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Pyruvate decarboxylase

2010-11-12T19:29:28Z

090989720:

Pyruvate decarboxylase is an enzyme which removes a CO2 molecule from [[Pyruvate|pyruvate]] to give an [[Acetaldehyde|acetaldehyde]], and is notably the first enzyme in the [[Pyruvate Dehydrogenase Complex|pyruvate dehydrogenase complex]]. It is a heterotetramer consisting of 2 alpha and 2 beta subunit. The alpha subunits are encoded by [[PDHA1 gene|PDHA1 gene]] which is located on Xp22.2-p22.1, the beta subunits are encoded by the [[PDHB|PDHB gene]], which is located on chromosone 3p. Brown et al., (1994) discovered that the active site for the [[Enzyme|enzyme]] is contained on the alpha subunit.

Pyruvate decarboxylase

2010-11-12T19:25:52Z

090989720:

Pyruvate decarboxylase is an enzyme which removes a CO2 molecule from [[Pyruvate|pyruvate]] to give an [[Acetaldehyde|acetaldehyde]], and is notably the first enzyme in the [[Pyruvate Dehydrogenase Complex|pyruvate dehydrogenase complex]]. It is a heterotetramer consisting of 2 alpha and 2 beta subunit. The alpha subunits are encoded by [[PDHA1 gene|PDHA1 gene]] which is located on Xp22.2-p22.1, the beta subunits are encoded by the [[PDHB|PDHB gene]], which is located on chromosone 3p. The active site for the [[Enzyme|enzyme]] is contained on the alpha subunit.

Pyruvate decarboxylase

2010-11-12T19:20:39Z

090989720:

Pyruvate decarboxylase is an enzyme which removes a CO2 molecule from [[Pyruvate|pyruvate]] to give an [[Acetaldehyde|acetaldehyde]], and is notably the first enzyme in the [[Pyruvate Dehydrogenase Complex|pyruvate dehydrogenase complex]]. It is a heterotetramer consisting of 2 alpha and 2 beta subunits<references />[http://www.ncbi.nlm.nih.gov/omim/300502 http://www.ncbi.nlm.nih.gov/omim/300502]<references />. The alpha subunits are encoded by [[PDHA1 gene|PDHA1 gene]] which is located on Xp22.2-p22.1, the beta subunits are encoded by the [[PDHB|PDHB gene]], which is located on chromosone 3p. The active site for the [[Enzyme|enzyme]] is contained on the alpha subunit.

Pyruvate decarboxylase

2010-11-12T19:06:00Z

090989720: Created page with 'Pyruvate decarboxylase is an enzyme which removes a CO2 molecule from pyruvate to give an acetaldehyde, and is notably the&nbsp…'

Pyruvate decarboxylase is an enzyme which removes a CO2 molecule from [[pyruvate|pyruvate]] to give an [[acetaldehyde|acetaldehyde]], and is notably the first enzyme in the [[Pyruvate_Dehydrogenase_Complex|pyruvate dehydrogenase complex]]. It is a heterotetramer consisting of 2 alpha and 2 beta subunits. The alpha subunits are encoded by [[PDHA1 gene|PDHA1 gene]] which is located on Xp22.2-p22.1, the beta subunits are encoded by the [[PDHB|PDHB ]]gene, which is located on chromosone 3p. The active site for the [[Enzyme|enzyme]] is contained on the alpha subunit.

Pyruvate Dehydrogenase Complex

2010-11-12T18:36:08Z

090989720:

Pyruvate Dehydrogenase Complex is a multi [[Enzyme|enzyme]] complex which catalyzes the conversion of [[Pyruvate|pyruvate]] to [[Acetyl-CoA|acetyl-CoA]] and CO2. It is important in [[Metabolism|metabolism]] as it is the linking step between [[Glycolysis|glycolysis]] and the [[citric acid cycle|citric acid cycle]]. The complex consists of 3 enzymes;

*[[Lipoamide reductase-transacetylase|lipoamide reductase-transacetylase]]
*[[Dihydrolipoyl dehydrogenase|dihydrolipoyl dehydrogenase]]
*[[Pyruvate decarboxylase|pyruvate decarboxylase]]

The enzymes form a channel in the [[mitrochondrial matrix|mitrochondrial matrix]], passing the reaction intermediates directly from one [[Enzyme|enzyme]] to the next. This increases the efficiecy of the enzmes as the intermediate substances are unstable, therefore having the enzymes close together allows for maximum production of acetyl-CoA.

Cholera

2010-11-12T18:07:08Z

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Cholera is a water borne disease caused by [[Vibrio cholerae|Vibrio cholerae]]. The main symptom of Cholera is diarrhoea. This is caused by movement of electrolytes from the [[epithelial cells|epithelial cells]] into the lumen of the gut, subsequently follwed by water. The Cholera toxin increases the activity of [[Adenylyl_cyclase|adenylate cyclase]]. This results in greater production of [[cyclic AMP|cyclic AMP ]](cAMP) and cAMP activates [[Protein Kinase A|Protein Kinase A]] (PKA) in [[CFTR|CFTR]] cells. In the CFTR cell PKA leads to the opening of chloride channels and chloride ions move from the cell into the lumen. Chloride ions are negatively charged and create an electrochemical gradient. Positively charged sodium ions also move into the lumen in order to balance this electrochemical gradient. The movement of sodium increases the osmolarity in the lumen and water then moves from the intracellular fluid into the extracellular

Phospholipid

2010-11-12T18:02:15Z

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Phospholipids are lipid molecules which have a [[Phosphate|phosphate]] group attached. 

