AP Biology class blog for discussing current research in Biology

Tag: inhibitors

Serotonin: Costs & Benefits

This study concluded that serotonin may potentially accelerate a cardiac condition known as generative mitral regurgitation. DMR is one of the most common cardiac diseases. The left atrium and left ventricle of the heart are where the mitral valve is situated. When the heart contracts, it closes tightly to stop blood from flowing back into the left atrium. DMR can therefore result in symptoms including exhaustion and shortness of breath. The heart has to work harder as a result of the decreased circulation efficiency, which over time results in lasting harm. The deterioration of the mitral valve is now untreatable. 

Serotonin is involved in many bodily processes, including mood, digestion, sleep, memory, and blood coagulation. Your brain uses serotonin as a neurotransmitter to control mood; anxiety and depression are linked to low serotonin levels. A cell receives a signal from serotonin to function appropriately when it binds to particular receptors on the surface of the cell. Serotonin is transported into the cell by a protein called the serotonin transporter (SERT or 5-HTT), where it is reabsorbed and regenerated. 


Serotonin can stay available for longer lengths of time thanks to medications known as selective serotonin reuptake inhibitors (SSRIs), which bind to the SERT and decrease serotonin reuptake. Some examples of SSRIs are medications such as fluoxetine (Prozac) and sertraline (Zoloft). 

The study assessed 100 mitral valve samples and clinical data from over 9,000 patients who had undergone valve repair or replacement surgery for DMR. In analyzing the data of these patients, Ferrari and colleagues discovered that SSRI use was linked to severe mitral regurgitation that required surgery at a younger age than in those who did not take SSRIs.

ZOLOFT (sertraline HCI) Crop

Additionally, the researchers used normal and transgenic mice lacking the SERT gene to study in vivo mouse models. They found that normal mice treated with high doses of SSRIs also had thickened mitral valves, and that mice lacking the SERT gene similarly acquired thicker mitral valves. The researchers discovered genetic variations in the 5-HTTLPR region of the SERT gene that have an impact on SERT function using genetic analysis.

One thing we have learned this far in AP Biology is that a receptor is a protein that can bind to a molecule. Different receptors cause different effects in the cell. Receptors are specialized proteins found on the surface or inside cells that are able to recognize and respond to specific chemical signals, such as hormones, neurotransmitters, and other signaling molecules. These signals can trigger a range of cellular responses, including changes in gene expression, alterations in cellular metabolism, or changes in the electrical properties of cells. Receptors are essential for many physiological processes, including sensory perception, regulation of the nervous and endocrine systems, and immune responses. There are many different types of receptors, including ion channels, G protein-coupled receptors, and enzyme-linked receptors, each with their own unique structure and function.

Androgen receptor 3-d model

I think this is very interesting considering that people did not know that SSRI use led to severe mitral regurgitation. People had to have surgery at young age to fix this. Many individuals would not have had to go through with a medical procedure if they knew what was causing this. 

How Baby Kangaroos Are Helping Climate Change

In the world, there are over 1 billion cows and calves, roughly 4.3 times as many cows as people living in the United States. Cows are the number one source of greenhouse gases worldwide, with a single cow producing 220 pounds of methane gas a year. Methane (CH4) is a colorless, odorless, and highly flammable gas, composed of carbon and hydrogen. Being a potent greenhouse gas, it impacts climate change by increasing global warming according to the US Environmental Protection Agency. Methane affects our environment but it can also impact humans “high levels of methane can reduce the amount of oxygen breathed from the air. This can result in mood changes, slurred speech, vision problems, memory loss, nausea, vomiting, facial flushing, and headache. In severe cases, there may be changes in breathing and heart rate, balance problems, numbness, and unconsciousness“. Although this is in extreme cases. Recently, scientists may have discovered a methane inhibitor that could reduce the amount of methane cows release. This source comes from an interesting source though: Baby kangaroo feces.


It's a cowspiracy ! - Wake up and smell the methane. (23335965671)


Researchers from Washington State University wanted to figure out a solution to lower methane gas production rates in cows seeing as people enjoy eating red meat and taking them entirely out of the equation is not a feasible answer. They performed a study using baby kangaroo fecal matter to develop a microbial culture that inhibited methane production in a cow’s stomach stimulator. This resulted in cows producing acetic acid – is also known as ethanoic acid, ethylic acid, vinegar acid, and methane carboxylic acid; it has the chemical formula of CH3COOH. Acetic acid is a byproduct of fermentation and gives vinegar its characteristic odor. Vinegar is about 4-6% acetic acid in water – in place of methane. Acetic acid is not just a waste product in a cow like methane but is actually beneficial for the cow as it helps muscle growth. Not only would lowering rates of methane production in cows be beneficial for the environment but also for the cow as the cow wastes around 10% of its energy in methane production. Researchers have tried chemical inhibitors but the methane-producing bacteria has become resistant each time. The actual experiment all began with the researcher’s study of fermentation and anaerobic processes, which lead to the creation of an artificial lumen designed to stimulate cow digestion. Then they began investigating how they could outcompete the methane-producing bacteria and learned that – specifically – baby kangaroos have acetic acid-producing bacteria instead of methane-producing bacteria. Researchers were “unable to separate out specific bacteria that might be producing the acetic acid, the researchers used a stable mixed culture developed from the feces of the baby kangaroo.” Eventually, the acetic acid bacteria was able to replace the methane-producing microbes for several months having similar growth rates. Researchers hope to eventually test their system outside of a stimulated rumen and on a real cow sometime in the future. This connects to our unit of enzymes and enzyme inhibitors. Enzymes allow the cell to perform tasks with less energy by binding to reactant molecules and holding them in a way that breaks the chemical bond allowing bond-forming processes to take place more easily. Enzyme inhibitors are molecules that bind to the active site – competitive inhibition – or the allosteric site – noncompetitive inhibition – making the enzyme unbindable, reducing the rate of enzyme-catalyzed reaction, or preventing it from happening altogether. This is what the researchers are trying to do in their study, inhibit the enzyme in the methane-producing bacteria and allow the acetic acid bacteria to grow instead. Overall, if this process proves to work in real cows it could be a huge advancement in the slowing down of climate change.





Antitoxin Mechanism Saves Us From Virus Attacks!

Researchers in Lund have recently discovered an antitoxin mechanism that may be able to protect bacteria against virus attacks by neutralizing hundreds of toxins. Understanding this antitoxin mechanism, named the Panacea, could be the next step to the future success of phage therapy, a treatment for antibiotic resistant infections.

These toxin-antitoxin mechanisms are a kind of on-off switch in bacterial DNA genomes. They are found to attack bacteriophages to defend bacteria.This activation of toxins allows bacteria to “lockdown” and limit growth and spreading of a virus. In order for Phage therapy to be successful in the future, it is important to understand these mechanisms in great depth. The goal of Phage therapy is to use viruses to treat bacterial infections. A toxin dramatically inhibits bacterial growth and an adjacent gene encoding an antitoxin counteracts the toxic effect. Although toxin-antitoxin pairs have been associated with new toxins or antitoxins before, the ability of the Panacea is unprecedented.

Phage therapy

As research continues on toxin-antitoxin systems and phage therapy it is clear that what we know is just the tip of the iceberg. As bacteria increasingly become resistant to antibiotics, other approaches are needed to help eliminate infections. The next steps of this research is to continue deepening the understanding of the Panacea and finding toxin-antitoxin systems on a universal scale.

In AP biology class we learned about inhibitors. An inhibitor is something that slows down or prevents a particular reaction or process. A toxin inhibits bacteria from growing and reproducing so the antitoxin can act against the virus that has already spread.

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