Virus: Shapes and structure, life cycle - Sideversjonshistorikk

Elisaari: /* Life cycle of phages */

2009-04-12T14:25:23Z

Life cycle of phages

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 One of the variations from this simplified description is the reproductive cycle of phages, bacterial viruses. The viral genome can reproduce by two alternative mechanisms: the lytic cycle and the lysogenic cycle.The lytic cycle corresponds to the cycle described above.
-But after having entered the host cell, the viral genome can also be incorporated into the genome of the host cell. The viral genome will "remain silent" and be replicated at each cell replication, infecting thousands of cells. Then eventually, at chemical radiation or other provocating factors the viral part of the genome will be separated of the res of the genome and be released from the host cell, now killing thousands of cells. This corresponds to the lysogenic cycle.
+But after having entered the host cell, the viral genome can also be incorporated into the genome of the host cell. The viral genome will "remain silent" and be replicated at each cell replication, infecting thousands of cells. Then eventually, at chemical radiation or other provocating factors the viral part of the genome will be separated of the res of the genome and be released from the host cell, now killing thousands of cells. This corresponds to the lysogenic cycle<ref name="life cycle"></ref>.
 == Virus classification ==

Elisaari: /* Sources */

2009-04-12T14:21:15Z

Sources

← Eldre sideversjon		Sideversjonen fra 12. apr. 2009 kl. 14:21
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	== Sources ==		== Sources ==
	~~<references/>~~		1.Wikipedia

	~~Wikipedia~~		2.Fundamentals of molecular virology, by Nicholas H. Acheson

	Introduction to modern Virology, by N.J.Dimmock, A.J.Easton, and K.N.Leppard		3.Introduction to modern Virology, by N.J.Dimmock, A.J.Easton, and K.N.Leppard

	~~Fundamentals of molecular virology~~, by ~~Nicholas H. Acheson~~		4.Biology, by Campbell and Reece

	~~Biology, by Campbell and Reece~~		<references/>

Elisaari: /* Sources */

2009-04-12T14:19:06Z

Sources

← Eldre sideversjon		Sideversjonen fra 12. apr. 2009 kl. 14:19
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	== Sources ==		== Sources ==
			<references/>

	Wikipedia		Wikipedia

	Introduction to modern Virology, by N.J.Dimmock, A.J.Easton, and K.N.Leppard		Introduction to modern Virology, by N.J.Dimmock, A.J.Easton, and K.N.Leppard

	Fundamentals of molecular virology, by Nicholas H. Acheson		Fundamentals of molecular virology, by Nicholas H. Acheson

	Biology, by Campbell and Reece		Biology, by Campbell and Reece

Elisaari: /* Shape */

2009-04-12T14:18:17Z

Shape

← Eldre sideversjon		Sideversjonen fra 12. apr. 2009 kl. 14:18
Linje 33:		Linje 33:

	Lowest possible energy makes the capsid the strongest possible.		Lowest possible energy makes the capsid the strongest possible.
	In 1957, Fraenkel-Conrat and Williams showed that when mixtures of purified Tobacco Mosaic Virus RNA and coat proteins were put together they folded into virus particles. The discovery that virus particles formed spontaneously from purified subunits showed that this arrangement put the subunits in their state with maximum free energy, or lowest possible energy state<ref name="~~chaudry~~">~~Chaudry, Scotter, Blackburn, Ross, Boxall, Castle, Aitken & Watkins, "Applications and implicatons of nanotechnologies for the food sector", Food Additives and Contaminants, March 2008~~</ref>.		In 1957, Fraenkel-Conrat and Williams showed that when mixtures of purified Tobacco Mosaic Virus RNA and coat proteins were put together they folded into virus particles. The discovery that virus particles formed spontaneously from purified subunits showed that this arrangement put the subunits in their state with maximum free energy, or lowest possible energy state<ref name="shape">http://www.microbiologybytes.com/introduction/structure.html</ref>.
	As the proteins of a capsid aren’t symmetric, the lowest possible energy arrangement for non-symmetric particles is symmetric. The capsids are helical, isocahedral or both.		As the proteins of a capsid aren’t symmetric, the lowest possible energy arrangement for non-symmetric particles is symmetric. The capsids are helical, isocahedral or both.

Elisaari: /* Shape */

2009-04-12T14:16:10Z

Shape

← Eldre sideversjon		Sideversjonen fra 12. apr. 2009 kl. 14:16
Linje 33:		Linje 33:

	Lowest possible energy makes the capsid the strongest possible.		Lowest possible energy makes the capsid the strongest possible.
	In 1957, Fraenkel-Conrat and Williams showed that when mixtures of purified Tobacco Mosaic Virus RNA and coat proteins were put together they folded into virus particles. The discovery that virus particles formed spontaneously from purified subunits showed that this arrangement put the subunits in their state with maximum free energy, or lowest possible energy state.		In 1957, Fraenkel-Conrat and Williams showed that when mixtures of purified Tobacco Mosaic Virus RNA and coat proteins were put together they folded into virus particles. The discovery that virus particles formed spontaneously from purified subunits showed that this arrangement put the subunits in their state with maximum free energy, or lowest possible energy state<ref name="chaudry">Chaudry, Scotter, Blackburn, Ross, Boxall, Castle, Aitken & Watkins, "Applications and implicatons of nanotechnologies for the food sector", Food Additives and Contaminants, March 2008</ref>.
	As the proteins of a capsid aren’t symmetric, the lowest possible energy arrangement for non-symmetric particles is symmetric. The capsids are helical, isocahedral or both.		As the proteins of a capsid aren’t symmetric, the lowest possible energy arrangement for non-symmetric particles is symmetric. The capsids are helical, isocahedral or both.