They are highly abundant in [[Cell membranes|cell membranes]], where they form a [[Lipid bi-layer|lipid bilayer]], due to the [[amphiphatic|amphiphatic]] nature of their [[Hydrophilic|hydrophilic]] heads and [[Hydrophobic|h]][[Hydrophobic|ydrophobic]] tails.

Phospholipid

2010-11-12T18:01:43Z

090989720:

Phospholipids are lipid molecules which have a [[Phosphate|phosphate]] group attached. 

They are highly abundant in [[Cell membranes|cell membranes]], where they form a [[Lipid bi-layer|lipid bilayer]], due to the amphiphatic nature of their [[Hydrophilic|hydrophilic]] heads and [[Hydrophobic|h]][[Hydrophobic|ydrophobic]] tails.

Erythrocyte

2010-11-12T17:57:55Z

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An erythrocyte (or red blood cell) is one of the many different cells contained in the blood along with [[Leukocytes|leukocytes]] and [[Platelets|platelets]]. Every second, 2-3 million red blood cells are created<ref name="Blood Groups and Red Cell Atigens">Blood Groups and Red Cell Antigens, Dean.L., -http://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi?book=rbcantigen</ref>. These are made from the [[Haemopoetic pluripotent stem cells|haemopoetic pluripotent stem cells]] in the [[Bone marrow|bone marrow]].

They are involved in the transport of [[Oxygen|oxygen]] around the body through [[Haemoglobin|haemoglobin]]. However, they also have a role in determining [[Blood types|blood types]].

There are four main blood groups: A, B, O and AB. 

These are caused by different [[Antigen|antigens]] attached to the erythrocyte. They also have different sugars.

A blood group contains [[N-acetyl-galactosamine|N-acetyl-galactosamine]] whilst B blood group contains just galactosamine.

=== '''References''' ===

 <references />

Diabetes

2010-11-12T17:55:41Z

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There are five types of diabetes; types 1-5:

'''Type 1 Diabetes <ref>Surg Annu. 1978;10:1-21. Replacement of pancreatic beta cells as treatment for diabetes mellitus: a review. Jonasson O, Hoversten GH.</ref> - '''is also known as insulin-dependent diabetes melitus and is caused due to the immune system destroying [[pancreatic beta cells|pancreatic beta cells]] and so preventing them producing [[Insulin|insulin]].

'''Type 2 Diabetes<ref>Acta Med Indones. 2010 Oct;42(4):204-8. Insulin resistance profile among siblings of type 2 diabetes mellitus (preliminary study). Purnamasari D, Soegondo S, Oemardi M, Gumiwang I. Department of Internal Medicine, Faculty of Medicine, University of Indonesia - dr. Cipto Mangunkusumo Hospital. Jl. Diponegoro no. 71, Jakarta Pusat 10430, Indonesia.</ref>''' - is also known as non-insulin dependent diabetes mellitus and is caused due to [[Insulin|insulin]] no longer triggering its signalling cascade. Increasing obestiy in the world is making this type of diabetes increasingly common. 

'''Type 3 Diabetes - '''other specific types of diabetes

'''Type 4 Diabetes''' <ref>Diabetes Care. 2010 Oct 26. [Epub ahead of print] Body and Liver Fat Mass Rather Than Muscle Mitochondrial Function Determines Glucose Metabolism in Women with a History of Gestational Diabetes. Prikoszovich T, Winzer C, Schmid AI, Szendroedi J, Chmelik M, Pacini G, Krssák M, Moser E, Funahashi T, Waldhäusl W, Kautzky-Willer A, Roden M. Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria.</ref>- gestational diabetes mellitus (GDM)

'''Type 5 Diabetes''' <ref>Clin Chem. 2010 Nov 9. [Epub ahead of print] Prediabetes as a Therapeutic Target. Pour OR, Dagogo-Jack S. Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Tennessee Health Science Center, Memphis, TN.</ref>- impaired glucose tolerance (IGT) and impaired fasting glucose (IFG)

 

Nephrogenic diabetes insipidus is caused by mutations in [[aquaporin 2|aquaporin 2]] . Usually AQP2 is trafficked to the [[cell membrane|cell membrane]] where it facilitates the reabsorption of water into the cell. In the diseased state the channels are retained inside the cell resulting in the inability to control the concentration of urine being produced. <ref>The Journal of Cell Biology. (2003). Reversed polarized delivery of an aquaporin-2 mutant causes dominant nephrogenic diabetes insipidus 163(5):1099-109</ref>

 

 

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Pyruvate Dehydrogenase Complex

2010-11-10T14:27:06Z

090989720:

Pyruvate Dehydrogenase Complex is a multi enzyme complex which converts pyruvate to acetyl-CoA and CO2. The complex consists of 3 enzymes;

*lipoamide reductase-transacetylase
*dihydrolipoyl dehydrogenase
*pyruvate decarboxylase

The enzymes form a channel passing the reaction intermediates directly from one enzyme to the next.