The School of Biomedical Sciences Wiki - User contributions [en]

Co-enzyme

2018-12-09T14:43:28Z

180401176: Added hyperlinks

A coenzyme is a [[Molecule|molecule]] which helps the functioning and activity of an [[Enzyme|enzyme]] by binding and therefore activating it to form the [[Holoenzyme|holoenzyme]]<ref>Medicine Net, Coenzymes, https://www.medicinenet.com/script/main/art.asp?articlekey=13153</ref>. [[Coenzyme|Coenzymes]] are nonpolypeptide small [[Molecules|molecules]] or ions that are bound in the [[Active site|active site]], and can be chemically modified during the reaction so need to be replaced or regenerated afterwards<ref>Lodish H, Kaiser CA, Bretcher A, Amon A, Berk A, Kneger M, Ploegh H, Scott MP. Molecular Cell Biology. 7th Ed, New York: W.H. Freeman and Company. 2013.</ref>. Examples include [[NAD+|NAD+]] (nicotinamide adenine dinucleotide), [[FAD|FAD]] (flavin adenine dinucleotide) and [[Haem group|haem groups]] that bind [[Oxygen|oxygen]] in [[Haemoglobin|haemoglobin]]<ref>Lodish H, Kaiser CA, Bretcher A, Amon A, Berk A, Kneger M, Ploegh H, Scott MP. Molecular Cell Biology. 7th Ed, New York: W.H. Freeman and Company. 2013.</ref>.

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Hyperthyroidism

2018-12-09T14:42:20Z

180401176: Added hyperlinks

Hyperthyroidism is the condition that occurs from an overactive [[Thyroid|thyroid]]. Primary hyperthyroidism occurs because of a problem within the thyroid gland itself and secondary hyperthyroidism is a result of stimulation of the [[Thyroid gland|thyroid gland]] from excess [[Thyroid stimulating hormone|TSH (thyroid stimulating hormone]]) in circulation<ref>http://patient.info/doctor/hyperthyroidism</ref>.

Hyperthyroidism can be caused due to the [[Autoimmune disease|autoimmune disease]] Grave's disease, a condition caused by the immune system attacking the thyroid organ, causing over-production of thyroid hormone<ref>https://www.niddk.nih.gov/health-information/endocrine-diseases/hyperthyroidism</ref><ref>https://www.niddk.nih.gov/health-information/endocrine-diseases/graves-disease</ref>.

When stimulated by TSH the [[Thyroid_gland|thyroid]] gland produces [[Thyroxine|Thyroxine]] and Triiodothyronine, T4 and T3 respectively. T4 is produced in larger amounts but is inactive and must be converted to active T3. The release of T4 and T3 stimulates the negative feedback loop of the release of TSH from the anterior pituitary gland. Levels of TSH will be reduced and T4 will be increased in people with hyperthyroidism in comparison to the reference ranges which may change between laboratories<ref>http://www.pathology.leedsth.nhs.uk/pathology/ClinicalInfo/CommonTestsInvestigations/ThyroidFunctionTests/tabid/113/Default.aspx</ref>.

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Trisomy 21

2018-12-09T14:39:58Z

180401176: Corrected grammar and added a hyperlinks

Trisomy 21 is the name given to the [[Non disjunction|non-disjunction]] of [[Homologous chromosomes|homologous pairs of chromosomes]] 21 which leads to [[Down's syndrome|Down syndrome]]. "[[Trisomy|Trisomy]]" because, due to a nondisjunction event (failed separation of the [[Chromosome|chromosome]] pairs to separate during stage 1 or 2 of [[Meiosis|meiosis]]), there is an extra copy of [[Chromosome 21|chromosome 21]] in one of the gametes. At [[Fertilisation|fertilisation]], this [[Gamete|gamete]] will cause the [[Zygote|zygote]] to contain 3 copies of the chromosome 21.

Globular protein

2018-12-09T14:37:06Z

180401176: Added hyperlinks

Globular proteins are one of two types of proteins, the other being [[Fibrous protein|Fibrous proteins]]. Globular proteins have a compact and relatively spherical structure. Globular proteins are soluble in water and tend to be involved in metabolic functions, as opposed to fibrous proteins which tend to have a structural role. The [[Polypeptide|polypeptide]] chain of a globular protein can be folded into regions of α-helical or β-sheet structures forming the secondary structure of the protein. The secondary structure can be majoritively α-helical, majoritively β-sheet or a combination of both the structures. These [[Secondary structure|sec]][[Secondary structure|ondary structures]] are then folded on one another to form the globular [[Tertiary structure|tertiary structure]] of the protein. The [[Alpha-helix|α-helix]] and [[Beta-sheet|β-sheet ]]regions contain random coils forming irregular structured regions which allow for the [[Polypeptide|polypeptide]] chain to fold in a unique way. This means that every globular protein has a unique tertiary structure which is specific to the function of that protein.

