TFY4260 - Cellebiologi og cellulær biofysikk - Sideversjonshistorikk

Yasharh på 19. apr. 2016 kl. 10:39

2016-04-19T10:39:22Z

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	[[Kategori: Fag]]		[[Kategori: Fag]]
	[[Kategori: ~~Valgbare~~ emner]]		[[Kategori: Obligatoriske emner]]
	[[Kategori: Fag 6. semester]]		[[Kategori: Fag 6. semester]]

Krandr på 4. mai 2015 kl. 17:57

2015-05-04T17:57:22Z

← Eldre sideversjon		Sideversjonen fra 4. mai 2015 kl. 17:57
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	== Om emnet ==		== Om emnet ==
	Emnet er obligatorisk for retning bionano.		Emnet er obligatorisk for retning bionano og tas i 6. semester.
	=== Faglig innhold ===		=== Faglig innhold ===

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	[[Kategori: Fag]]		[[Kategori: Fag]]
	[[Kategori: Valgbare emner]]		[[Kategori: Valgbare emner]]
			[[Kategori: Fag 6. semester]]

Krandr på 4. mai 2015 kl. 17:55

2015-05-04T17:55:04Z

← Eldre sideversjon		Sideversjonen fra 4. mai 2015 kl. 17:55
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	== Om emnet ==		== Om emnet ==
			Emnet er obligatorisk for retning bionano.
	=== Faglig innhold ===		=== Faglig innhold ===

Rssaetra på 4. mai 2015 kl. 17:54

2015-05-04T17:54:06Z

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	\|		\|
	\|*'''Institutt''': Institutt for fysikk		\|*'''Institutt''': Institutt for fysikk
	*'''Vurderingsform:''': Skriftlig eksamen.		*'''Vurderingsform:''': Skriftlig eksamen (100 %)
	*'''Hjelpemiddelkode'''~~: D:~~ ''Ingen trykte eller håndskrevne hjelpemidler tillatt. Bestemt, enkel kalkulator tillatt.''		*'''Hjelpemiddelkode D:''' ''Ingen trykte eller håndskrevne hjelpemidler tillatt. Bestemt, enkel kalkulator tillatt.''
	*'''Øvingsopplegg''': Laboratorieøvinger		*'''Øvingsopplegg''': Laboratorieøvinger
	}}		}}

Andestro på 4. mai 2015 kl. 17:27

2015-05-04T17:27:06Z

← Eldre sideversjon		Sideversjonen fra 4. mai 2015 kl. 17:27
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	=== Læringsressurser ===		=== Læringsressurser ===
			*[[Faglige notater: TFY4260]]

	=== Emnerapporter og referansegrupperrapporter ===		=== Emnerapporter og referansegrupperrapporter ===

Andestro på 4. mai 2015 kl. 17:25

2015-05-04T17:25:36Z

Vis endringer

Beckwith: /* Eksterne linker */

2009-03-26T13:01:29Z

Eksterne linker

← Eldre sideversjon		Sideversjonen fra 26. mar. 2009 kl. 13:01
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	High-mobility group proteins (HMG) are non-histone proteins associated with DNA. If these are removed from DNA active genes lose their affinity to DNase, which inhibits transcription. The nuclear matrix has also been shown to be closely related to DNA transcr		High-mobility group proteins (HMG) are non-histone proteins associated with DNA. If these are removed from DNA active genes lose their affinity to DNase, which inhibits transcription. The nuclear matrix has also been shown to be closely related to DNA transcr



			==Immunologi==
			===General===
			Fremmed stoff: Patogener
			*Bakterier, virus, sopp, toxiner, kreftceller
			Disse er antigener (antibody generator)

			From stem cells in the bone marrow a pluripotent haemopoietic cell is generated. This can evolve to lymphoid progenitor cells (the lymphocyte branch), which again can differentiate to T-cells, B-cells or NK cells. The hematopoietic cell can also become myeloid progenitor cells, which differentiates to platelets, erythrocytes, eosinophils, neutrophilcs, basophils and mast cells, as well as dendritic cells and macrophages (via monocytes).

			There are two main divisions of the immune system.

