From CellBiology

peer review

1. You seem to have done a lot of backgroud reading a large refence list. the layout is good and the picture help to depict some of the aspects covered. i would have liked to have read more regarding the abonormalies and diseases it relates to. maybe you should also think about putting in aome current research for this topic.(z3158969)

2. It is really good to have images for the structure part. Good use of heading and sub heading. The way of using dot point in the function/role part make me easier to understand. However, you can discuss more on the Abnormalities/Diseases part as well, it seems to be a bit rough.

3. you have put together a very well researched and well structures page. i only have a few things to add to what has already been said. maybe add in a glossary linking to some terminology used in the abnormalities section, some terms might not be understood very well unless you have a knowledge of path. also you could add a picture at the "structure of organelles" section to break the monotony of the text, just befor abnormalities. otherwise, content and layout is easy to follow and well researched. well done. (3191801)

4. Your page is very well written and the research was extensive. I liked the inclusion of images, it helped. Can't find any faults in it.

5. Love the layout of your page, the balance between text and figures is great. Also the flow of text in logical so well done!

Individual project notes

  • "In mammalian cells, MFN1 docks two juxtaposed mitochondria via its second coiled coil domain to promote fusion (53). The role of the two Mfns in fusion seems to be different. MFN1 has higher GTPase activity and induces fusion more efficiently than MFN2 (40). Furthermore, OPA1 requires MFN1 to mediate fusion, whereas MFN2 functions independent of OPA1 (18)." - Mitofusin 2: a mitochondria-shaping protein with signaling roles beyond fusion.[REVIEW] de Brito OM, Scorrano L. Antioxid Redox Signal. 2008 Mar;10(3):621-33. PMID: 18092941.
  • MFN2 is a pro-fusion protein
  • MFN2 genetic disease = Charcot Marie Tooth IIA (major phenotype: Loss of sensorimotor axons, Mitochondrial morphology: Probably fragmented, Involvement of organelles: endoplasmic reticulum and mitochondria.
  • "MFN2 may play a regulatory role in keeping the interaction between mitochondria and the organelle transport machinery. Given that most mutations cluster in the GTPase domain, the liaison should depend on the ability of MFN2 to hydrolyze GTP " - Mitofusin 2: a mitochondria-shaping protein with signaling roles beyond fusion.[REVIEW] de Brito OM, Scorrano L. Antioxid Redox Signal. 2008 Mar;10(3):621-33. PMID: 18092941.
  • The MFNs possess a GTPase and a coiled-coil domain located at the N-terminus of the proteins, exposed to the cytosol. Two TM regions form a U-shaped membrane anchor, ending in a cytosolic, C-terminal coiled-coil motif (53, 76). MFN1 on opposing mitochondrial membranes can bind in trans to bridge organelles, maintaining a distance of 95 Å between the two membranes (53). Whether this ability is shared by MFN2 is not yet clear. Conversely, MFN2 possesses an N-terminal RAS-binding domain that is not found in MFN1 (15), suggesting a role in other processes than membrane fusion.- Mitofusin 2: a mitochondria-shaping protein with signaling roles beyond fusion.[REVIEW] de Brito OM, Scorrano L. Antioxid Redox Signal. 2008 Mar;10(3):621-33. PMID: 18092941.
  • MFN1 mediates GTP-dependent teth- ering of mitochondria more efficiently than MFN2, and its GT- Pase activity is higher than that of MFN2, even if MFN2 has a greater affinity for GTP (40, 63). Finally, MFN1 but not MFN2 is essential for OPA1-mediated mitochondrial fusion. - Mitofusin 2: a mitochondria-shaping protein with signaling roles beyond fusion.[REVIEW] de Brito OM, Scorrano L. Antioxid Redox Signal. 2008 Mar;10(3):621-33. PMID: 18092941.

--Mark Hill 09:53, 20 April 2009 (EST) Lecture 8 homework?

