AP Biology class blog for discussing current research in Biology

Tag: Glucose

Our Appetite Uncovered

Researchers in Korea have just taken a major step in the journey towards understanding the patterns of our eating behavior. Scientists at the Daegu Gyeongbuk Institute of Science and Technology have recently discovered the dynamics of the enzyme in our brains that controls our appetite.


Previous research has uncovered that the hypothalamus region in our brain detects levels of glucose and hormones in our blood in order to manage our food intake. To extend these findings, the recent research done in Korea has shown that having low amounts of glucose in the bloodstream activates an enzyme, called adenosine monophosphate-activated protein kinase (AMPK). This enzyme alters the properties of neuropeptides, small protein molecules used by neurons to communicate with each other, using autophagy.

Copyright Nevit Dilmen

Credit Nevit Dilmen

How it Works

When decreased amounts of glucose in the bloodstream are detected, AMPK is stimulated, which diminished the levels of two neurohormones in the brain, neuropeptide Y (NPY) and pro-opiomelanocortin-alpha (POMC). The levels of NPY and POMC are reduced by the process of autophagy, the natural self-destruction mechanism in the body. Decreased amounts of NPY and POMC have been strongly linked to an increase in food intake and obesity.


Research Methods

In orders to trace the complex pathways between the brain and the body to come to these conclusions, researchers conducted experiments using cell lines in vitro and mice. Using the cell lines, researchers were able to record the presence of autophagy under different levels of glucose and activated certain pathways to find the links between the brain and the body. In the mice, researchers injected a virus that eliminated AMPK in the mice’s brains. As a result, the mice ate significantly less than others not injected with the virus.


Combining the results from the cell and mice experiments confirmed that AMPK altered the levels of NPY and POMC, therefore affecting one’s appetite. While these findings are preliminary, they are a significant step in the direction towards completely understanding our eating behavior and may one day lead to solving the obesity epidemic we face today.


More Info:

Sugar Motivates You.

Dumdums by Linuxerist

A study from a few years ago created a theory called The Energy Model of Self Control. This stated that willpower lessens as your brain lacks sugars, that it previously used for provious exertions. Basically, once you perform a task that requires motivation, you will have a harder time completing the following task that requires motivation, because you have used up the sugars that allow you motivate yourself.

Daniel Molden, a scientist from Nothwestern University, was skeptical of such claims. He recently recreated the study and used more technologically advanced machines, to measure the results. What he found was that the claim that once you perform a task that requires willpower, you will have a harder time to perform the following task that demands that same. He then challenged that “acts of self-control lower blood glucose levels.” After performing a self motivated task, volunteers rinse with either a sugar-water solution or an artificial sugar-water solution. In the previous research, subjects had to eat or drink sugar, to experience the effects. The results showed that participants that rinsed with the real sugar-water solution were able to motivate themselves for the next task, whereas volunteers that rinsed with what tasted like a sugar-water solution, but actually contained no sugar, were not able to self-motivate themselves. The results also showed that the sugar didn’t need to be metabolized, as the results were immediate. Molden and partners have concluded that the mouth can register the presence of carbohydrates in the solution and then signals the brain that energy is coming. The dopamine system motivates the brain to work harder. “In short, the sugar motivates — rather than fuels — willpower.”  These scientists have decided that self-control is a lack of motivation, and can be restored with a simple sugar rinse.

Different things motivate different people, some people just need a goal and they’ll do whatever it takes to reach it. I myself am very bad at motivating myself todo work and have no self-control to see to it that I complete what needs to be done. For a person like me, this is very interesting, and something I will definitely try in the future! Will you try rinsing your mouth with sugar and water to keep yourself motivated?

Photo: CC Liscensed photo by Linuxerist

New Ways to Combat Cancer

Rights Glucose Biomass Conversion

Rights Glucose Biomass Conversion

What if I told you that one of the newest cancer treatment research methods had to do with glucose?  Glucose is the basic unit practically all food is broken down into, and is used as an energy supply.  By preventing cancerous cells from accessing glucose, could we kill them off?

This idea is being extensively researched, as scientists have discovered that whereas normal cells use the form of the enzyme pyruvate kinase known as PKM1 to utilize glucose, cancer cells use PKM2.  Furthermore, studies have shown that PKM2 was inhibited by the presence of oxidants. In the presence of oxidants, PKM2 does not function properly, causing the cancerous cell to fail to be able to break down glucose into ATP through cellular respiration.  Without an energy source, cancerous cells would be unable to form metabolic functions, causing them to die before they divide and spread.

Pyruvate kinase is an enzyme involved in glycolysis, and catalyzes the transfer of a phosphate group from phosphoenolpyruvate (PEP) to ADP.  This process creates one molecule of pyruvate and one molecule of ATP.

For more information on this technique, check out this link:


Also, for more information on PKM2, check out: 

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