The Common Types of Chemical Reactions
In our daily life, we encounter a number of chemical reactions, although we may not always think of the chemistry hidden within those principles. The mere melting of an ice cube kept in a glass, boiling of water, burning of wood, smoke ejecting from vehicles – all are classic examples of common chemical reactions in our daily lives. In middle and high school chemistry, students are introduced to a large number of reactions. Students must understand that most of the chemical reactions follow a certain order. So instead of just memorizing individual reactions, it is better to understand the way each group of reactions proceed to form desired products. That will make it easier for students to predict the products of a reaction in several other cases of chemical reactions.
Examples of Common Chemical Reactions in Chemistry
Every natural process is an example of a chemical reaction. A battery converts chemical energy into electrical energy, by following some specific reaction. Similarly, burning of a log of a wood, in the presence of oxygen is another reaction leading to products like carbon dioxide and heat energy. Some more common chemical reactions examples have been discussed further.
Synthesis or Combination Reaction
This is the simplest reaction that occurs in nature. When two or more chemical elements or compounds react to form some specific product(s), it is called synthesis. It is in of the form: A + B → AB
Examples Read the rest of this entry »
What is Fermentation?
Do you know what is common between curd, wine and beer? They are all formed by the process of fermentation. But what is fermentation? A simple fermentation definition can be: the process of breaking down of complex substances into a simpler form. The history of fermentation is very old. The process of fermentation was used in making beverages such as beer and wine, since as early as the year 7000 BC. Later on, the process was used to make many milk products like curd and cheese. The science of fermentation is known as zymology, and Louis Pasture was the first zymologist who is known for his research on yeast and the fermentation process. So let’s find some more information on the fermentation process in the following paragraphs.
What is Fermentation in Biology?
In biology, the fermentation process is actually a conversion of sugar into acids or alcohol with the help of bacteria or yeast. The bacteria help in the conversion of sugar into acid, and the yeast is used for the alcohol production. Many people wonder, is fermentation aerobic or anaerobic? The answer to this is that fermentation takes place in anaerobic conditions or in the absence of oxygen. The process of fermentation initially resembles the process of glycolysis. In the first step of glycolysis, glucose is broken down into pyruvic acid, ATP and NADH. After this process the NADH is further re-oxidized and CO2 and the end product which can be either alcohol or acid, depending upon the organism performing the fermentation process, is released. So, we can say that fermentation is a chemical process.
Fermentation Examples
Following are some examples of fermentation, which will help you to understand the process and uses of it.
Beer is one of the best examples of anaerobic fermentation. It is made out of grains like wheat, barley, etc. The grain is dried and then mashed properly. This is then mixed with hot water. Then this mixture is kept in a fermentation vessel and then yeast is added. The vessel is then left for a few weeks in anaerobic conditions. In this condition, the yeast eats the sugar or carbohydrates and forms alcohol. After a considerable period of time, the beer is taken out from the vessels, filtered and then packed in the bottles. Read the rest of this entry »
Patterns of Evolution
I do not believe any branch of science has ever given rise to as many controversies and controversial debates as evolution has. But even with so many controversies, “Nothing in biology makes sense except in the light of evolution” (Theodosius Dobzhansky). When we think of evolution, the first name to strike even someone who is not from a biological sciences background would be Charles Darwin. Not a word can be written on evolution without mentioning the name of this pioneering evolutionary biologist. His work On the Origin of Species has been the topic of much discussion ever since it was first published.
Of the many concepts that were elaborated in this book (like survival of the fittest) one was Darwin’s Principle of Divergence. The other term – Convergent Evolution – is often regarded as the opposite of Divergence. However, convergent evolution was only a play of words that evolutionary biologists came up with to explain one of their many observations; it has got nothing to do with divergence as such. Here is a brief account of convergent evolution vs. divergent evolution. However, for the ease of understanding, I will first explain divergent evolution and then move onto convergent evolution.
Divergent Evolution
Imagine evolution of life to be a process like the flowing of a river. As it leaves the mountain, it will take its due course and meander about. If a boulder were to obstruct its flow into a crevice, it would take a turn around the crevice. If however a big enough boulder were to stand in between its path, the river would split into two and give rise to two new smaller rivers, each of which would meet its separate fates as it flowed down the mountain.
This is exactly what divergent evolution is all about. The boulder represents something known as ‘natural selection’. Natural selection is more of an outcome of natural pressure that organisms find themselves subject to (typically pressure of competition, pressure of mating preferences of (usually) the females of the species, etc.) rather than the actual pressure. It is the result rather than the process. However, it is now interchangeably used as cause and effect. Read the rest of this entry »