Common globular proteins include [[Haemoglobin|haemoglobin]], [[Myoglobin|myoglobin]], [[Immunoglobulin|immunoglobin]] and [[Insulin|insulin]]<ref>Hardin, J, Bertoni, G and Kleinsmith, LJ 2012, Becker's World of the Cell, 8th edn, Pearson Bejamin Cummings. p.51</ref>.

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Endocrine

2018-12-01T22:19:51Z

180401176: Added a hyperlink to endicrinology

The Endocrine System is a complex signalling system involving the release of chemical signals known as, [[Hormones|hormones]] from endocrine organs into the [[Blood|bloodstream]] in response to a wide variety of stimuli.

[[Hormone|Hormones]] originate from endocrine [[Organ|organs]] located all around the body and include the [[Kidney|kidney]], [[Liver|liver]], [[Hypothalamus|hypothalamus]] and [[Pituitary gland|pituitary gland]]. The endocrine system also controls long-term changes in the body such as growth, sexual development and pregnancy. This system works with the neuronal system to control hormone secretion<ref>Sanders F. Crash Course: Endocrine and Reproductive Systems. 3rd Edition, Elsevie, 2007</ref>.

[[Endocrinology|Endocrinology ]]is the medicinal study of the endocrine system and the effects of changes to the system by genetic and microbial disease.

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Synaptic plasticity

2018-12-01T22:16:32Z

180401176: Corrected grammar and added a hyperlink to neurotransmitter

In neuroscience, synaptic plasticity is the ability of a [[Synapse|synapse]] to strengthen or weaken in response to a change in its activity<ref>Hughes, John R. (1958). "Post-tetanic Potentiation". Physiological Reviews 38 (1): 91–113. PMID 13505117</ref>. This can last a few seconds or a life time. Additionally, changes in plasticity of the synapse also results from variations in the number of [[Neurotransmitter|neurotransmitter]] recptors located on the synapse.<ref>Gerrow, Kimberly; Antoine (2010). "Synaptic stability and plasticity in a floating world". Current Opinion in Neurobiology 20 (5): 631–639. doi:10.1016/j.conb.2010.06.010</ref> There are several fundamental mechanisms that unite to achieve synaptic plasticity, these are, changes in the amount of neurotransmitters released into synapse and alterations in how effectively cells respond to these neurotransmitters.<ref>Gaiarsa, J.L.; Caillard O., and Ben-Ari Y. (2002). "Long-term plasticity at GABAergic and glycinergic synapses: mechanisms and functional significance". Trends in Neurosciences 25 (11): 564–570.</ref> Synaptic plasticity in excitatory as well as inhibitory synapses has been discovered to be dependent upon upon postsynaptic calcium release.<ref>Gerrow, Kimberly; Antoine (2010). "Synaptic stability and plasticity in a floating world". Current Opinion in Neurobiology 20 (5): 631–639.</ref> Since memories are hypothesized to be represented by immensely interconnected networks of synapses in the brain, it is therefore thought that synaptic plasticity is associated with learning and memory. 

In 1973, Terje Lømo and Tim Bliss described long-term potentation (otherwise known as LTP) in a publication in the ''Journal of Physiology.'' Long-term potentiation alters a synapses quality and quantity of transmission and is therefore a type of synpatic plasticity<ref>Silverthorn, Dee Unglaub., Johnson, Bruce R., Ober, William C., Garrison, Claire W., Silverthorn, Andrew C.(2009)Human Physiology: An integrated approach, 5th edition, New York: Pearson International. p286</ref>. 

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Non-polar solvent

2018-12-01T22:14:43Z

180401176: Grammar mistake

Solvents are used to dissolve a solute, forming a solution. Generally the are in a liquid form.

If the solvent is non-polar then the [[Electrons|electrons]] are shared evenly between the bonded [[Atoms|atoms]], so there are no significant charges on the atoms. Alternatively, polar bonds can cancel out the effects of one another giving a non-polar solvent.

