Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
20 Cards in this Set
- Front
- Back
|
What is cell culture? |
technique used to grow cells or tissues outside the organism under strictly controlled conditions |
|
|
Describe how we would go about creating a cell culture |
1. Cells are removed from tissue using a) mechanical fragmentation b) trypsin (cuts sticky protein interaction between cells) c) EDTA (removes metal ions, which act as cofactors to proteins, making them sticky)
2. Dissasociated cells are then placed in a nutrient medium containing a)amino acids b) salts c) glucose d) serum (containing growth factors and insulin) This nutrient medium mimicks the conditions found in our body to promote cell growth
3. Cells in nutrient medium are incubated in a CO2 incubator at 37 degrees
|
|
|
Define primary cell culture |
Cells taken directly out of organisms |
|
|
Whats the maximum number of times a primary cell culture can be passaged |
50 times. This is the hayflick limit. |
|
|
When does contact inhibition occur |
Usually within a confluent monolayer of primary cell culture, where the cell density is too high for continued growth |
|
|
Define senescence |
When cells stop dividing as they have reached the hayflick limit |
|
|
Define cell line |
cells which are transformed and able to grow indefinitely
|
|
|
Name 4 differences between cell lines and primary cell cultures |
1. Cell lines do not undergo contact inhibition, so they grow on top of one another 2. Cell lines not undergo senescence and so they can be passaged past the hayflick limit 3. Primary cell cultures are elongated, cell lines are rounded.
|
|
|
What was the name of the first human cell line |
HeLa. Came from Henriatta Lacks. Had cervical cancer. Then some scientist took her tumour cells after she died. kicked her when she was down. win some/lose some. |
|
|
What are the two processes stem cells undergo in terms of division |
self-renewal (continuous self-division) and differentiation (asymmetric division could occur where one cell is a stem cell and the other is a differentiated cell that performs a certain function) |
|
|
Explain how we would form an embryonic stem cell line |
1. take the inner cell mass (containing high amounts of ES cells) from the embryonic blastocyst 2. Put the inner cell mass on a dish with a confluent monolayer of fibroblast feeder cells (cells that provide inner cell mass certain factors to stay alive) 3. Use trypsin to dissasociate a few of the stem cells from this growth 4. Take dissasociated cells and put them on a new confluent monolayer of fibroblast feeder cells 5. Repeat the process to establish a ES cell line |
|
|
What are embryoid bodies and what are the three types of differentiated cells they can grow into? |
Cells taken from an embryonic cell line, when put in a cell suspension, are called embryoid bodies. Embryoid bodies, when given certain growth factors, can be grown into differentiated cells that are of the a)endoderm b) mesoderm c)ectoderm germ layers. |
|
|
How many of these are true? Embryonic stem cells a) are pluripotent b) undergo senesence c) can be grown indefinitely in culture d) exhibit contact inihibition e) grow on top of one another |
3. a, c, e |
|
|
T/F most tissues contain adult stem cells |
True. |
|
|
What is the function of adult stem cells |
replenishing and repairing tissues |
|
|
Explain the specific location and function of intestinal adult stem cells, with specific regards to the stem cell niche |
Intestinal adult stem cells are located in the crypts of intestinal villi. They can either self renew (symmetrical division) or differentiate into functional epithelial cells. Epithelial cells are lost at the tips of the villi, so the intestinal stem cells are necessary to replenish these lost cells through asymmetrical division. The stem cells themselves are surrounded by other adjacent cells, wholly forming a stem cell niche, which provide signals to the stem cells to either self-renew or differentiate |
|
|
a) What are induced pluripotent stem cells?
b)How can we achieve these? |
a) Differentiated cells that have certain genes expressed within them to turn them into stem cells.
b) Stem cells have a characteristic of expressing certain genes. These genes code for transcription factors that activate genes required for self renewal, and repress genes that promote differentiation.
These genes are: Oct4, Sox2, Klf4 and a gene found in cancer cells, c-Myc
If we overexpress these genes in differentiated cells, they have the ability to revert back to stem cells, becoming Induced Pluripotent Stem cells. |
|
|
Which one of these genes would be most beneficial in transplant medicine?
a) p51 b) Sox2 c) Fuk-u 420 d) cdc13 |
b) Sox2 can be overexpressed in differentiated cells to turn them into induced pluripotent stem cells |
|
|
What happens to the cancer when cancerous stem cells differentiate into functional tissue cells? |
The cancer can be conferred to the differentiated cell. Very bad, as there is a wide variety of these differentiated cells, so it becomes significantly harder to treat. |
|
|
How many of these does cancer promote? a) apoptosis prevention b) polyubiquitination c) uncontrollable cell division |
2. A and C. Cancer prevents programmed cell death, and promotes uncontrollable cell division |