			=== Innate (nonspecific) immunity ===
			This is the bodies first defence against pathogens.
			Consists of:
			*Phagocytosis
			*Complements; proteins bind to bacteria, which generates a pore which causes desctruction of the bacteria.
			*Natural killer cells kill virusinfected cells by apoptosis
			*Secretion of interferon-<math>\alpha</math>

			===Acquired (specific) immunity===
			'''Examples:''' The covarage of a bacteria with antibodies, which can lead to phagocytosis or complements. Another example is cytotoxic (killer) T-cell which recognizes infected cell and causes apoptosis.

			There are two divisions of the acquired immune system: One is the antibpody responce. Antibodies are generated by B-lymphocytes and bind to antigens produced by the pathogen. The other is the cell-mediated response, which involves killer T-cells.

			==== Antibody production ====
			Specific antibodies are produced via the clonal selection of B-lymphocytes. From a precursor (lymphoid progenetor) cell millions of different varieties of B-lymphocytes are produced, each presenting a slightly different antibody. This happens via DNA reorganizing, especially in the hyper-variable segment of the antibody. When these cells are exposed to a matching antigen this binds to the antibody. This causes cloning of these B-lymphocytes, which then produce large amounts of the antibody against the detected antigen.
			The activated B-lymphocytes are called plasma cells. These are characterized by large amounts of endoplasmic reticulum to produce all the antibodies.

			The first time the cells are exposed to the antigens it can take some time (days to weeks) until the antibody level reaches its maximum. First the IgM level reaches it top, and a little later the IgG antibody reaches its maximum. The second time the body is exposed to this antigen there is a rapid, secondary response, where antibody levels, especially of IgG, reaches high levels quickly.

			The secondary response is due to immunologic memory, mediated via memory cells. In addition to the antibody producing B-lymphocytes that are produced in response to a first exposure of an antigen, the naïve (progenitor) cell also produces some memory cells.

			==== Lymphoid tissue ====
			Primary lymphoid tissue is the thymus and bone marrow, here lymphocytes develope. In the secondary lymphoid tissue (lymph nodes, spleen and Peyer's patches in intestine) the lymphocytes are exposed to antigens.

Beckwith: /* Eksterne linker */

2009-03-25T13:03:11Z

Eksterne linker

← Eldre sideversjon		Sideversjonen fra 25. mar. 2009 kl. 13:03
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	Stress vs strain curves show that it is the intermediate filaments that contribute the most to cellular strength, microfilaments and microtubules have more specialized tasks. The intermediate filaments are bound to the other elements of the cytoskeleton by plectin.		Stress vs strain curves show that it is the intermediate filaments that contribute the most to cellular strength, microfilaments and microtubules have more specialized tasks. The intermediate filaments are bound to the other elements of the cytoskeleton by plectin.

			== Regulation of gene expression ==

			=== Chemical modification ===
			DNA can be chemically modified by several side-groups. One example is the methylation of the cytosine bases of DNA. This causes the DNA to condence or pack more tightly. This modification happens on both chains and also gets copied when DNA is copied. This is a so-called epigenetic change.

			Histone can also be modified. Acetylation causes the electrostatic bonds between histone and DNA to weaken due to the histone losing some of its positive carge. This causes transcription of DNA to increase due to it being more available. Phosphorylation and metylation on the other hand cause the histone to pack tighter, which inhibits transcription of DNA.

			In DNA that is transcribed the histone H1 is missing (?).

			High-mobility group proteins (HMG) are non-histone proteins associated with DNA. If these are removed from DNA active genes lose their affinity to DNase, which inhibits transcription. The nuclear matrix has also been shown to be closely related to DNA transcr



	= Eksterne linker =		= Eksterne linker =

Beckwith: /* Membrane lipids */

2009-03-04T09:41:58Z

Membrane lipids

← Eldre sideversjon		Sideversjonen fra 4. mar. 2009 kl. 09:41
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	=== Membrane lipids ===		=== Membrane lipids ===

	Phospholipids are lipids consisting of long-chain fatty acids, glycerol and ~~phosphate, and sometimes associated molecules (e.g. choline~~)~~, while sphingolipids consist of fatty acids, sphingosine~~ and phosphate~~, and sometimes associated molecules~~. Sterols (steroid alcohols) consist of three six-carbon rings and one five-carbon ring, all interconnected, with a hydroxyl group at carbon-3 on the A ring, and various side-chains.		Phospholipids are lipids consisting of long-chain fatty acids, a molecule (glycerol for ''phosphoglycerides'' and sphingosine for ''sphingolipids'') and phosphate. Sterols (steroid alcohols) consist of three six-carbon rings and one five-carbon ring, all interconnected, with a hydroxyl group at carbon-3 on the A ring, and various side-chains.

