"Much time is spent in Ch. 12 of the textbook on loss of cell cycle control, leading to a malignant cancerous state. Describe at least two ways that normal, healthy cells keep the cell cycle in check. There are multiple ways that this occurs, so there are a lot of possibilities for your answer here. Explain how your chosen mechanisms work to keep cells from multiplying out of control." what kind of mechanisms is he referring to? G1 and such or density-dependent inhibition?
A way normal cells keep themselves intact is anchorage dependence. In order to divide, the cells must be attached to a substratum, such as the inside of a culture flask or the extracellular matrix of a tissue. This is one of the main systems in place to prevent cells from going out of control.
Another measure to prevent the growth of cancerous cells would be density-dependent inhibition, a phenomenon in which crowded cells stop dividing. Cultured cells normal divide until they form a single layer of cells on the inner surface of the culture flask, at which point the cells stop dividing. IF some cells are removed, those bordering the opening will continue to divide until the space is filled.
(PS. please tell me if this answers the question, there are many more ways. If these are not satisfactory, I will be happy to add more, just contact me ASAP).
That is exactly what I wanted to know! Thank you so much for your help! I appreciate it!
Also, "In Ch. 11, I gave you the example of apoptosis as a
mechanism of signal transduction. Find an example of another signal
transduction pathway, and explain it to me (you can NOT choose any of the
additional specific examples characterized in your textbook, however). It could
be from a plant, an animal, even a bacterial cell. Remember to characterize it
in terms of the 3 main aspects: reception, transduction, and response."
So, what are some examples of a mechanism of single transduction?
um, would cyclin-dependent kinases count as a signal transduction, I don't know if it is in your book.
Mar 29th, 2015
Are you using `Campbell biology ? 10th edition
Mar 29th, 2015
Well, if you are chapter 12 has an example of a growth factor called platelet-derived growth factor.
Honestly, I don't know any examples that were used outside of the text.
The fibroblasts sustain the PDGF receptor on their plasma membrane. The binding of PDGF molecules to these receptors will trigger a signal transduction pathway that allows the cells to pass the G1 checkpoint and divide. PDGF stimulates fibroblast division not only in the artificial conditions of cell culture, but also in an animals body. For instance, when injury occurs, platelets release PDGF. The resulting proliferation of fibroblasts help heal the wound.