Elisaari på 12. apr. 2009 kl. 14:10

2009-04-12T14:10:31Z

← Eldre sideversjon		Sideversjonen fra 12. apr. 2009 kl. 14:10
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	But after having entered the host cell, the viral genome can also be incorporated into the genome of the host cell. The viral genome will "remain silent" and be replicated at each cell replication, infecting thousands of cells. Then eventually, at chemical radiation or other provocating factors the viral part of the genome will be separated of the res of the genome and be released from the host cell, now killing thousands of cells. This corresponds to the lysogenic cycle.		But after having entered the host cell, the viral genome can also be incorporated into the genome of the host cell. The viral genome will "remain silent" and be replicated at each cell replication, infecting thousands of cells. Then eventually, at chemical radiation or other provocating factors the viral part of the genome will be separated of the res of the genome and be released from the host cell, now killing thousands of cells. This corresponds to the lysogenic cycle.

Elisaari på 12. apr. 2009 kl. 14:09

2009-04-12T14:09:57Z

← Eldre sideversjon		Sideversjonen fra 12. apr. 2009 kl. 14:09
Linje 98:		Linje 98:

	But after having entered the host cell, the viral genome can also be incorporated into the genome of the host cell. The viral genome will "remain silent" and be replicated at each cell replication, infecting thousands of cells. Then eventually, at chemical radiation or other provocating factors the viral part of the genome will be separated of the res of the genome and be released from the host cell, now killing thousands of cells. This corresponds to the lysogenic cycle.		But after having entered the host cell, the viral genome can also be incorporated into the genome of the host cell. The viral genome will "remain silent" and be replicated at each cell replication, infecting thousands of cells. Then eventually, at chemical radiation or other provocating factors the viral part of the genome will be separated of the res of the genome and be released from the host cell, now killing thousands of cells. This corresponds to the lysogenic cycle.

















	== Virus classification ==		== Virus classification ==

Elisaari: /* Life cycle */

2009-04-12T14:08:38Z

Life cycle

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 ==== Replication for the different types of viruses ====
 DNA-viruses:
-The replication of the genome takes place in the host cell’s nucleus.
+The genetic information of DNA virus is encoded in DNA, and the replication process takes place in the host cell's nucleus, in the presence of DNA polymerase.
 RNA viruses:
-Their genome replication takes place in the cytoplasm.
+In these viruses the genetic information is encoded in RNA. The replication process takes place in the cytoplasm.
-Retroviruses:
+Reverse transcribing viruses:
-Retroviruses are RNA viruses that replicate by using a viral reverse transcriptase enzyme to transcribe its RNA into DNA in the host cell. The DNA is then incorporated into the host's genome by an integrase enzyme. The virus then replicates as part of the host cell's DNA.
+Reverse transcribing viruses replicate using a reverse transcription. Their genetic information is encoded in RNA or DNA, which during replication is transcribed to DNA or RNA by a reverse transcriptase enzyme.
 [[Bilde:Retrovirus-structure.jpg|350px]]
 [[Bilde:retrovirus-lifecycle.jpg|350px]]
 == Virus classification ==

Elisaari: /* Life cycle */

2009-04-12T13:30:48Z

Life cycle

← Eldre sideversjon		Sideversjonen fra 12. apr. 2009 kl. 13:30
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	*'''Self-Assembly''' of the proteins to capsids that enclose the viral genome.		*'''Self-Assembly''' of the proteins to capsids that enclose the viral genome.
	*'''Releasing''' from the host cell by lysis or budding, killing the host cell. Enveloped viruses are released by budding, as they also take portions of the envelope of the host cell, whereas non-enveloped viruses are released by lysis.		*'''Releasing''' from the host cell by lysis or budding, killing the host cell. Enveloped viruses are released by budding, as they also take portions of the envelope of the host cell, whereas non-enveloped viruses are released by lysis.


			==== Replication for the different types of viruses ====

Elisaari: /* Life cycle */

2009-04-10T14:02:41Z

Life cycle

← Eldre sideversjon		Sideversjonen fra 10. apr. 2009 kl. 14:02
Linje 84:		Linje 84:

	But after having entered the host cell, the viral genome can also be incorporated into the genome of the host cell. The viral genome will "remain silent" and be replicated at each cell replication, infecting thousands of cells. Then eventually, at chemical radiation or other provocating factors the viral part of the genome will be separated of the res of the genome and be released from the host cell, now killing thousands of cells. This corresponds to the lysogenic cycle.		But after having entered the host cell, the viral genome can also be incorporated into the genome of the host cell. The viral genome will "remain silent" and be replicated at each cell replication, infecting thousands of cells. Then eventually, at chemical radiation or other provocating factors the viral part of the genome will be separated of the res of the genome and be released from the host cell, now killing thousands of cells. This corresponds to the lysogenic cycle.