F.A.T.S!

Have you ever been call as a fat ass? fatty boom boom?


Do you know there's saturated fats and unsaturated fats?
Well, this is all about fats!

Fats and oils are belong to a group of naturally occurring substances called lipids. Lipids are a group of organic compounds that make up the structure of cells found in plant and animal tissues. The lipids are water insoluble compounds by using organic solvent such as esther and benzene.

Fats and oil are chemically very similar, but differ in their physical states. Fats normally found in animals like goats and cows. It is in solid state at room temperature such as butter and tallow. Whereas fats from plants are in liquid states known as oils.The example of vegetable oil such as palm oil, coconut oil, olive oil,soybean oil and corn oil.

Basically fats and oils consist of a variety of long chain carboxylic acid called fatty acids with alcohol propane-1,2,3-triol(known as glycerol).


Fatty acids are long straight-chain carboxylic acid and a molecule of glycerol may combine with one two or three fatty acids to form monoester,diester or triester.


Hence fatty acid playing the main role determining whether it is saturated fats or unsaturated fats. A saturated fatty acid has all carbon atoms joined together by carbon-carbon single bonds. Palmitic acid is a saturated fatty acid. In an unsaturated fatty acid, the carbon chain has one or more carbon-carbon double bonds. Monosaturated is formed if the fatty acid molecule has one carbon-carbon double bond


whereas polyunsaturated has more than one carbon-carbon double bond.

Fats which contain esters of glycerol and unsaturated fatty acids are classified as unsaturated fats. Example like plants or vegetable oils contain a large proportion of unsaturated esters.Thus, it has lower melting points.



In other words,fats which contain esters if glycerol and saturated fatty acids are classified as saturated fats. It containing a large proportion of saturated esters tend to have melting points and are solids at room temperature. Medical research has found that a diet high in animal fats, particularly saturated fats is considered unhealthy. High consumption of food high in saturated fats is likely to result in obesity. It is also found that animal saturated fats pose a greater risk for coronary heart disease and strokes than unsaturated vegetable oils. Hence, unsaturated fats are more favorable and healthier than saturated fats.



Therefore, chemist developed an idea to convert unsaturated fats to saturated fats through a process call hydrogenation. Each carbon-carbon double bond absorbs one mole of hydrogen. The hydrogenation process is carried out by bubbling hyrogen gas through hot liquid oil in the presence of fine particles of nickel catalyst. A temperature of about 200C and pressure about 4 atm are used. As more and more of double bonds get hydrogenated, the relative molecular mass of the oil molecule increases. And causes the Intermolecular forces become stronger and more energy is need to overcome them. As a result, the boiling point of the oil increases and the physical state changes from liquid to solid.





Margarine is an example or products produce through hydrogenation. It is a soft solid with low melting point at room temperature. It is made by hydrogenating some of the carbon-carbon double bonds in polyunsaturated vegetable oil such as palm oil and sunflower oil. If you were to compare butter and margarine, which is better for health. I would assure you that margarine is healthier than butter because margarine is made from vegetable oil, is low in saturated fat and has no dietary cholesterol.
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In a conclusion, vegetable oils do not contain cholesterol because only animals would make cholesterol. These unsaturated fats do not have the damaging effect of saturated fats to cause cardiovascular problems. The sentence only can conclude that we are suggested to consume unsaturated fats than saturated but doesn't means that we can consume unsaturated fats in large quantities. Too much of fats consumption, whether unsaturated or saturated will make us overweight. A balanced healthy diet will keep the vital processes in our bodies to function efficiently to maintain a healthy body.

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Synthetic Polymers

Let's just begin with a question.What is polymers?

Polymers are long-chain molecules formed bu joining together thousands of monomers(small repeating units). A polymer is molecule is synthesis in a process call polymerisation by joining together the monomers molecules. Besides synthetic polymers, natural polymers are exists and found in living things. For example, protein, DNA, cellulose, starch and natural rubber.
Well, this post are going to concentrate on synthetic polymers which is so called man-made polymers. They include plastics such as polyethylene and fibres such as nylons.

For example plastics are the largest group of synthetic polymers which have the important property of being easily formed. The raw materials to make plastics came from the products of cracking of petroleum fractions. The monomers of making plastics polymers is alkenes, they are formed by addition reaction. Polythene , polyvinyl chloride (PVC) , polypropene and perpex are the example of plastics.

Polythene also known as polyethene.

The monomers for is ethene.


The polymerisation process produces polyethene.

