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Glutamine

2018-10-23T23:36:30Z

170308904:

[[Image:Glutamine.png|right|Glutamine.png]]

Glutamine is one of the 20 naturally occuring [[Amino acids|amino acids]]. It can be abbreviated to three letters: 'Gln' or one letter: 'Q' and can be encoded for by 2 different [http://teaching.ncl.ac.uk/bms/wiki/index.php/Codon codons], CAA and CAG. Glutamine is a [[Polar|polar]] [[Molecule|molecule]] meaning that it has an [[Enzyme|enzymatic]] role and can bind [[Ligand|ligands]] and other [[DNA|DNA]]. [[Polar amino acids|Polar amino acids]] are found buried in a [[Protein|protein]] and can be [[Hydrogen bonds|hydrogen-bonded]] to other [[Polar amino acids|polar amino acids]] or to the [[Polypeptide|polypeptide]] backbone <ref>Molecular biology of the cell, Alberts, 5th edition, chapter 3, page 126-129.</ref><ref>Berg, J. M., Tymoczko, J. L., &amp;amp;amp;amp;amp;amp;amp; Stryer, L. (2002). Biochemistry (5th ed.). New York: W.H. Freeman.</ref>.

=== References ===

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Glutamine

2018-10-23T23:33:29Z

170308904:

[[Image:Glutamine.png|right|Glutamine.png]]

Glutamine is one of the 20 naturally occuring [[Amino acids|amino acids]]. It can be abbreviated to three letters: 'Gln' or one letter: 'Q' and can be encoded for by 2 different [[www.teaching.ncl.ac.uk/bms/wiki/index.php/Codon|codons]], CAA and CAG. Glutamine is a [[Polar|polar]] [[Molecule|molecule]] meaning that it has an [[Enzyme|enzymatic]] role and can bind [[Ligand|ligands]] and other [[DNA|DNA]]. [[Polar amino acids|Polar amino acids]] are found buried in a [[Protein|protein]] and can be [[Hydrogen bonds|hydrogen-bonded]] to other [[Polar amino acids|polar amino acids]] or to the [[Polypeptide|polypeptide]] backbone <ref>Molecular biology of the cell, Alberts, 5th edition, chapter 3, page 126-129.</ref><ref>Berg, J. M., Tymoczko, J. L., &amp;amp;amp;amp;amp;amp; Stryer, L. (2002). Biochemistry (5th ed.). New York: W.H. Freeman.</ref>.

=== References ===

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Glutamine

2018-10-23T23:32:40Z

170308904: added a link to the wiki page on codons

[[Image:Glutamine.png|right|Glutamine.png]]

Glutamine is one of the 20 naturally occuring [[Amino acids|amino acids]]. It can be abbreviated to three letters: 'Gln' or one letter: 'Q' and can be encoded for by 2 different [[www.teaching.ncl.ac.uk/bms/wiki/index.php/Codon|codons]], CAA and CAG. Glutamine is a [[Polar|polar]] [[Molecule|molecule]] meaning that it has an [[Enzyme|enzymatic]] role and can bind [[Ligand|ligands]] and other [[DNA|DNA]]. [[Polar amino acids|Polar amino acids]] are found buried in a [[Protein|protein]] and can be [[Hydrogen bonds|hydrogen-bonded]] to other [[Polar amino acids|polar amino acids]] or to the [[Polypeptide|polypeptide]] backbone <ref>Molecular biology of the cell, Alberts, 5th edition, chapter 3, page 126-129.</ref><ref>Berg, J. M., Tymoczko, J. L., &amp;amp;amp;amp;amp; Stryer, L. (2002). Biochemistry (5th ed.). New York: W.H. Freeman.</ref>.

=== References ===

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Proteoglycans

2018-10-23T17:59:44Z

170308904: added a link to the oligosaccharide page

Proteoglycans are large [[Protein|proteins]] with [[Transmembrane|transmembrane]], [[Intracellular domain|intra]]- and [[Extracellular domain|extracellular domains]] and [[Oligosaccharide|oligosaccharide]] chains attached to the extracellular domain. They are much larger than glycoproteins. The [https://teaching.ncl.ac.uk/bms/wiki/index.php/Oligosaccharide oligosaccharides] form part of the [[Glycocalyx|glycocalyx]] <ref>Alberts B., Johnson A., Lewis J., Raff M., Roberts K., Walter P. 2008. Molecular Biology of the Cell, 5th ed. New York, Garland Science.</ref>.

