AP Biology class blog for discussing current research in Biology

Author: ethansol

Do we never have to workoout again?

Could it really be possible to get all the benefits of a rigorous workout without moving a muscle?

Recent Biological findings show promise that protein supplements can cause similar effects as a full body workout. The protein is called Sestrin and as of now it has only showed compelling results in flies and mice. However this new drug could be the key to a more healthy population.


What evidence is there?

A Michigan University study set up an elaborate experiment involving flies climbing or flying up the inside of a test tube, only to be shaken back down to the bottom. This practice was repeated for hours on end to test the endurance of the flies. The researchers made use of multiple apparatus in order to effectively test multiple variables. One such variable was the amount of sestrin present in the flies muscles. This could be controlled through the genetic engineering of multiple generations of flies to select for certain traits like high or low amounts of sestrin. Through multiple lengthy trials it was determined that flies with higher amounts of sestrin showed better increases in endurance over time as well as perhaps the most important result, flies that were extremely abundant with sestrin were without exercise better suited to climb or fly for longer amounts of time than flies without it that had been training for longer. This result serves as a great case for why sestrin might be the super drug some speculate.

How does it work?

Sestrin, a part of a highly conserved family of proteins, is hypothesized to work by coordinating metabolic homeostasis by  selectively turning on and off different metabolic pathways as a means to imitate the effects of exercise.

What do you think?

Is sestrin truly the drug of the future? Personally I remain skeptical until  a multitude of studies come to similar conclusions. Are the days of gym memberships and unkept new years resolutions over? Leave a comment with your thoughts!

Should We Be Carbo-loading? The Effects of Resistant Starches on the Gut Microbiome.

What is Starch?

By definition starch is a polysaccharide composed of a chain of glucose molecules held together by glycosidic bonds. Starch is common in nearly all green plants and is used for short term energy storage.

Different Types of Starches

Starch can come in two distinct forms: amylopectin a compound with a complex system of branching glucoses, and amylose a simple straight chain of glucose molecules. Because of amylopectin’s larger and more complicated nature it has a much larger surface area than amylose making it significantly easier to digest. The amylose cannot effectively be broken down by the enzymes of the digestive system. Instead it is left to be dealt with by the human gut microbiome. For this reason it is commonly referred to as a resistant starch.

How are Resistant Starches Beneficial?

An international research article including authors from Harvard Medical School suggests that resistant starches have a myriad of benefits. Some resistant starches which thwart digestion in the stomach and small intestine, make their way all the way down to the large intestine where they are subject to fermentation by the microscopic bacteria of the human gut. The fermentation process can metabolize a multitude of different useful products. For example some significant and common place output of gut fermentation are simple fatty acids. One key short chain fatty acid created during this process is Butyrate, the preferred fuel oof the cells lining the colon. In addition to Butyrate there exist many other short chain fatty acids that help maintain and fuel the body. These fatty acids can be used for many different purposes, all beneficial to both the gut microbiome and the host. The benefits may range from weight loss to curbing the progression of chronic kidney disease.

In addition to their ability to be changed into more useful forms, resistant starches also serve to enhance the effectiveness of the gut microbiome. Constant ingestion of resistant starches can stimulate an increase in the size and health of gut microbiomes in addition to raising host metabolism.

Common Uses For Resistant Starches

Resistant starches are often used in weight reducing diets in order to encourage an increase in metabolic rates. Although results of these diets are often compelling, a diet must consist of all types of food groups and should contain a variety of vitamins and minerals. Eating only amylose and other resistant polysaccharides will not on its own help you achieve weight loss. It should be paired with exercise and an otherwise healthy diet.

Should resistant starches be used in dieting or do they promote malnutrition? There are many benefits to a diet high in resistant starches, including building up a healthy gut microbiome. However you cannot survive solely on carbohydrates. This is a complex question, and I would be interested in hearing your opinions in the comments.




3D Printing Organs, how long until this technology is ready?

An Organ Emergency

Since the late 1990s bioengineers have been working day and night on a new technology that they think can change the world: 3D printed human organs. At the time of this blog post in 2019 there are over 114,000 Americans on the waiting list for various organ transplants. And a shocking 20 people die every day waiting for available organs. Clearly the lack of handy organs is an incredibly pressing issue. This is why the work being done around the world to further push the boundaries of organ replication is so essential. But it begs the question, when can we expect this science to be widely available?

The History of Bioprinting

3D printing has come a long way since its humble beginnings in 1983. In the beginning 3D printing was only used to make plastic models of parts that would then be made from metal using more conventional methods. However as the years went on the potential for 3D printable materials has skyrocketed. It is now more than possible to 3D print extremely strong metal components and even entire bridges. Looking at the lengths 3D printing had come it was just another step forward to begin experimenting with printing biological material. At first scientists experimented with creating scaffolds in the shape of essential organs and covering them in specialized donor cells. This was effective in creating working organs, but scientists were not satisfied. They wanted to print using living bioink.

The problem with printing using live cells is that, like anything alive they need constant sources of water and nutrients. This problem gave rise to the invention of “Microgel“, a gelatin made from vitamin rich materials that is used to support the bioink both structurally and nutritionally. Bioprinters often have two printing heads, one for bionink and the other for micogrel.


The Benefits of Bioprinting?

Bioprinting is not only an incredible technological advancement, but also a huge money saver. It is estimated that with the rise of bioprinting organ transplant costs may see a drastic decrease. Today, a typical organ recipient is facing costs upwards of $300,000. With new competition from the bioprinting industry the simplicity and ease of creating suitable organs and performing procedures will greatly diminish the cost of treatment.

When Will Bioprinting See Widespread Use?

It is hard to say when man made organs will be all over the place, but there are significant advancements being made every day. For example the cornea, the essential exterior to the human eye, is an organ that is extremely close to being ready for practical use. With the use of a one of a kind bioink, researchers at New Castle University were able to produce a clear, circular disc that precisely resembles a cornea. This cornea, which can be printed in just 10 minutes, can be custom fit using a scan of the patients eye. Although more research is needed into the long term safety of a real life procedure, this goes to show that bioprinting is not technology of the distant future. The age of bioprinting is just around the corner.


In closing, bioprinting is in my opinion some of the most important scientific work being done right now. There is still much work to be done. But a future where any organ can be replicated in a lab and printed up on the spot is not as far away as it may seem. The progress being made day by day will quite possibly change the world forever. It will bring new hope to thousands and will save countless lives, but at what cost? Only time will tell.

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