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19 Cards in this Set
- Front
- Back
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What is a virus |
An obligate intercellular parasites that infect all forms of life - bacteria, archea, eukarya. It's a non cellular biological entities. |
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Where do viruses replicate? |
They have no metabolic activity outside of the host. They must enter the host cell to replicate |
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In a viruses nucleic acid what can be found? |
Eithe DNA or RNA |
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How do viruses synthesis energy? |
They lack cellular components necessary to harvest energy and synthesize proteins- depend on host cell. |
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What is the size range of viruses? |
30nm- 650nm, various morphological forms. |
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Virus- a broad general term for any aspect of the infectious agent, including - |
The infectious or inactivated virus particle. Viral muscle acid and protein in the infected fluid |
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Viron |
The intact particle in the extra cellular phase which is able to spread to new hots |
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Capsid |
A coat or she'll made of protein subunits - capsomeres |
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Why may a Viron contain enzymes |
For early stages of replication |
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Where do some Virons store viral and host cell components |
Some have a lipoprotein or glycoprotein envelope |
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What's a giant virus? |
Large size and large number of genes including genes for synthesis of nucleotides and amino acids. They challenge the concept of viruses and the evolution of life . |
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The capsid |
All viruses have a shell of one or more proteins that protect the nucleic avid during the extra cellular phase. The small genome of most viruses cant encode a single protein big enough to enclose and protect nucleic acid. A 5 KGB genome requires a 30,000 aa capsid to enclose it but this would require a 99kb genome, just for the capsid! Solution- use multiple copies of the same protein. |
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Subunits or capsomere recognise... |
Each other to form an interface of non covalent interactions. Leads to symmetry because of specific repeated bonding patterns of identical building blocks |
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Helical symmetry |
Subunits or a single polypeptide can interact with each other and nucleic acid to form a ribbon like structure. |
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Icosahedral symmetry |
Here the capsid she'll is made of repeating subunits of viral protein - there may be one kind of subunit or several, according to the virus. |
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Enveloped viruses |
Many animal virus particles are coated in an envelope, acquired as they exit the cell by budding. The envelope contains components of the host cell membrane plus other specialised proteins. |
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What kind of nucleic acid do viral genomes have? |
Only a single type of nucleic acid- DNA or RNA. |
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Viral genome shape |
Linear, circular or segmented - either double stranded or single stranded |
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RNA viruses |
Many animals and human major pathogens. Also important in aquatic ecosystems as pathogens of algae Various replication strategies, depending on wheather there is DNA phase in the cell, or whether single stranded types are + or - |