=== References ===

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Metal ion

2018-10-23T17:51:16Z

170308904: added hyperlink to the ions page

Metal [https://teaching.ncl.ac.uk/bms/wiki/index.php/Ion ions ]are paramount for metabolic processes in living [[Organisms|organisms]]. The nature of [[Metabolic processes|metabolic processes]] depend on the [[Proteins|proteins]] involved, that are formed from [[Amino acids|amino acids]]. [[Cysteine|Cysteine]] is special as it can form complexes with metal ions due to its [[Thiol group|thiol group]] at the end of the R chain<ref> A novel cysteine-rich sequence motif. Cell. 1991 Feb 8;64:483-4.</ref>. For example its ability to bind to [[Nickel|nickel ions]].

=== References ===

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G-proteins

2017-12-04T17:19:07Z

170308904: Added links to other pages

[[Guanine nucleotide|Guanine nucleotide]] binding [[Protein|protein]] binds [[GTP|GTP]] when activated, which it [https://teaching.ncl.ac.uk/bms/wiki/index.php/Hydrolysis hydrolyses ]to [[GDP|GDP]]. G-proteins are a form trimeric proteins, meaning they have 3 subunits, Alpha, Beta and Gamma. The trimeric protein is activated by the displacement of GDP with GTP through a conformation change in the receptor to which the G-protein is coupled, which in turn causes the release of the alpha subunit (Gsα). The active form of the [[Protein|protein]] can interact with a number of downstream effectors such as [[Adenylyl cyclase|adenylyl cyclase]] (producing [[CAMP|cAMP]] from [[ATP|ATP]]), and [[Phospholipase C|phospholipase C]] ([[PLC|PLC]]).

[[G-proteins|G-proteins]] can be divided into two families - the [[Heterotrimeric G-proteins|heterotrimeric G-proteins]] and the small or [[Mono-meric G-proteins|mono-meric G-proteins]], which are mainly involved with enzyme-linked receptors<ref>https://courses.washington.edu/conj/bess/gpcr/gpcr.htm</ref>.

G-protein coupled receptors ([[GPCR|GPCRs]]) upon binding of a [[Stimulus|stimulus]] (in the form of a signalling ligand molecule) activate their coupled G-protein.

The structure of a [[GPCR|GPCR]] is of a serpentine receptor, with 7 transmembrane spans, with 3 exoloops and 4 cytoloops. The [https://teaching.ncl.ac.uk/bms/wiki/index.php/N-terminal N-terminal] is found on the extracellular side of the membrane and the C-terminal found on the cytosolic side of the membrane.

=== G protein families ===

There are 4 major families of [[Heterotrimeric G-proteins|heterotrimeric G-protein]]. G-proteins are divided based on the homology of their alpha subunit. Each receptor only affects one type of G-protein<ref name="Alberts et al.,2008: 919">Bruce Alberts, Alexander Johnson, Julian Lewis, Martin Raff, Keith Robers and Peter Walter(2008) Molecular Biology of The Cell, 5th edition, USA: Garland Science. pg 919</ref>.

There are 20 alpha subunits, 6 beta subunits and 12 gamma subunits in human that make up the diversity of G-proteins.

Heterotrimeric G-proteins contain three subunits: [[Alpha|alpha]], [[Beta|beta]] and [[Gamma|gamma]]. In the inactive form, all three subunits are associated together and [[GDP|GDP]] binds to the alpha subunit and the alpha and gamma subunits are covalently bonded to lipid molecules in the membrane<ref>https://courses.washington.edu/conj/bess/gpcr/gpcr.htm</ref>. On activation, there is a conformational change in the alpha subunit, which now binds to [[GTP|GTP]] and dissociates from the [[Beta-gamma complex|beta-gamma complex]]. The alpha subunit and beta-gamma complex can now interact with different effectors to bring about a response. The [[GTPase|GTPase]] activity of the alpha subunit causes the loss of [[GTP|GTP]] from the binding site in the alpha subunit, and another [[GDP|GDP]] binds, resetting the system<ref>Alberts et al., Molecular Biology Of The Cell, Fifth Edition</ref>. G-proteins can be classified as either trimeric, which are seen bound to G protein-coupled receptors, or as monomeric, which lack the three different subunits that trimeric G-proteins have<ref>Alberts B, et al. Molecular biology of the cell, 6th ed. New York: Garland Science, Taylor and Francis Group; 2015.</ref>.

