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

Diploid cell

2018-12-10T11:10:23Z

180212826: added reference

Diploid cells, or somatic cells, contain two complete copies of each [[Chromosome|chromosome]] within the cell [[Nucleus|nucleus]]. The two copies of one [[Chromosome|chromosome]] pair up and are called [[Homologous chromosomes|homologous chromosomes]]. Human diploid cells consist of 46 chromosomes which includes all cells, with the exception of [[Gametes|gamete cells]] containing half of the required genetic information and are referred to as [[Haploid]]. Any cell with homologous chromolous is said to be [[Diploid|diploid]]. The diploid number of a [[Cell proliferation|cell]] is commonly abbreviated to 2n, where n is the number of chromosomes. Diploid cells are produced by [[Mitosis|mitosis]] and the [[Daughter cells|daughter cells]] are exact replicas of the [[Parent cell|parent cell]]. Examples of diploid cells include skin cells and [[Muscle cell|muscle cells]].

Conformational change

2018-12-04T13:33:15Z

180212826:

Conformational change is an alteration to the shape of [[Macromolecules|macromolecule]] due to changes in external or environmental factors.

Macromolecules are flexible thus it can change its shape in response to different factors<ref>https://en.wikipedia.org/wiki/Conformational_change</ref>.

The most common example for conformational change would be with proteins and cell signalling. [[G-protein Coupled Receptor|G-protein coupled receptors]] and their associated G-proteins use conformational change to transduce extracellular signals, whilst enzymes use conformational change to catalyse many reactions. Conformational change is an essential part of protein function.<ref>https://www.ncbi.nlm.nih.gov/pubmed/12081470</ref>

=== Typical Factors that could induce conformational change:  ===

*Temperature
*pH value
*Presence of substrate/inhibitor/ligand (especially in enzyme)
*Mutation  

=== References ===

<references />

Conformational change

2018-12-04T13:32:44Z

180212826:

Conformational change is an alteration to the shape of [[Macromolecules|macromolecule]] due to changes in external or environmental factors.

Macromolecules are flexible thus it can change its shape in response to different factors<ref>https://en.wikipedia.org/wiki/Conformational_change</ref>.

The most common example for conformational change would be with proteins and cell signalling. [[G-protein_Coupled_Receptor|G-protein coupled receptors ]]and their associated G-proteins use conformational change to transduce extracellular signals, whilst enzymes use conformational change to catalyse many reactions. Conformational change is an essential part of protein function.<ref>https://www.ncbi.nlm.nih.gov/pubmed/12081470</ref>

=== Typical Factors that could induce conformational change:  ===

*Temperature
*pH value
*Presence of substrate/inhibitor/ligand (especially in enzyme)
*Mutation  

=== References ===

<references />

Centrosomes

2018-12-04T13:29:50Z

180212826:

Centrosomes are the major [[Microtubules|microtubule]] organising centre in animal cells (they are lacking in plant cells). The centrosome controls the number, location and orientation of microtubules in cells. In animal cells specifically, the centrosome organises an array of microtubules that spreads outwards through the [[Cytoplasm|cytoplasm]], forming part of the cell [[Cytoskeleton|cytoskeleton]].  

The centrosome consists of a pair of [[Centrioles|centrioles]], surrounded by a matrix of proteins. The matrix of the centrosome itself contains many ring shaped structures that are all formed by one type of [[Tubulin|tubulin]], y-tubulin. Each single y-tubulin ring complex serves as the starting point for the growth of one microtubule. 

Centrosomes also play a key role in cell division as they provide the microtubules that form the [[Mitotic spindle|mitotic spindle]] and allow cell division to take place<ref>Alberts,B., Bray,D., Hopkin K., Johnson,A., Lewis,J., Raff,M., Roberts,K., Walter, P (2014). Essential Cell Biology. 4th ed. United States of America: Garland Science. p571-573.</ref>.  

=== References ===

<references />

Centrosomes

2018-12-04T13:29:01Z

180212826: corrected some mistakes

Centrosomes are the major [[Microtubules|microtubule]] organising centre in animal cells (they are lacking in plant cells). The [[Centrosome|centrosome]] controls the number, location and orientation of microtubules in cells. In animal cells specifically, the centrosome organises an array of microtubules that spreads outwards through the [[Cytoplasm|cytoplasm]], forming part of the cell [[Cytoskeleton|cytoskeleton]].  

The centrosome consists of a pair of [[Centrioles|centrioles]], surrounded by a matrix of proteins. The matrix of the centrosome itself contains many ring shaped structures that are all formed by one type of [[Tubulin|tubulin]], y-tubulin. Each single y-tubulin ring complex serves as the starting point for the growth of one microtubule. 

