The Scoop on Stem Cells

"Stem cells (center ones) can develop into any cell type. They are valuable as research tools and might, in the future, be used to treat a wide range of diseases. " (News Medical)

                                                         Credit: Judith Stoffer


Stem cells are "unspecialized" cells that have the potential and ability to become any cell in the body. A major characteristic of stem cells is their ability to multiply while maintaining the ability to become any cell in the body. However, the term stem cell is a generic term. There are many different type of stem cells: embryonic stem cells, adult stem cells, induced pluripotent cells (iPS), and pluripotent stem cells (PS). Some stem cells, such as those in bone marrow, can divide and replace worn out tissue. Embryonic stem cells can divide without differentiation for long periods of time, and are known to develop into cells and tissue of the three primary germ layers, the ectoderm, mesoderm, and endoderm.  Adult stem cells are found in organs and many tissues with a limited ability for self renewal and differentiation. They vary in their ability for differentiation, but they are usually limited to cell types of their cell of origin. This topic is still being investigated by scientists today. Induced pluripotent cells are adult cells that are reprogrammed to enter the embryonic cell stage. They do this by being forced to express factors that are important in maintain the cells. iPSC's were first found in 2006 inside of a mouse, by Takahashi and Yamanaka, and the first human ones were found the year after, by Takahashi and Yu. iPSC's have some characteristics of embryonic stem cells, and scientists are comparing the two to find important similarities and differences.

Stem cells are valuable resources and cells in our body that can be used to solve a variety of problems, and some scientists are looking towards stem cells as the answer to serious diseases such as cancer.

Sources:
Mandal, Ananya, Dr. "What Are Stem Cells?" News-Medical.net. News Medical, 10 Jan. 2010. Web. 31 Aug. 2015.

"Frequently Asked Questions." Stem Cell Basics: Introduction [Stem Cell Information]. National Institute of Health, Mar.-Apr. 2015. Web. 31 Aug. 2015.

Medical News Today. MediLexicon International, n.d. Web. 31 Aug. 2015.

A Pretty Sweet Lab!

Today, we tested the monomers of the macro-molecule carbohydrates . The monomers of carbs are sugars, or monosaccharides. We tested common sugars and measured their degrees of sweetness to see what the difference between each monomer was. The monomers we tested were : glucose, fructose, galactose,  lactose, maltose, sucrose, starch, and cellulose.  Glucose, fructose, and galactose are classified as monosaccharides, meaning that they only have one ring. Maltose, and lactose were disaccharides, meaning that they have two rings. Starch and cellulose are polysaccharides, so they were composed of many rings. We noticed an inverse relationship between the number of rings that each monomer had and the degree of sweetness that we measured. For example, we rated fructose as having a 100 degree of sweetness, while starch and cellulose each got a 0. So we concluded that as the number of rings went up, the degree of sweetness went down.
As the lab continued, we found it easy to relate these carbohydrates to foods that we had eaten before. Fructose tasted similar to honey, since it was really sweet. Cellulose, on the other hand, reminded us of paper, which made sense when we learned that cellulose is a main component of paper. Starch vaguely reminded us of vegetables, which also was a expected since starch is produced by many green plants.

After the lab, we decided to to an extension to see how humans tasted sweetness. According to NPR, the taste buds have about 50-100 taste cells on the outer tips of the bud, and a different percentage of buds taste sweetness, while other percentages taste salty, sour, bitter etc.. There are proteins on the tongue specifically for tasting sweetness, and a chemical reaction takes place when the sugar or sweetener encounters the protein. It sends a signal to the brain, and different parts of the central nervous system respond to the sweetness.


Source: "Getting a Sense of How We Taste Sweetness." NPR. NPR, 11 Mar. 2011. Web. 29 Aug. 2015.

Hana the Banana in her cabana in the savannah

Last week, we investigated the death of Hana the banana who was murdered in her banana in the savanna. After we marked all the external lacerations, we opened up Hana using a scalpel along the sagittiral plane. In the end, it was determined that Hana had died due to blunt force trauma to the posterior of the cranium.