA - Editing, Messenger RNA - Transport, Messenger RNA - Translation, Messenger RNA - Degradation, Messenger RNA - mRNA structure, Messenger RNA - 5' cap, Messenger RNA - Coding regions, Messenger RNA - Untranslated regions, Messenger RNA - 3' polyA tail, Messenger RNA - Anti-sense mRNA

Read more here: » Messenger RNA: Encyclopedia II - Messenger RNA - mRNA life cycle

Because viruses are acellular and do not have their own metabolism, they must utilize the machinery and metabolism of the host for the purpose of self-replication. Before a virus has entered a host cell, it is called a virion — a package of viral genetic material. Virions can be passed from host to host either through direct contact or through a vector, or carrier. Inside the organism, the virus can enter a cell in various ways. Bacteriophages—bacterial viruses—attach to the cell wall surface in specific places. Once attached, e ...

See also:

Virus, Virus - Origins and Beginnings, Virus - Size structure and anatomy, Virus - Replication, Virus - Population growth, Virus - Lifecycle, Virus - Lifeform debate, Virus - Study and applications, Virus - Exploring basic cellular processes, Virus - Viro-therapy, Virus - Genetic engineering, Virus - Materials science and nanotechnology, Virus - Human viral diseases, Virus - Laboratory diagnosis of pathogenic viruses, Virus - Prevention and treatment of viral diseases, Virus - Etymology

Read more here: » Virus: Encyclopedia II - Virus - Replication

Because viruses are acellular and do not have their own metabolism, they must utilize the machinery and metabolism of the host to reproduce. Before a virus has entered a host cell, it is called a virion — a package of viral genetic material. Virions can be passed from host to host either through direct contact or through a vector, or carrier. Inside the organism, the virus can enter a cell in various ways. Bacteriophages—bacterial viruses—attach to the cell wall surface in specific places. Once attached, enzymes make a small hol ...

See also:

Virus, Virus - Origins and Beginnings, Virus - Size structure and anatomy, Virus - Replication, Virus - Outline, Virus - Lifeform debate, Virus - Study and applications, Virus - Exploring basic cellular processes, Virus - Genetic engineering, Virus - Materials science and nanotechnology, Virus - Human viral diseases, Virus - Laboratory diagnosis of pathogenic viruses, Virus - Prevention and treatment of viral diseases, Virus - Etymology

Read more here: » Virus: Encyclopedia II - Virus - Replication

A virus makes use of existing host enzymes and other molecules of a host cell to create more virus particles (virions). Some viruses encode part or all of their own genome replication machinery and are not entirely reliant on host polymerases for replication of their genetic material. Such viruses can be targeted by antiviral drugs that specifically inhibit the virally encoded replicase molecule(s). Viruses rely on host cell ribosomes for the production of viral proteins and utilize several distinct strategies to make the host cell synthesiz ...

See also:

Virus, Virus - Origins and Beginnings, Virus - Size structure and anatomy, Virus - Replication, Virus - Population growth, Virus - Lifecycle, Virus - Lifeform debate, Virus - Study and applications, Virus - Exploring basic cellular processes, Virus - Viro-therapy, Virus - Genetic engineering, Virus - Materials science and nanotechnology, Virus - Human viral diseases, Virus - Laboratory diagnosis of pathogenic viruses, Virus - Prevention and treatment of viral diseases, Virus - Etymology

Read more here: » Virus: Encyclopedia II - Virus - Lifeform debate

Virus - Exploring basic cellular processes. Viruses are important to the study of molecular and cellular biology because they provide simple systems that can be used to manipulate and investigate the functions of cells. The study and use of viruses have provided valuable information about many aspects of cell biology. For example, viruses have further simplified the study of genetics and have helped our understanding of the basic mechanisms of molecular genetics (DNA replication, transcription, RNA processing), Translation (genetics), protein transport, and immunology.

Virus, Virus - Origins and Beginnings, Virus - Size structure and anatomy, Virus - Replication, Virus - Population growth, Virus - Lifecycle, Virus - Lifeform debate, Virus - Study and applications, Virus - Exploring basic cellular processes, Virus - Viro-therapy, Virus - Genetic engineering, Virus - Materials science and nanotechnology, Virus - Human viral diseases, Virus - Laboratory diagnosis of pathogenic viruses, Virus - Prevention and treatment of viral diseases, Virus - Etymology

Read more here: » Virus: Encyclopedia II - Virus - Study and applications

The word is from the Latin virus referring to poison and other noxious things, first used in English in 1392. Virulent, from Latin virulentus "poisonous" dates to 1400. A meaning of "agent that causes infectious disease" is first recorded in 1728, before the discovery of viruses by the Russian biologist Dmitry Ivanovsky in 1892. The adjective viral dates to 1948. Today, Virus is used to describe the biological viruses discussed above and also as a metaphor for other parasitically-reproducing things, such as memes or computer viruses (since 1972). The neologism virion or viron is used to refer to ...