Centrosomes also play a key role in cell division as they provide the microtubules that form the [[Mitotic spindle|mitotic spindle]] and allow cell division to take place<ref>Alberts,B., Bray,D., Hopkin K., Johnson,A., Lewis,J., Raff,M., Roberts,K., Walter, P (2014). Essential Cell Biology. 4th ed. United States of America: Garland Science. p571-573.</ref>.  

=== References ===

<references />

Centrosomes

2018-12-04T13:27:56Z

180212826: added a link

Centrosomes are the major [[Microtubules|microtubule]] organising centre in animal cells (they are lacking in plant cells). The [[Centrosome|centrosome ]]controls the number , location and orientation of microtubules in cells. In animal cells specifically, the centrosome organises an array of microtubules that spreads outwards through the [[Cytoplasm|cytoplasm]], forming part of the cell [[Cytoskeleton|cytoskeleton]].  

The centrosome consists of a pair of [[Centrioles|centrioles]], surrounded by a matrix of proteins. The matrix of the centrosome itself contains many ring shaped structures that are all formed by one type of [[Tubulin|tubulin]], y-tubulin. Each single y-tubulin ring complex serves as the starting point for the growth of one microtubule. 

Centrosomes also play a key role in cell division as they provide the microtubules that form the [[Mitotic spindle|mitotic spindle]] and allow cell division to take place<ref>Alberts,B., Bray,D., Hopkin K., Johnson,A., Lewis,J., Raff,M., Roberts,K., Walter, P (2014). Essential Cell Biology. 4th ed. United States of America: Garland Science. p571-573.</ref>.  

=== References ===

<references />

Phage

2018-12-04T13:18:15Z

180212826: added reference

A Phage or [[Bacteriophage|Bacteriophage]] (from the Greek word phagein meaning "to devour") is a class of [[Virus|virus]] that will infect bacterial hosts. They are also used as model organisms for the study of the molecular biology and replication of viruses. Bacteriophage structures vary but all are composed of proteins containing DNA/RNA genome which allows them to replicate in the bacterial host. At a first stage the phage injects its DNA into the host bacterial cell (donor) and phage enzymes degrate host DNA. Then the cell synthesizes new phages that incorporate phage DNA and by mistake some host DNA. Transducing phage injects donor DNA and as a result donor DNA is incorporated into the recipients chromosome by recombination<ref>https://www.nature.com/scitable/definition/bacteriophage-phage-293</ref>. A key example is the [[T4 phage|T4 phage]] that will infect an ''[[E. coli|E. coli]]'' host cell. T4 phages are made up of a protein head containing the genetic information of the virus, along with a tail and tail fibres that permit the injection of genetic material into the host cell, these structures are made of [[Protein|protein]]<ref name="Brock Biology of Microorganisms">Michael Madigan, John Martinko, David Stahl, David Clark. (2012) Brock Biology of Microorganisms, Thirteenth Edition, San Francisco: Pearson. 267-268</ref>. T4 can only undergo a lytic instead of a lysogenic life cycle. Bacteriophages are thought to be the most abundant organisms in the world with an estimated 1031 in existence. This is a greater number than all other organisms put together, including bacteria<ref name="test">http://outbreaknewstoday.com/bacteriophage-therapy-treats-patient-near-death-mdr-acinetobacter-baumannii-45488/</ref>.

=== References ===

<references />

Phage

2018-12-04T13:16:43Z

180212826: Added text

A Phage or [[Bacteriophage|Bacteriophage]] (from the Greek word phagein meaning "to devour") is a class of [[Virus|virus]] that will infect bacterial hosts. They are also used as model organisms for the study of the molecular biology and replication of viruses. Bacteriophage structures vary but all are composed of proteins containing DNA/RNA genome which allows them to replicate in the bacterial host. At a first stage the phage injects its DNA into the host bacterial cell (donor) and phage enzymes degrate host DNA. Then the cell synthesizes new phages that incorporate phage DNA and by mistake some host DNA. Transducing phage injects donor DNA and as a result donor DNA is incorporated into the recipients chromosome by recombination. A key example is the [[T4 phage|T4 phage]] that will infect an ''[[E. coli|E. coli]]'' host cell. T4 phages are made up of a protein head containing the genetic information of the virus, along with a tail and tail fibres that permit the injection of genetic material into the host cell, these structures are made of [[Protein|protein]]<ref name="Brock Biology of Microorganisms">Michael Madigan, John Martinko, David Stahl, David Clark. (2012) Brock Biology of Microorganisms, Thirteenth Edition, San Francisco: Pearson. 267-268</ref>. T4 can only undergo a lytic instead of a lysogenic life cycle. Bacteriophages are thought to be the most abundant organisms in the world with an estimated 1031 in existence. This is a greater number than all other organisms put together, including bacteria<ref name="test">http://outbreaknewstoday.com/bacteriophage-therapy-treats-patient-near-death-mdr-acinetobacter-baumannii-45488/</ref>.

=== References ===

<references />