Category Archives: 02 Cells
Resources for the Cells topic
It’s Movember! Grow a mo and raise awareness of cancer.
Serendipitously timed, Grade 11 are looking at cell division as some of the male teachers are growing their mo’s for Movember:
“Men sporting Movember moustaches, known as Mo Bros, become walking, talking billboards for the 30 days of November* and through their actions and words raise awareness by prompting private and public conversation around the often ignored issue of men’s health.”
From the MoVember website.
*Actually, we’re doing Nov 10th – Dec 10th, due to the holiday and being a bit slow on the uptake.
So what’s it got to do with Biology?
Well, tumours – such as prostate and testicular cancer in men; breast, uterine, cervical and ovarian cancer in women; and cancer of everything else in everyone else – are simply the result of uncontrolled cell division. Through apoptosis (programmed cell death) or damage (necrosis), cells are destroyed. These need to be replaced with other cells. As our cells are eukaryotic, they need to go through mitosis to ensure that complete copies of all the chromosomes make it into both daughter cells.
As with other cell processes, this is controlled by genes and, importantly, terminated when the cells have grown appropriately. If there is a mutation or problem with a tumour-suppressor gene, such as TP53, the process of cell division is not stopped and the cells grow out of control. This is a tumour. Alternatively, mutations can affect other genes (oncogenes), which encourage further growth.
Click here for a good 11-minute documentary on cancer development, from CancerQuest.
Tumours can start out benign – growths of cells that are not harmful. If these cells become malignant and invade other cells and damage tissues, this is known as cancer. Damage to other cells and tissues leads to illness and can be fatal if not treated early. As tumours grow, they can recruit blood vessels – called angiogenesis. Now you run the risk of metastasis – cells from the tumour breaking off, flowing through the blood and starting a new aggressive tumour in a different part of the body.
Environmental factors can encourage mutations in key cell-cycle-controlling genes. We all know, for example, that smoking can cause lung cancer, UV radiation can lead to skin cancer and the HPV virus can cause cervical cancer.
So why all the fuss about Movember?
Simply, men’s cancers receive less media attention and men tend to be less willing to talk openly about their health problems (unless, of course, they’re trying to get sympathy with a case of man-flu). As guys tend to put off going to the doctor and generally live a lifestyle that is higher-risk for cancer (high fat, high meat, alcohol, smoking, lack of exercise…), tumours can go unnoticed. Men are less likely to survive a cancer diagnosis than their more health-conscious lady friends.
Through cultivating the moustache, we can start conversations about these issues, raise money for education, prevention, research and treatment and promote anti-cancer behaviours:
- Healthy lifestyle choices and awareness of risk
- Self-checking and regular screening for at-risk groups
- Early diagnosis of and treatment for tumours, should they arise (animation)
So get mo-tivated and join the mo-alition of the willing. Take a mo-ment to think about cell division. And mo-an at the men in your life to make healthy choices. Ladies too can get involved – by becoming Mo-Sistas and also raising awareness. The BIS Team are called the BIS Upper Lips!
In the video above, he talks about how genome mapping can lead to giving an indicator of risk to men. Great technology, based on the Human Genome Project (link to 4.4 Genetic Engineering and Biotechnology).
For the class resources on 2.5 Cell Division, click here. Interestingly, and obviously, hair growth itself is a product of cell division. Something to think about as you grow the mo, yo.
Mesolens: see thousands of cells in detail at the same time
Living Water Flea, captured through the Mesolens, by Brad Amos at LMB
Currently on exhibition as part of the Royal Society’s 350th anniversary celebrations, the Mesolens is a giant microscope that can show large field-of-view images of living specimens in incredible detail – thousands of living cells in focus and in detail at the same time. Until now, scientists have had to rely on low-mag light microscopes to obeserve living specimens, or use sections of dead specimens on an electron microscope in order to get high-mag images.
Mesolens vs Hooke
Robert Hooke first drew a human flea in his 1665 book Micrographia. Along with van Leeuwenhoek, Hooke kick-started microbiology, and so it is a fitting tribute that some 345 years later, LMB give us their flea images. You can pan and zoom across a Mesolens image by clicking here
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Check out this short article from Wired.com explaining how the Mesolens works, and go to the Laboratory of Molecular Biology’s official site for the Mesolens. Can you distinguish between it and a normal light or electron microscope? What advantages will this give to researchers?
The Guardian has a gallery of images from Mesolens, and there is a short video showing image density from the LMB site, as well as a teachers guide to microscopy.
Hybrid Hearts: Stem Cell Transplants 2.0
“Can we use stem cells to make a new heart/eye/lung/liver etc?”
This is the predictable and perennial question that comes up from at least one student when we are looking at stem cells, genetic engineering, cell differentiation and transplanting. Until now, the answer has (perhaps in an oversimplified way) been ‘no’.
We can use stem cell transplants to treat lymphoma. Recently a young woman had a trachea transplant based on stem cell technology. Skin grafts from a patient’s own cultured cells are also possible, as are stem cell-based bladders. However, these are all rather simple technologies.
To treat lymphoma, bone marrow cells are replaced, and are all the same. The trachea transplant was a pre-existing trachea simply coated in the patient’s stem cells to prevent immune rejection. Skin transplants are basically sheets of epidermis that cover a wound, yet do not have the intricate functions of original skin: temperature regulation, secretion, senses. The bladder is a bag.