See also:

Virus, Virus - Origins and Beginnings, Virus - Size structure and anatomy, Virus - Replication, Virus - Population growth, Virus - Lifecycle, Virus - Lifeform debate, Virus - Study and applications, Virus - Exploring basic cellular processes, Virus - Viro-therapy, Virus - Genetic engineering, Virus - Materials science and nanotechnology, Virus - Human viral diseases, Virus - Laboratory diagnosis of pathogenic viruses, Virus - Prevention and treatment of viral diseases, Virus - Etymology

Read more here: » Virus: Encyclopedia II - Virus - Etymology

The origins of viruses are not entirely clear and there may not be a single mechanism that can account for all viruses. Some of the smaller viruses that have only a few genes may have originated from host organisms. Their genetic material could have been derived from transferrable elements like plasmids or transposons. Viruses with large genomes may represent extremely reduced microbes which established symbiotic relations with host organisms, allowing the loss of some genes needed for existence independent of a host. Other infectious particles which are even simpler in structure than ...

See also:

Virus, Virus - Origins and Beginnings, Virus - Size structure and anatomy, Virus - Replication, Virus - Population growth, Virus - Lifecycle, Virus - Lifeform debate, Virus - Study and applications, Virus - Exploring basic cellular processes, Virus - Viro-therapy, Virus - Genetic engineering, Virus - Materials science and nanotechnology, Virus - Human viral diseases, Virus - Laboratory diagnosis of pathogenic viruses, Virus - Prevention and treatment of viral diseases, Virus - Etymology

Read more here: » Virus: Encyclopedia II - Virus - Origins and Beginnings

Examples of diseases caused by viruses include the common cold, which is caused by any one of a variety of related viruses; smallpox; AIDS, which is caused by HIV; and cold sores, which are caused by herpes simplex. Other connections are being studied such as the connection of HHV-6 in organic neurological diseases such as Multiple Sclerosis and Chronic Fatigue Syndrome. Recently it has been shown that cervical cancer is caused at least partly by papillomavirus (which causes papillomas, or warts), representing the first significant evidence ...

See also:

Virus, Virus - Origins and Beginnings, Virus - Size structure and anatomy, Virus - Replication, Virus - Population growth, Virus - Lifecycle, Virus - Lifeform debate, Virus - Study and applications, Virus - Exploring basic cellular processes, Virus - Viro-therapy, Virus - Genetic engineering, Virus - Materials science and nanotechnology, Virus - Human viral diseases, Virus - Laboratory diagnosis of pathogenic viruses, Virus - Prevention and treatment of viral diseases, Virus - Etymology

Read more here: » Virus: Encyclopedia II - Virus - Human viral diseases

Examples of diseases caused by viruses include the common cold, which is caused by any one of a variety of related viruses; smallpox; AIDS, which is caused by HIV; and cold sores, which are caused by herpes simplex. Other connections are being studied such as the connection of HHV-6 in organic neurological diseases such as Multiple Sclerosis and Chronic Fatigue Syndrome. Recently it has been shown that cervical cancer is caused at least partly by papillomavirus (which causes papillomas, or warts), representing the first significant evidence ...

See also:

Virus, Virus - Origins and Beginnings, Virus - Size structure and anatomy, Virus - Replication, Virus - Outline, Virus - Lifeform debate, Virus - Study and applications, Virus - Exploring basic cellular processes, Virus - Genetic engineering, Virus - Materials science and nanotechnology, Virus - Human viral diseases, Virus - Laboratory diagnosis of pathogenic viruses, Virus - Prevention and treatment of viral diseases, Virus - Etymology

Read more here: » Virus: Encyclopedia II - Virus - Human viral diseases

The origins of viruses are not entirely clear and there may not be a single mechanism that can account for all viruses. Some of the smaller viruses that have only a few genes may have originated from host organisms. Their genetic material could have been derived from transferrable elements like plasmids or transposons. Viruses with large genomes may represent extremely reduced microbes which established symbiotic relations with host organisms, allowing the loss of some genes needed for existence independent of a host. Other infectious particles which are even simpler in structure than ...

