Thursday 14 January 2016

Instructions for Construction

Architects, engineers and designers refer to a blueprint when they are constructing something. A blueprint is a technical drawing that has all the details of what and how something is constructed.

Now, how about the human body? Where is all the information about what our bodies need to do stored
Each cell in our body has its own job. Some cells help us detect light and see, other cells carry oxygen around, while some cells help us digest food by secreting enzymes. There are over 200 cell types in the body - that is 200 different jobs!

But how does each cell know what job to do? Our cells are told what to do by a very special molecule called DNA, which is like a blueprint. DNA is shaped like a twisted ladder, called the double helix. The letters of the DNA, called bases, make up the rungs, whereas special sugars and other atoms make up the handrail. The rungs are very special. Each one has a name, but they are usually referred to by their initials: A, T, C and G. A good way of looking at it is that A, T, G and C are like jigsaw pieces. A and T fit together, C and G fit together - you cannot force a jigsaw piece to fit with a wrong piece!

Think of all the words you can spell. Each word is made using the same selection of letters. Depending on how we arrange the letters of the alphabet we can make new words. The same is true in the four letter alphabet of DNA. These letters form a sentence, and each sentence tells a cell to make a special molecule called a protein. These proteins in turn, are like little tiny workers scurrying about in the cell transporting other molecules, rearranging molecules, repairing the cell, getting rid of wastes, making the cell move, and also, constructing newer cells. 

Experiment: To extract DNA from an onion

distilled water, baking soda, salt, shampoo, ethanol, onion, and a sieve.

1. Prepare the buffer solution by mixing a bottleful of water with a teaspoon of salt, 3 teaspoons of baking soda, and 3 teaspoons of shampoo. 
2. Keep this buffer solution in a refrigerator.
3. Next, take an onion and mince it to pieces, or crush it with a blender.
4. Collect the pulp in a tall glass container.
5. Take a tablespoon of the mashed up onion and mix it with the chilled buffer solution. Stir it for 3 minutes and then leave it in the freezer for 5 minutes.
6. Remove the bits and pieces of onion by filtering it through a sieve. You now have a solution.
7. Slowly add cold ethanol to the solution by trickling it down the sides of the tall glass container.
8. The DNA will appear as a white cloud, which can be removed with a toothpick.

Glossary of terms:
Protein [proh-teen] - organic molecules constituting a large portion of the mass of every life form and necessary in the diet of all animals. 
Enzymes [en-zahym] – any of various proteins producing certain chemical changes by catalytic action.

Shared by Surain A. Victor
Guest Blogger

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