What is the general structure of a virus?
Viruses are observed in a wide range of shapes and sizes, but these shapes are constant in a particular viral family. The basic structure of all viruses includes nucleic acid, either DNA (Deoxyribonucleic Acid) or RNA (Ribonucleic Acid) called a genome which is enveloped by a protein coat called a capsid.
What are the basic parts of a virus?
Key Terms
- capsomere: Any of the individual protein subunits of a viral capsid
- capsid: The outer protein shell of a virus.
- icosahedral: of, relating to, or having the shape of an icosahedron
What are the different types of viruses?
- Scientists say climate change and globalization have driven the spread of zoonotic disease.
- Zoonotic diseases are spread from animals to humans, or from humans to animals.
- Coronaviruses, ebola, and mosquito-borne diseases are among those under surveillance.
What are the characteristics of viruses?
- They are acellular, that is, they contain no cytoplasm or cellular organelles.
- They carry out no metabolism on their own and must replicate using the host cell's metabolic machinery. In other words, viruses don't grow and divide. ...
- The vast majority of viruses possess either DNA or RNA but not both.
What are the three basic structures of viruses?
These include: A protective protein shell, or capsid. A nucleic acid genome made of DNA or RNA, tucked inside of the capsid. A layer of membrane called the envelope (some but not all viruses)
What 4 types of viral structures are there?
In general, the shapes of viruses are classified into four groups: filamentous, isometric (or icosahedral), enveloped, and head and tail.
What is the basic structure of a virus and how do they survive?
At the core of a virus particle is the genome, the long molecule made of DNA or RNA that contains the genetic instructions for reproducing the virus. This is wrapped up in a coat made of protein molecules called a capsid, which protects the genetic material.
What is the basic structure of a virus quizlet?
The basic structure of a virus consists of: Genetic information in the form of DNA or RNA enclosed within a protein coat.
What is the structure and function of a virus?
All viruses contain nucleic acid, either DNA or RNA (but not both), and a protein coat, which encases the nucleic acid. Some viruses are also enclosed by an envelope of fat and protein molecules. In its infective form, outside the cell, a virus particle is called a virion.
What are 5 characteristics of viruses?
These are: 1) attachment; 2) penetration; 3) uncoating; 4) replication; 5) assembly; 6)release. As shown in , the virus must first attach itself to the host cell. This is usually accomplished through special glycoprotiens on the exterior of the capsid, envelope or tail.
Which of the following best describes the overall structure of viruses?
True or False: Viruses are capable of evolving. Q. Which of the following best describes the overall structure of viruses? An outer protein coat and nucleic acid within the core.
What are the two essential components of a virus?
The simplest virions consist of two basic components: nucleic acid (single- or double-stranded RNA or DNA) and a protein coat, the capsid, which functions as a shell to protect the viral genome from nucleases and which during infection attaches the virion to specific receptors exposed on the prospective host cell.
What structure can be found in both a virus and a cell?
nucleic acidAccording to the information in the Venn diagram, the only structure or component that a virus and a cell have in common is nucleic acid. The virus lacks all the other cellular structures, and without them, it cannot exist, thrive, and reproduce on its own.
What do all viruses contain?
All true viruses contain nucleic acid—either DNA (deoxyribonucleic acid) or RNA (ribonucleic acid)—and protein. The nucleic acid encodes the genetic information unique for each virus. The infective, extracellular (outside the cell) form of a virus is called the virion.
What is the structure of a virus known as a spike quizlet?
The virus targets epithelial cells in the respiratory system, producing proteins that interfere with their function. viral capsid proteins (spikes) identify specific glycoproteins embedded in the host cell membrane. Drag the flu symptom to its cause.
What is a characteristic of a virus?
They are acellular, that is, they contain no cytoplasm or cellular organelles. They carry out no metabolism on their own and must replicate using the host cell's metabolic machinery. In other words, viruses don't grow and divide. Instead, new viral components are synthesized and assembled within the infected host cell.
What are the four properties that define a virus?
General Properties of VirusesNucleic acid -contains 3-400 genes. Deoxyribonucleic Acid (DNA) -unique features. ... Capsid -The capsid accounts for most of the virion mass. ... Envelope -this is an amorphous structure composed of lipid, protein and carbohydrate which lies to the outside of the capsid. ... Spikes.
