Author Archives: Olivia Yang

Know Yourself Before Drinking Alcohol

Why after drinking, some people’s faces will turn red, while some of the others turn white?

Red face after drinking Alcohol   Source: Pixabay

Let’s talk about the reason for blushing first. Many people think this is caused by alcohol. But, it is instead caused by acetaldehyde. Acetaldehyde has the function of expanding the capillaries, and the dilation of the capillary of the face is the reason of blushing. So if some people drink and blush, it means that they can quickly convert ethanol into acetaldehyde, which indicates that they have efficient ethanol dehydrogenase to complete this conversion. Relatively, there is another enzyme called aldehyde dehydrogenase. People who drink with red face are because they only contain ethanol dehydrogenase enzyme, but not aldehyde dehydrogenase. Therefore, the body rapidly accumulates acetaldehyde and cannot metabolize. As a result, the red face may last for a long time. Generally, the red colour will disappear after one or two hours. This process depends on the cytochrome P450 in the liver that slowly converts acetaldehyde into acetic acid, and then goes into the Krebs cycle and be metabolized.

What about people who can drink a lot? Usually, for this kind people, the more they drink, the whiter their face are. For one thing, they will suddenly fall into a blind drunk degree. That is because the highly active ethanol dehydrogenase and acetaldehyde dehydrogenase are not presented simultaneously, mainly due to the slow oxidation of P450 in the liver. So, why are such kind people able to give others a feeling of they are “wine tanks” ? The reason is: they rely on inner body fluid to dilute alcohol. It suggests that the bigger they are, the more they can drink. Until alcohol levels exceed 0.1 percent, under normal circumstances, they will fall into a coma.

What happens if a person has a highly active alcohol dehydrogenase and a highly reactive acetaldehyde dehydrogenase? Then we can say that he/she is a “wine tank”! We can judge if a person is a wine tank or not by seeing if they will sweat profusely while drinking. Because if both enzymes are highly active, alcohol quickly becomes acetic acid into the Krebs cycle, then turn to heat and sweat in a very short time.

Alcohol conversion  Source: Wikimedia Commons

People who have a white face after drinking are more likely to injure their liver. They lack the signal of drinking baseline, so it is easy to drink beyond their ability, which makes them drunk. What’s more, the alcohol in their bodies accumulates in the absence of highly active enzymes, leading to liver damage.

Depending on the introduced after-drinking characteristics, it can help you understand your own drinking system. Drinking according to your physical condition is a good method to protect your personal health when enjoying alcohols.

-Olivia Yang-

Secrets in Firefly

Have you ever seen fireflies in your childhood? It’s hard to see them now, but I am still very interested in them.

Photo of firefly.

Why do fireflies shine?

The scientists found that the bioluminescence of the firefly’s abdomen has a small aperture of the luminescent layer. This luminous layer contains thousands of light emitting cells. In the light emitting cell, it contains two kinds of chemicals, one is called fluorescein, another kind is called luciferase. Fluorescein can react with oxygen in the air, release energy in form of photons and emit fluorescence in the catalysis of luciferase. In specific, magnesium and ATP combine with luciferase and the protein luciferin. This combination creates a very excited molecule. When oxygen is introduced into the mix, the excited molecule goes from excited state back to a stable state. This procedure releases energy and creates light. Therefore, firefly luminescence is caused by chemical reactions.

Specific bioluminescence reaction in fireflies.

Why do fireflies shine off and on?

The mechanism that turns on and off this light show is still the topic of some debate. The prevailing theory revolves around the firefly’s ability to control oxygen within trachea. When oxygen is abundant, the reaction is intense and the light is strong; When the oxygen is not sufficient, the reaction is slow, the light will be weak or even bleak. There is a high-energy compound called adenosine triphosphate (ATP) in fireflies, which, when the light is weak, more ATP will be released by Mitochondria (the organelle that controls ATP production), and interact with fluorescein, so fireflies can glow again.

Do fireflies burn themselves?

The lighting reaction released almost all the energy in form of light, only a few in the form of heat release, so the fireflies light belongs to cold light. Therefore, fireflies won’t burn themselves due to overheating. Fireflies are more than 95% efficient in making this cold light.

Fireflies and bionics

Firefly has many beautiful fluorescent colours, like light green, light red and pale blue. The difference in colours are highly related to the type of fluorescence in the body. According to this feature, scientists have developed many applications based on the luminescence mechanism of fireflies. In medical science, scientists extract fluorescein from fireflies and use it in the study of cancer cells. By observing the glow of fluorescein placed in cells, they are able to judge the growing speed and growing environment of cancer. In industry, water pollution can be monitored with the help of fluorescein. The luminescence mechanism can be used in more area, because it is very simple and effective. What’s more, there are already a considerable amount of applications of cold light source, such as the flashlight for underwater operation. Cold light source can greatly improve the efficiency of converting chemical energy into light energy, so it can be developed further and applied to other aspects in our life.

Fluorescence microscopy images of sun flares pathology in a blood cell showing the affected areas in red.

-Olivia Yang-

Who Takes the Responsibility of Food Coma?

We’ve all been there. After lunch, you are sitting in class with overwhelming drowsiness. This feeling has a terminology called “food coma” which is a state of drowsiness or lassitude following a meal. The reason that causes food coma has been studied for many years, and scientists are still researching it and having arguments.

Food coma after a meal.

A popular statement is that the food coma after eating is related to amount of carbohydrates in the meal. Meals that are high in carbohydrates cause an increase in the hormone insulin. The ensuing high level of insulin promotes large removal of the branched-chain amino acids by muscle, thereby lowering the plasma levels of these amino acids. As a result, the entry of branched-chain amino acids into the brain is reduced, while more tryptophan enters the brain. Tryptophan is a special amino acid that in the brain can be converted into a signalling chemical called serotonin. Serotonin is associated with feeling of  sleepiness and drowsiness. The more Serotonin existed in brain, the stronger drowsiness you will feel.

Pathway from Tryptophan to Serotonin. 

A study in fruit flies sleep patterns discovered that, just like us, they slept longer after large meals, and there were some foods that were much better at letting them sleep than others. The research also reveals that salty or protein-rich foods promote sleep, whereas sugary foods do not. In their experiment, feeding high-protein and large meals to the fruit flies caused them to sleep up to 40 minutes more than they usually would if they hadn’t eaten anything. And high-salt meals increased the fruit flies sleep period by nearly the same amount. High carbohydrate meals, however, did not change the flies’ sleep patterns in comparison with their sleep patterns after not eating. The researchers found that specific brain circuits are likely to cause the desire for post-feast naps. The food coma effect is weaker or stronger at a different time of the day. For the fruit flies, the effect is stronger in the morning than in the evening. This indicates that the body’s internal clock also plays a role in a time when we are most likely to feel sleepy after a meal, especially after lunch.

More research will be happening to study what is the major reason that causes food coma. It will then give us a direction on how to adjust our dietary habits for diminishing food coma after a meal. Hope that day will be coming soon!

-Olivia Yang-