See also:

Virus, Virus - Origins and Beginnings, Virus - Size structure and anatomy, Virus - Replication, Virus - Outline, Virus - Lifeform debate, Virus - Study and applications, Virus - Exploring basic cellular processes, Virus - Genetic engineering, Virus - Materials science and nanotechnology, Virus - Human viral diseases, Virus - Laboratory diagnosis of pathogenic viruses, Virus - Prevention and treatment of viral diseases, Virus - Etymology

Read more here: » Virus: Encyclopedia II - Virus - Origins and Beginnings

A virus makes use of existing host enzymes and other molecules of a host cell to create more virus particles (virions). Some viruses encode part or all of their own genome replication machinery and are not entirely reliant on host polymerases for replication of their genetic material. Such viruses can be targeted by antiviral drugs that specifically inhibit the virally encoded replicase molecule(s). Viruses rely on host cell ribosomes for the production of viral proteins and utilize several distinct strategies to make the host cell synthesiz ...

See also:

Virus, Virus - Origins and Beginnings, Virus - Size structure and anatomy, Virus - Replication, Virus - Outline, Virus - Lifeform debate, Virus - Study and applications, Virus - Exploring basic cellular processes, Virus - Genetic engineering, Virus - Materials science and nanotechnology, Virus - Human viral diseases, Virus - Laboratory diagnosis of pathogenic viruses, Virus - Prevention and treatment of viral diseases, Virus - Etymology

Read more here: » Virus: Encyclopedia II - Virus - Lifeform debate

Virus - Exploring basic cellular processes. Viruses are important to the study of molecular and cellular biology because they provide simple systems that can be used to manipulate and investigate the functions of cells. The study and use of viruses have provided valuable information about many aspects of cell biology. For example, viruses have further simplified the study of genetics and have helped our understanding of the basic mechanisms of molecular genetics (DNA replication, transcription, RNA processing), Translation (genetics), protein transport, and immunology. See also:

Virus, Virus - Origins and Beginnings, Virus - Size structure and anatomy, Virus - Replication, Virus - Outline, Virus - Lifeform debate, Virus - Study and applications, Virus - Exploring basic cellular processes, Virus - Genetic engineering, Virus - Materials science and nanotechnology, Virus - Human viral diseases, Virus - Laboratory diagnosis of pathogenic viruses, Virus - Prevention and treatment of viral diseases, Virus - Etymology

Read more here: » Virus: Encyclopedia II - Virus - Study and applications

The word is from the Latin virus referring to poison and other noxious things, first loaned into English in 1392. Virulent, from Latin virulentus "poisonous" dates to 1400. A meaning of "agent that causes infectious disease" is first recorded in 1728, before the discovery of viruses by the Russian biologist Dmitry Ivanovsky in 1892. The adjective viral dates to 1948. Today, Virus is used to describe the biological viruses discussed above and also as a metaphor for other parasitically-reproducing things, such as memes or computer viruses (since 1972). The neologism virion or viron is used to refer to ...

See also:

Virus, Virus - Origins and Beginnings, Virus - Size structure and anatomy, Virus - Replication, Virus - Outline, Virus - Lifeform debate, Virus - Study and applications, Virus - Exploring basic cellular processes, Virus - Genetic engineering, Virus - Materials science and nanotechnology, Virus - Human viral diseases, Virus - Laboratory diagnosis of pathogenic viruses, Virus - Prevention and treatment of viral diseases, Virus - Etymology

Read more here: » Virus: Encyclopedia II - Virus - Etymology

Messenger RNA - 5' cap. Main article: 5' cap A 5' cap (also called an RNA cap, an RNA 7-methylguanosine cap or an RNA m7G cap) is a modified guanine nucleotide that has been added to the "front" (5' end) of the messenger RNA shortly after the start of transcription. The 5' cap consists of a terminal 7-methylguanosine residue which is linked through a 5'-5'-triphosphate bond to the first transcribed nucleotide. Its presence is critical for recogni ...

See also:

Messenger RNA, Messenger RNA - mRNA life cycle, Messenger RNA - Transcription, Messenger RNA - Eukaryotic pre-mRNA processing, Messenger RNA - Editing, Messenger RNA - Transport, Messenger RNA - Translation, Messenger RNA - Degradation, Messenger RNA - mRNA structure, Messenger RNA - 5' cap, Messenger RNA - Coding regions, Messenger RNA - Untranslated regions, Messenger RNA - 3' polyA tail, Messenger RNA - Anti-sense mRNA

Read more here: » Messenger RNA: Encyclopedia II - Messenger RNA - mRNA structure