Tuesday, January 25, 2011


Q: Why do chemists like nitrates so much?
A: They're cheaper than day rates.
Why do onions make you cry?

Who has never cried while cutting an onion? (well, apart from those who have never cut one hehehe). This is a little explanation in easy terms.

Inside the onion cells there are some chemical compounds that contain sulfur. When you cut an onion its cells are broken and those chemical compounds then undergo a reaction that transforms them into a more volatile sulfured products, which are released into the air.

These sulfured compounds react with the moisture in your eyes forming sulfuric acid, which produces a burning sensation. The nerve endings in your eyes are very sensitive and so they pick up on this irritation. The brain reacts by telling your tear ducts to produce more water, to dilute the irritating acid. So you cry to keep your eyes protected from the acid.

There are some tricks to make onion-dicing less problematic:
- Chop the onion under cold water. The volatile sulfured compounds will be released but then they react with the water, instead of reaching your eyes.
- You can freeze the onion for 10 minutes before cutting it. The cold temperature of the onion will slow down the chemical reaction which forms the volatile sulfured compunds.


The Medicines, which is very important for the prevention and cure of the dangerous diseases is a made of various chemicals having curative effect. Chemotherapy use for treating cancer patients is one of the common examples. Chemistry is combined with the biology to produce a branch biochemistry which has made immense contribution to our daily life. Our body itself is made up of various chemicals, the hormones; enzymes, etc are actually chemicals.
Beside many advantages it also has several disadvantages. When used irresponsibly or use in larger extent chemistry can cause harm to our life. The various poisonous gases from the automobiles, factories and many other factors have created a nuisance in the society.

Sunday, January 23, 2011


FUNNY HA.......

A neutron walks into a bar, sits down and asks for a drink. Finishing, the neutron asks "How much?"
The bartender says, "For you, no charge."

[Explanation for non-chemists: a neutron is a particle that has no charge. Proton are those with positive charge, and electrons those with negative charge.]


Why coffee keeps you awake?

It is well-known that the effect of coffee on mood is related to its content in caffeine, but why caffeine has such a strong effect on us? Caffeine operates using the same mechanisms of amphetamines, cocaine, and heroin to stimulate the brain, though with milder effects. It manipulates the same channels as the other drugs, and that is one of the things that give caffeine its addictive qualities. There is a chemical in our brain called adenosine that binds to certain receptors and slows down nerve cell activity when we are sleeping. To a nerve cell, caffeine looks like adenosine and it binds to the adenosine receptors. However, as it's not really adenosine, it doesn't slow down the cell's activity like adenosine would. So the cell cannot "see" adenosine anymore because caffeine has taken up all the receptors adenosine binds to. Then, instead of slowing down because of the adenosine level, the cells speed up.
The pituitary gland sees all of this activity and thinks some sort of emergency must be occurring, so it releases hormones that tell the adrenal glands to produce adrenaline. Adrenaline is the "fight" hormone, and it makes your heart to beat faster, the breathing tubes to open up, the liver to release sugar into the bloodstream for extra energy and your muscles to tighten up, ready for action. Because of this, after consuming a big cup of coffee your muscles tense up, you feel excited and you can feel your heart beat increasing. Moreover, as amphetamines, caffeine also increases the levels of dopamine, which is associated with the pleasure system of the brain, providing feelings of enjoyment and reinforcement.

Saturday, January 22, 2011

Chemistry in cigarettes
Cigarettes and other forms of tobacco consist of dried tobacco leaves, and other ingredients added for flavor and other properties.

Why smoking causes cancer? It's because tobacco and tobacco smoke contain more than 60 carcinogenic compounds. In general, more than 4,000 individual substances have been identified in tobacco smoke, including carbon monoxide, hydrogen cyanide, ammonia and other highly toxic irritants. Besides all the harmful effects of tobacco, it is addictive, and this explains why although 70% of smokers want to quit and 35% attempt to quit each year, fewer than 7% succeed. And the main reason why tobacco becomes addictive is due to its content of nicotine, which alters brain functioning.
Nicotine is a naturally occurring liquid alkaloid. An alkaloid is an organic compound made out of carbon, hydrogen, nitrogen and sometimes oxygen. These chemicals have potent effects on the human body. For example, many people enjoy the stimulating effects of another alkaloid, caffeine.

When you smoke, nicotine is absorbed through the skin and mucosal lining of the mouth and nose or by inhalation in the lungs. Once in the body, it activates the same reward system as do other drugs such as cocaine or amphetamine, although to a lesser degree. In the brain, nicotine increases the level of the neurotransmitter dopamine, which is a chemical in the brain responsible for feelings of pleasure. The acute effects of nicotine subside within minutes, so people continue dosing themselves frequently throughout the day to maintain the pleasurable effects of nicotine and to prevent withdrawal symptoms.