==== Family I ====

Consists of [[Gs|G]][[Gs|s]] and [[Golf|G]][[Golf|olf]]. The alpha subunit mediates the function in both G-proteins. Gs activates [[Adenylyl cyclase|adenylyl cyclase]] and [[Calcium ion channels|Calcium ion channels]] while Golf activates [[Adenylyl cyclase|adenylyl cyclase]] in olfactory sensory neurons.

==== Family II ====

Consists of [[Gi|G]][[Gi|i]], [[Go|G]][[Go|o]] and [[Gt|G]][[Gt|t]]. The alpha subunit of Gi inhibits [[Adenylyl cyclase|adenylyl cyclase]] while the beta-gamma complex of Gi activates potassium ion channels. For Go, the beta-gamma complex activates [[Potassium ion channels|Potassium ion channels]] and at the same time inactivates [[Calcium ion channel|Calcium ion channel]]. Both alpha subunit and beta-gamma complex of Go activate [[Phospholipase C|phospholipase C]]-beta. The alpha subunit of Gt activates [[Cyclic GMP|cyclic GMP]] [[Phosphodiesterase|phosphodiesterase]] in vertebrate [[Rod photoreceptors|rod photoreceptors]].

==== Family III ====

Consists of [[Gq|G]][[Gq|q]]. The alpha subunit of Gq functions to activate [[Phospholipase C|phospholipase C]]-beta.

==== Family IV ====

Consists of [[G12/13|G]][[G12/13|1]][[G12/13|2/13]]. The action of alpha subunit of G12/13 is to activate [[Rho|Rho]] family monomeric [[GTPase|GTPase]].

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Complete Dominance

2017-12-04T17:17:26Z

170308904: Added links to other pages

Complete dominance is where a [[Dominant allele|dominant allele]] completely masks the presence of the [[Recessive alleles|recessive allele]]. An example of this can be shown in the cross below: 

Azazel is a red skinned Homo-Superior [https://teaching.ncl.ac.uk/bms/wiki/index.php/Homozygous homozygous ]with the u gene coding for red skin.

Raven is a blue skinned Homo-Superior homozygous with the U gene coding for blue skin. 

{| width="200" border="1" cellpadding="1" cellspacing="1"
|-
|
| u
| u
|-
| U
| Uu
| Uu
|-
| U
| Uu
| Uu
|}

As shown by the cross, all the offspring should have a Uu [https://teaching.ncl.ac.uk/bms/wiki/index.php/Genotype genotype ]for skin color. However, as the U allele is completely dominant over the u allele, their child Kurt expresses a [https://teaching.ncl.ac.uk/bms/wiki/index.php/Phenotype phenotype ]with completely blue skin.

Allolactose

2017-12-04T17:15:14Z

170308904: Added links to other pages

Allolactose is a molecule made of galactose and glucose joined by alpha - 1,6 [https://teaching.ncl.ac.uk/bms/wiki/index.php/Glycosidic_bond glycosidic bond]. It is the side product of the conversion of lactose to galactose and glucose by beta- galactosidase. Allolactose is an inducer of [https://teaching.ncl.ac.uk/bms/wiki/index.php/Lac_operon lac operon] in prokaryotes. It binds to the lac repressor causing a comformational change which reduces the reprossor's affinity for the operator DNA. As results [https://teaching.ncl.ac.uk/bms/wiki/index.php/RNA_polymerase RNA polymerase] can initiate transcription of the lac genes.<ref>Berg JM, Tymoczko JL, Gatto GJ, Stryer L. Biochemistry. 8th ed. New York: W.H. Freeman &amp;amp; Commpany, a Macmillan Education Print. 2015</ref>

 

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Nerves

2017-12-04T17:11:15Z

170308904: Added a link to another page

Nerves are bundle of fibres in the body that transmits impulses in the [[Central nervous system|central nervous system]] via [[Neuron|neurons]] to initiate a response from a sense of an object either physically or mentally. [https://teaching.ncl.ac.uk/bms/wiki/index.php/Nerve_impulse Impulses ]from the central nervous system lead to the [[Peripheral Nervous System|peripheral nervous system]] where an impulse is transmitted to ensure a response.