Polypropene


and its monomers propene


Both of this polymers are used o make plastic bags,pipes, containers moulded objects and toys.

Polythene , polyvinyl chloride (PVC)


the monomer, chloroethene.

The reaction to form polychloroethene is shown below.


PVC is normally used to make pipes, wire and cables,records and apparels such as footwear and rain coats.



Perspex

The monomer is Methyl 2-methylpropenoate.

Polymerising this monomer will produce the polymer methyl2-methypropenate. It is used to replace glass, fibre optics and illuminated signs.

Besides plastics , there are two important groups of fibres polyamide which is nylon and polyester which is terylene. Both nylon and terylene are produced by condensation polymerisation.

Nylon


Nylon is used to make textile fibres, threads, ropes, toothbrushes and electrical insulators.

Terylene.
A condesation reaction will join thousands of diacids and diols together to produce polyester.

Terylene is used to make textile fibres, parachutes, stockings, fishing nets and tapes.

Synthetic polymers are usually cheaper than natural materials and it can be tailor-made by chemists to suit certain specifications.Synthetic polymers vary widely in physical such as strength, flexibility, resistance to chemical attacks and softening temperature.
For the last fifty years or so, the development of synthetic polymers has led to a great change in the world where we live. Many materials of great usefulness are developed. The manufacture and use of synthetic polymers have increase rapidly over the years. And they are steadily replacing traditional natural materials. Plastic chairs and tables are replacing wooden ones; PVC is replacing leather in sofas; nylons and terylene is replacing natural wool and cotton.

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Let it snow..

Ever since I was born, I always dream that it would snow in Malaysia one day. When day goes by, people are growing up mentally and physically and then we started to realize that it never snow where we live. Oh well, I still wish to touch the snow. I want to feel it on my cheeks, build a snowman on a snow land instead of building the sandcastle on the beach and throw a snowball at someone's face. I don't mind I'll get frost bitten, I just wish I could travel overseas and learn how to run in the snow.

During Christmas, it is traditional to decorate every places with lights and sometimes with illuminated snowflake, snowmen and other Christmas figures. I remember I've seen snowflakes the most because snowflakes are one of the most recognizable and endearing symbols of winter. It has it's delicate shape and it happens in real. Hence, I did some research about snowflakes.
There you go..

In western country where you will see snowflakes are particular form of water ice.Snowflakes form in clouds, which consist of water vapor.When the temperature decreases water freeze to become ice. And there's where science kicks in. There are several factors affect snowflake formation such as temperature, air currents, and humidity which are all influence their shape and size. Water might get mixed up with dirt and dust particles and affect crystal weight and durability.
Snowflake formation is a dynamic process.First, the tiny ice crystal becomes hexagonal (six-sided). This shape originates from the chemistry of the water molecule, which consists of two hydrogen atoms bonded to an oxygen atom. The water molecules in a snowflake chemically bond to each other to form the six-sided flake due to the angle of the water molecule and its hydrogen-bonding, . The flake eventually sprouts six tiny branches. Each of these branches grows to form side branches in a direction and shape that are influenced by the clustering of water molecules on the ice crystal surfaces.

Researchers show that not all snowflakes are symmetrical. Changes in temperatures, presence of dirt, and other factors may cause a snowflake to be lop-sided. Yet it is true that many snowflakes are same in all side and intricate. This is because a snowflake's shape reflects the internal order of the water molecules. Ice and snow as water molecules in the solid state, form weak bonds (called hydrogen bonds) with one another. These ordered arrangements result in the symmetrical, hexagonal shape of the snowflake. During crystallization, the water molecules align themselves to maximize attractive forces and minimize repulsive forces. Consequently, water molecules simply arrange themselves to fit the spaces and maintain symmetry.

However, there's no snowflakes are alike due to the precise number of water molecules, spin of electrons, isotope abundance of hydrogen and oxygen, etc. But sometimes it is possible for two snowflakes to look exactly identical and any given snowflake probably has had a good match at some point in history. Anyhow, it is improbable that anyone would see two identical snowflakes since there are so many factors affect the structure of a snowflake.

And lastly, are you wondering why snow is white?I'm gonna tell you why.
During the formation of snowflakes, water droplets in cloud are saturated with dissolved gases. When the environment temperature decrease until freezing point, insoluble gases in snow are trapped inside and form tiny bubble. The size and the distribution of the tiny bubble are quite uniform due to small droplet size and fast freezing rate. Visible light are reflected by tiny bubble ; and because snowflakes have so many light-reflecting surfaces they scatter the light into all of its colors, so snow appears white.

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