--Mark Hill 18:32, 19 March 2009 (EST)You still need to provide feedback for Lecture 4 - Nucleus.

--Mark Hill 16:04, 30 March 2009 (EST) Thank you for your feedback. Yes the nuclear skeleton is quite unique in structure, we will discuss this again in the cytoskeleton lecture on intermediate filaments and in cell division.

--Mark Hill 10:36, 3 April 2009 (EST) You still need to answer the other homework questions. 2009_Student#Individual_Projects


  • Lecture 4 - Nucleus - What did you find interesting and did not know about the nucleus?
    • This lecture I learned about the inner section of the nuclear cytoskeleton, the nuclear lamina, which is comprised of a class of proteins called lamins. The outer lamina surface attaches to the inner nuclear membrane and the inner lamina surface is attached to the chromatin, anchoring each chromosome to its chromosomal territory within the nucleaus.
  • Lecture 5 - Exocytosis - What concept about exocytosis did you find difficult to understand?
    • The hardest concept this lecture for me was understanding the clear difference between RER and SER other than the fact that one has bound ribosomes. for example, if both are structurally the same what is the diference between them that makes lipids be digested in the SER and not the RER?
  • Lecture 7 - Mitochondria - What types of cellular processes require lots of energy from the mitochondria?
    • Some processes requiring lots of energy in a cell are cell division (e.g. chromosomal replication and division), mechanical movement (e.g. muscle contraction, movement of actin and myosin filaments, beating of flagella), cell growth (e.g. production of new protein) & maintainance of cell function (e.g. proton pump function for membrane potential).
  • Lecture 8 - Adhesion - What do the different "CAM" acronyms stand for?
    • The different CAMs are as follows: Ng-CAM=Neuronglia Cell Adhesion Molecule (found mostly on axons of neurons and on the apical surface of epithelial cells), L-CAM=Liver cell Adhesion Molecule (found in very early vertebrate embryos and on liver and other epithelial cells in adults), & I-CAM=Intercellular Cell Adhesion Molecule (found in low concentrations in the membranes of leukocytes and endothelial cells)
  • Lecture 10 - What is the name of the epidermal layer between the basal and granulosa layer and how does it relate to intermediate filaments?
    • Skin layers (deep to superficial): stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, stratum corneum.
    • The largest of the epidermal skin layers, the stratum spinosum consists of cuboidal epithelial cells connected to each other via desmosomes which help the skin resist damage from mechanical shearing and stress. The desmosomes are formed from the interaction of the cadherins attached to the dense plaque adjacent to the cell membrane at the site of the desmosome. The plaque is anchored in the cell membrane by intermediate filaments (Keratin) and the stratum spinosum is where the earliest stages of keratinization occur in the epidermis.

stratum spinosum wikidoc

  • Lab 6 - "If you've seen differences in the distribution of phenotypes in Tm4 over-expressing B35 cells versus control B35 cells, describe these differences. Formulate a hypothesis with regards to what changes on the molecular level may have occurred due to the over-expression of Tm4 that lead to morphological changes that you have observed"
    • Tm4 overexpressing cells displayed more pronged and stringed cells while the wildtype genotype has more broken fans and stumped cells. My hypothesis is that the Tm4 overexpression results in a reduced amount of polymerisation of the actin so smaller more slender processes were seen as opposed to the larger extensions seen in the wildtype cells.
  • Lecture 14 - Confocal Microscopy - What are the 2 main forms of generating confocal microscopy?
    • The two main types of confocal microscopes are: Confocal laser scanning microscopes & Spinning-disk (Nipkow disk) confocal microscopes.
  • Lecture 15 - Cell Cycle - What does "S" stand for in the S phase?
    • The S stands for synthesis as this is the stage where DNA is replicated.

Peer Assessment

I have peer assessed 3189168, 3193685, 3207164, 3187043, 3187644 & 3201482