The challenge with using stem cells to transplant a more complex organ, such as a heart, is that it is not a simple sheet made of one type of cell. It is complex 3D structure, with a range of cells performing specific tasks within the organ. These cells have differentiated to perform their functions: cardiomyocytes (beating cells), vascular endothelial cells (smooth internal surfaces) and smooth muscle cells (blood vessel walls).
How can we get the stem cells to become the right type of cell, in the right position?
The answer to this question could be the key to opening up new doors in the search for viable transplantable organs in medicine, and bears much in common with the trachea case. It also marks a return to form for the NewScientist YouTube channel, who have this short clip of the new hearts in action:
A full article to accompany the footage is here.
In a nutshell:
Decellularised pig heart: the scaffold (NewScientist)
1. Find a suitable transplant organ, such as a pig’s heart.
2. Strip of all cells and DNA, using a detergent. Only the collagen ‘scaffold’ remains, as in the image of the decellularised heart to the right.
3. Coat the scaffold with the recipient’s stem cells.
4. Ensure that the blood supply is adequate and will provide the right signals for differentiation.
What is amazing in this case is how the cells ‘knew’ what specialised cells to become. The leader of the research group, Dr. Doris Taylor, puts it down to the mechanical stimulus of the pressure of the blood in the vessels and chambers and chemical signals from growth factors and peptides that remained on the stripped heart structure.
They even went as far as replacing a healthy rat’s heart with one of these new hybrid hearts. The rat survived for the trial, but she says they need to focus on producing more muscular hearts in order to ensure long-term survival of transplant recipients.
Food for thought:
Read the whole article and some of the links within it. Discuss these questions:
1. What are the potential uses for this kind of transplant technology?
2. What are the current limitations of this method and how might they be overcome?
3. What are the ethical issues related to using hybrid (pig-human) organs in medical transplants? How would you feel if you were the patient?
4. Who are the various stakeholders in this technology and what are their viewpoints?
Useful Sources:
Dr Doris Taylor’s research page from the University of Minnesota
NewScientist Article: Hybrid hearts could solve transplant problem
BioAlive stem cells links and resources
Can stem cells repair a damaged heart? from the NIH
Research reveals how stem cells build a heart, from Harvard news.
Protein Synthesis: Transcription and Translation (2009)
This is a re-post for the class of 2009 to revise and the 2010 group to catch on the first time… As always, click on the shadowed images for a link to an animation, or visit the links posted below.
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Core (for everyone):
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Additional Higher Level:
Click4Biology page: Transcription – Translation
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Further resources:
There are many decent Flash animations and the like on the internet, but the majority cannot be embedded. Below this YouTube video, there are some direct links to resources, some of which can be easily saved.
Learn.Genetics @ Utah
Transcribe and Translate (good, basic, interactive)
How do fireflies glow? (puts it in context)
University of Nebraska:
Protein Synthesis overview (Good enough for SL)
Transcription Details (fits DP Bio HL very well)
Translation Details (fits DP Bio HL very well)
John Kyrk: (visit the parent site at www.johnkyrk.com – excellent)
Transcription (fits DP Bio HL very well)
Translation (fits DP Bio HL very well)
St. Olaf College
Transcription (clear and simple)
Translation (clear and simple)
EDIT: Two more animations (from mrhardy’s wikispace, original source unknown)
WH Freeman
RNA Splicing tutorial (HL only)
Bio3400
Translation with a genetic code dictionary (shows position in the ribosome)
Some more in-depth animations (newly added):
Translation from Wiley Interscience
Translation from LSU Medschool
Translation from The Chinese University in Hong Kong
Protein targeting from Rockefeller University
Interactive Concepts in Biochemistry
Found this useful source on North Harris College’s linklist. 
Wiley.com have produced this online resource for Biochemistry and the Chemistry of Life, and it contains a whole load of interactives and animations.
It is an ideal resource for: photosynthesis, respiration, DNA replication, transcription, translation, cell structure, enzymes and protein synthesis.
Nikon Small World
OK, so no video, but WOW!
Have a look at some amazing images from the World Photomicrography Competition.
Children’s Hospital Boston – Great Flash apps for students
Thanks to Rod Murphy for this one.
eSchool News featured CHB’s site as site of the week and it’s well deserved. There are some great animations here, including a nice neurons and synapses animation, some stem cell resources, cancer information and a chance to have a go at
making an EM image.
Go have a look!
Imaging Technology Group’s Virtual Microscope – Amazing free software
This is an unbelievable free, open-source piece of software. It basically emulates a scanning electron microscope and allows you all kinds of fuctionality, including: wide range of magnifications of super-high quality images; mass spec analysis with false colouring of different elements present; control over colour, brightness and image position; a very nifty measurement/line tool that is just perfect for the the IB Cells statements on magnifications.
The download is 128MB for the package including three images ready to mount. When opened, you can download many more images (around 25-30MB each – huge and great quality).
It’s brilliant – stop reading this and go play with it.
Well, if you’re still reading…
Their excellent website also includes a series of animations on the basics of microscopy, videos on preparing mounts and even a section on careers in microscopy.
i-Biology 