	Common ~~phospholipids~~ are ''phosphatidylcholine'', ''phosphatidylethanolamine'' and ''phosphatidylserine'', where the last part of the name signifies what group is bound to the phosphate group. ''Sphingomyelin'' is an important sphingolipid, where choline is the phosphate-bound group.		Common phosphoglycerides are ''phosphatidylcholine'', ''phosphatidylethanolamine'' and ''phosphatidylserine'', where the last part of the name signifies what group is bound to the phosphate group. ''Sphingomyelin'' is an important sphingolipid, where choline is the phosphate-bound group.

	The properties of the membrane is decided by many factors. The ratio between headgroup area and chain length and diameter decides what kind of shape the lipids will self-assemble to. Two fatty-acid chains of 12-20 carbon atoms (with 16 or 18 being most common) are by far the most common in cell membranes, as these form stable lipid bilayers. The bilayers will form closed surfaces to avoid contact between the hydrophobic fatty acids and water. Saturated lipids form stiffer membranes, while unsaturated lipids form more fluid membranes due to lower packing density.		The properties of the membrane is decided by many factors. The ratio between headgroup area and chain length and diameter decides what kind of shape the lipids will self-assemble to. Two fatty-acid chains of 12-20 carbon atoms (with 16 or 18 being most common) are by far the most common in cell membranes, as these form stable lipid bilayers. The bilayers will form closed surfaces to avoid contact between the hydrophobic fatty acids and water. Saturated lipids form stiffer membranes, while unsaturated lipids form more fluid membranes due to lower packing density.

Beckwith: /* Acquisition of cytosolic proteins */

2009-03-03T15:03:41Z

Acquisition of cytosolic proteins

← Eldre sideversjon		Sideversjonen fra 3. mar. 2009 kl. 15:03
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	=== Acquisition of cytosolic proteins ===		=== Acquisition of cytosolic proteins ===
	Many mitochondrial proteins are synthesized by the free ribosomes in the cytosol. Following a water-soluble protein: A protein of the heat shock protein family (HSP70) binds and stabilizes these proteins, which also have a specific sequence known as a ''transit sequence''. This transit sequence binds to a receptor known as the translocase of the outer mitochondrial membrane (TOM). As the polypeptide passes through the pores of TOM and TIM (transit protein of the inner mitochondrial membrane) in the membrane the HSP70 proteins dissociate (via ATP hydrolyzation). The transit sequence is cleaved off the polypeptide by a membrane bound protein called transit peptidase, while the rest of the polypeptide entering the matrix is bound and stabilized by HSP70 and folds by with the aid of HSP60.		Many mitochondrial proteins are synthesized by the free ribosomes in the cytosol. Following a water-soluble protein: A protein of the heat shock protein family (HSP70) binds and stabilizes these proteins, which also have a specific sequence known as a ''transit sequence''. This transit sequence binds to a receptor known as the translocase of the outer mitochondrial membrane (TOM). As the polypeptide passes through the pores of TOM and TIM (transit protein of the inner mitochondrial membrane) in the membrane the HSP70 proteins dissociate (via ATP hydrolyzation). The transit sequence is cleaved off the polypeptide by a membrane bound protein called transit peptidase, while the rest of the polypeptide entering the matrix is bound and stabilized by HSP70 and folds by with the aid of HSP60. Energy in the form of both ATP and an electrochemical gradient i required to move these proteins across the membrane, although experiments seem to indicate that the gradient is only needed for the binding and penetration of the transit sequence.

	Various signal sequences cause the proteins to be targeted to other compartments of the mitochondrion, similar to the start and stop transfer sequences (see below).		Various signal sequences cause the proteins to be targeted to other compartments of the mitochondrion, similar to the start and stop transfer sequences (see below).