Chemoheterotroph

2018-12-01T22:13:53Z

180401176: New page

 Chemoheterotophs obtain their energy from organic compounds by consuming other organisms.

Stereoisomerism

2018-12-01T22:04:22Z

180401176: Added a hyperlink to double bond and enantiomer

Stereoisomerism is defined as two [[Molecules|molecules]] which have the same molecular formula but the [[Atoms|atoms]] are arranged differently in space. This is due to the restricted rotation of the [[Carbon|carbon]] carbon [[Double_bond|double bond]]. There are two main types of stereoisomerism- Cis and Trans. Cis (or Z) isomers (Z standing for Zusammen, the German word for together) occurs when the same group or groups of a high priority are both found on the same side of the restricted [[Double bond|double bond]]. Trans (or E) isomers (E standing for Entgegen, the German word for opposite) occurs when the same groups or groups of a high priority are across the double bond and are so found on opposite sides.

The other major form of stereoisomerism is [[Optical isomerism|optical isomerism]]. [[Optical isomers|Optical isomers]] arise when a [[Chiral carbon|chiral carbon]] is present, this is a [[Carbon|carbon]] [[Atoms|atom]] attached to four different groups. Optical isomers are non-superimposable mirror images of each other and are called [[Enantiomer|enantiomers]]<ref name="null">Mathews CK, Van Holde KE, Ahern KG. Biochemistry, 3rd Ed, San Francisco: Benjamin Cummings. 2000 (9, 280)</ref>. One enantiomer is in a [[D-form|D-form]] and will rotate plane polarized light in a clockwise direction, to the right (dextro) while the [[L-form|L-form]] will rotate plane polarized light in an anticlockwise direction, to the left (laevo)<ref>Mathews CK, Van Holde KE, Ahern KG. Biochemistry, 3rd Ed, San Francisco: Benjamin Cummings. 2000 (9, 281)</ref>.

Ensuring the correct [[Enantiomer|enantiomer]] is present is critical in pharmaceuticals, as different isomers can have very different effects. It was the presence of the incorrect [[Enantiomer|enantiomer]] in [[Thalidomide|Thalidomide]] that caused deformities in the foetus to develop when it was given to pregnant women for morning sickness.

There are a number of different methods used to separate [[Enantiomers|enantiomers]]. For instance, the alteration of enantiomers into diastereomers by salt formation or covalent derivatisation allows separation due to variation in the physical and chemical properties that diastereomers possess. Secondly, enantiomers can also be separated by gas chromatography, high-pressure liquid chromatography and thin-layer chromatography. In addition [[Microorganisms|microorganisms]] can be used to separate enantiomers by enzyme action<ref>Dr Uwe Hofker, Prof. Dr. Gregor Fels, Separation of Enantiomers (Resolution of Racemates), http://www.chemgapedia.de/vsengine/vlu/vsc/en/ch/12/oc/vlu_organik/stereochemie/trennung_enantiomere.vlu.html, [Date accessed: 04/12/16]</ref>.

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Bronchi

2018-12-01T22:00:01Z

180401176: Added information about alveoli

The bronchi tree is a constituent of the [[Trachea|trachea]]. The trachea divides into two main bronchi: one for the left [[Lung|lung]] and the other for the right lung. The right bronchus is larger than the left bronchus. The bronchi tree forms a more branched tracheobronchial tree.

The primary bronchus then divides into a secondary lobar bronchi. This has three branches on the right and two branches on left. The secondary bronchi then further divide into tertiary bronchi that "supply the bronchopulmonary segments". After the tertiary bronchi, there is a conducting bronchiole and then terminal bronchioles<ref>Keith L. Moore, Arthur F. Dalley, Anne M. R. Agur, (2010), Clinically Oriented Anatomy, 6th Edition: Page 112-115, Philadelphia, Lippincott Williams &amp;amp;amp;amp; Wilkins, a Wolters Kluwer business.</ref>. Bronchiole passageways then evolve into alveoli, which is the site of oxygen and carbon dioxide exchange in the respiratory system.

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Dermis

2018-12-01T21:55:05Z

180401176: Corrected grammar mistakes

The dermis is the innermost layer of the [[Skin|skin]], found below the [[Epidermis|epidermis]] and above the subcutaneous tissue. It consists of  2 main layers: a thinner region called the papillay dermis and a thicker region called the reticular dermis.