Preparation of Chloroform (CHCL3)

REQUIRED MATERIALS:
 - A glass tumbler or container
 - A syringe or similar
 - 10ml of acetone
 - at least 500ml of household bleach (NaCLO)

PROCESS:
  1. Start pouring bleach solution of required above mentioned volume on a glass container.
  2. Then after pour 10ml of acetone of glass container using syringe or similar.
  3. Place the mix in a dark cool place (not inside)
 Now, let react for a couple of hours. Then, after chloroform is prepared.

WARNING:
  If you are using industrial bleach then use only 200ml because  it is three times more concentrated than household bleach. Chloroform usually contains an amount of very toxic phosygene, formed upon contact with (O2) oxygen and light. Chloroform has strong narcotic properties so, avoid breathing on fumes. Stay safe take care and enjoy every experiments of science.
Taking this experiment as a play may really cause a great loss or damage of life and property because sodium metal is really very explosive when it contacts with moist and water directly and can cause a fire. So, it is better to carry out this experiment outside the houses or schools. Recommended place for carrying out this experiment is at safe experimental laboratories or at open and vacant places . Always be careful while making Na Metal. Being safe and doing safe is best method to learn each and every experiments of Chemistry Science.
With best wishes!
                                                                                            Administrative of blog: Bikash Pokharel

DNA (Deoxyribo Nucleic Acid)

Double helical structure of DNA molecule:

                  DNA is mainly found in the nucleus. A small amount of DNA is also found in mitochondria and   chloroplast. It a macromolecule formed by the end to end polymerization of a large number of repeated units called deoxyribonucleotides or simply nucleotides.

Each nucleotide is formed by cross-linking of three substances:

                                     i.            Deoxyribose Sugar: The DNA molecules contain deoxyribose sugar and hence, it is       called deoxyribo nucleic acid. Deoxyribose is a pentose sugar (with 5-carbon atoms).

                                     ii.            Phosphate: The phosphate in the DNA is present as phosphoric acid (H₃PO₄). Each   phosphate group is joined to a carbon atom 3’ of one deoxyribose sugar and to carbon atom 5’ of another deoxyribose sugar.

                                     iii.            Nitrogenous Bases: The nitrogenous bases are of two types: Purine and Pyrimidine.

a)      Purine: It is a double ringed structure. It contains Adenine (A) and Guanine (G).

b)      Pyrimidine: It is a single ringed structure. It contains Cytosine (C) and Thymine (T).

Nucleotides and nucleosides:

A sugar molecule with nitrogenous base forms a nucleotide. The nucleosides in DNA are called deoxyribonucleosides and nucleotides are called deoxyribonucleotides.

Nitrogenous base + sugar= Nucleoside

Nucleoside + phosphate= Nucleotide

Or

Nitrogenous base + sugar +phosphate= Nucleotide

DNA is a double helix or double stranded structures. By definition of a helix:
Double helix: The structure of DNA with the two strands of DNA spiraling about one other.
The double helix looks something like an immensely long ladder twisted into a helix, or coil. The sides of the "ladder" are formed by a backbone of sugar and phosphate molecules, and the "rungs" consist of nucleotide bases joined weakly in the middle by hydrogen bonds.

How 'obesity gene' makes people fat

Scientists have reveled how a gene long associated with obesity makes people fat by triggering increased hunger, opening up potential new ways to fight a growing global health problem. A common variation in the FTO gene affects one in six of the population, making them 70 percent more likely to become obese- but until now experts did not know why.
       Using a series of tests, a British -led research team said they had found that people with the variation not only had higher levels of the 'hunger hormone' ghrelin in their blood but also increased sensitivity to the chemicals in their brains. "It's a double hit." said Rachel Batterham from University College, London, who led the study, which was published in the Journal of Clinical Investigation today. The discovery follows the studies of blood samples from the people after meals, combined with functional magnetic resonance imaging  of volunteers' brains and cell-based studies looking at ghrelin production at a molecular level.
     

 Batterham said the work provided new insights and possible new leads for treatment, since some experimental drugs are known to suppress ghrelin and could be particularly effective if targeted at patients with the obesity-risk variant of the gene. Previous research has also shown that ghrelin can be reduced by eating a high- protein diet.At least 2.8 millions adults die each year as a result of being overweight or obese and more than 40 million children under the age of five were overweight in 2011, according to the World Health Organization (WHO).
So, developing effective obesity drugs has been a challenge for drugmakers, although some new medicines are now coming through.
       

Electromagnetic waves along with thier properties

A wave motion refers to a carrier medium of energy from one particular point to another without there being any kind of transfer of any matters between these two points. Waves may be classified as being either mechanical or electromagnetic. A mechanical wave is the disturbance that requires a material medium for it's propagation, e.g., water waves, waves in stretched strings, etc. It is also known as elastic waves. The electromagnetic waves are the waves in which the various of electric and magnetic filed take place during their propagation, e.g., visible light rays, x-rays, gamma-rays, radio waves, etc. They can travel through a vacuum. The solar radiation which we receive everyday is also electromagnetic waves.
       Infrared radiation, visible light and ultraviolet radiation are all members of the same electromagnetic spectrum. Some common properties of electromagnetic waves are as follows:
1. All electromagnetic waves travel through a medium or in a vacuum at the same speed i.e., 3*10^8 ms-1.
2. They are unaffected by electric and magnetic fields.
3. They are transverse wave.
4. The wave equation "speed= frequency*wavelength" can be applied.
5. They all, under suitable conditions, can be reflected, refracted and diffracted.
                                            They are characterized by their different frequencies (or wavelengths). Ultraviolet radiation has a greater  frequency than visible light and infrared has a lower frequency than visible light.