What are the types of viruses?
Common Types of Computer VirusesResident Virus. Resident viruses set up shop in your RAM and meddle with your system operations. ... Multipartite Virus. ... Direct Action. ... Browser Hijacker. ... Overwrite Virus. ... Web Scripting Virus. ... File Infector. ... Network Virus.More items...•
How are viruses grouped or classified?
According to the classification, viruses are grouped according to their properties, not the cells they infect. The main criteria were the type of nucleic acid – DNA or RNA.
What is the function of the virion?
The main function of the virion is to deliver its DNA or RNA genome into the host cell so that the genome can be expressed (transcribed and translated) by the host cell. The viral genome, often with associated basic proteins, is packaged inside a symmetric protein capsid.
What is the nucleic acid-associated protein?
The nucleic acid-associated protein, called nucleoprotein, together with the genome, forms the nucleocapsid. In enveloped viruses, the nucleocapsid is surrounded by a lipid bilayer derived from the modified host cell membrane and studded with an outer layer of virus envelope glycoproteins.
Why do viruses exist?
From a selfish standpoint, viruses exist purely to infect unwilling hosts and to utilize the host's machinery for reproduction, so that their babies can infect other hosts.
How small is a virus?
Viruses are so small that you usually need an electron microscope, as opposed to a light microscope you may find in your school lab, to even see one! Basically, the diameters of different viruses fall somewhere in between that of a bacteria on the high end, and that of a ribosome on the low end, which is essentially a range of about 20-300 nanometers in diameter .
What is the study of viruses?
Virology is the study of viruses and the diseases caused by them. A virus is an extremely small infectious agent that is metabolically inert and only replicates in living hosts, while the infective form of a virus that exists outside of its host is known as a virion.
What is the word for a virus that infects bacteria?
Viruses that infect bacteria are called bacteriophages. Viruses can also infect plants. And like a strong poison, nothing is safe from the wrath of a virus, including the strongest, fastest, healthiest human being you can think of. In fact, the word virus actually means 'poison' in Latin.
How do viruses affect the world?
However, the roles viruses play go way beyond their own needs. In fact, they may significantly impact the entire world when they kill off important bacteria in our world's oceans. When the bacteria are killed by these viruses , they, or their nutrients, are eaten as food by bigger organisms, which are in turn, eaten by further larger organisms and so on up the food chain, until the largest of these organisms, namely fish, provide us with nutrients when they end up on our dinner plate.
What is the viral envelope?
In some cases, the viral capsid may also be surrounded by a viral envelope, which is a lipid bilayer derived from the host cell and one that increases the infectivity of a virus. This envelope, sometimes called a coat, can change rapidly in response to many different factors and allows the virus to avoid your immune system if necessary.
What is the outer protective layer of a virion?
Each virion is composed of an outer protective protein coat called a capsid. This capsid is composed of protein subunits, called capsomeres, that are encoded by the nucleic acids that are housed within the capsid itself. The nucleic acid genome can be either DNA or RNA, the organic molecules essential for life.
What determines the type of influenza virus?
The capsid proteins determine the influenza virus type (A, B, C), and the highly variable proteins of the spikes and envelope determine the different strains within each type. The bacteriophage (bacterial virus) shown here has a head shaped like an icosahedron (with 20 sides).
What is the name of the virus that has a protein shell?
See also adenovirus; arbovirus; bacteriophage; picornavirus; plant virus; poxvirus. The influenza virus possesses both a protein shell (capsid) and a lipid and protein envelope. The protein spikes of the envelope facilitate adherence and entry into the host cell.
How do animals respond to viruses?
An animal can respond to a viral infection in various ways, including fever, secretion of interferon, and attack by the immune system. Many human diseases, including influenza, the common cold, and AIDS, as well as many economically important plant and animal diseases, are caused by viruses. Successful vaccines have been developed ...
Is a virus an inactive particle?
Outside of a living cell, a virus is an inactive particle, but within an appropriate host cell it becomes active, capable of taking over the cell’s metabolic machinery for the production of new virus particles (virions).
