Fats

Between the food commercials you see on TV every day and the many nutrition bulletins and reports you hear about on the news every night, you get a huge amount of information about the fats that you eat. For example, you have probably heard of the following terms:
Saturated fat
Unsaturated fat
Polyunsaturated fat
Mono-unsaturated fat
Fatty acids
Essential fatty acids
Trans fatty acids
Omega-3 and omega-6 fatty acids
Partially hydrogenated fat
Have you ever wondered what it all means, or why it matters? Why can't we just eat, drink and be merry? In this article, you'll find out exactly what these terms mean and how the various forms of fat you find in foods affect your body.

What is Fat?Corn Oil
With some grains and nuts it is very easy to see where the oil comes from. For example, if you squeeze a sesame seed or a sunflower seed between two sheets of paper, you can see the oil. Corn isn't quite that oily, but it does contain oil. A kernel of corn has an outer husk surrounding a white or yellow starchy substance. At the core of the starchy substance and toward the pointy end of the kernel is the germ. The germ contains a small amount of oil. If you cut a popcorn kernel in half, you can see the husk, starch and germ. If you cut out the tiny piece of germ and squeeze the germ on a piece of paper, you will see the oil!

We see pure fats in three places at the grocery store:
In the vegetable oil aisle you see oils created from different seeds and nuts. There is corn oil, safflower oil, peanut oil, canola oil, olive oil... All seeds and nuts contain some amount of oil, because oil is a very good way to store energy. By the way, the only difference between oil and fat is whether or not it is a solid at room temperature.
In the meat aisle, you can look at different cuts of meat and see them outlined by a layer of white, solid fat created by the animal to store energy.
In the dairy aisle you see butter and margarine -- fat made from cream or vegetable oils, respectively.
The rest of the grocery store is, of course, filled with fats and oils, although they are less obvious. Potato chips and french fries are cooked in oil, cookies and cakes contain fats and oils, and so on. This is how we come to eat the fat we need every day. And we do need fat - as you will learn below, there are certain fats that we must have to survive.

So what are these fats and oils really made of? Well, if you really want to understand fat you need to study a little bit of chemistry. To talk about fat, we need to start by talking about fatty acids.

A fatty acid is a long hydrocarbon chain capped by a carboxyl group (COOH). There are many common fatty acids that you hear about, four of which are shown below along with acetic acid for comparison:



The COOH cap is what makes these molecules acids. You are probably familiar with acetic acid because this is the acid found in vinegar. You can see that the fatty acids are like acetic acid, but they have much longer carbon chains.

To make a normal fat, you take three fatty acids and bond them together with glycerol to form a triglyceride, like this:



Since this particular triglyceride happens to contain three molecules of stearic acid, it is also known as tristearin. This diagram shows one fat molecule. When you eat fat, you are eating collections of molecules like these. The choice of the fatty acids in the fat controls many different things about the fat, including how it looks, whether it is a solid or a liquid at room temperature and how healthy it is for your body.

Saturated vs. Unsaturated
If you look at palmitic acid and stearic acid in the first figure, you can see that the carbon chains are completely and evenly filled with hydrogen atoms. In other words, the chains are saturated with hydrogen. Fats (triglycerides) that contain palmitic acid and stearic acid are therefore known as saturated fats. Fats made up of saturated fatty acids are solid at room temperature.

In the first figure, you can see that oleic acid is not saturated. Two of the carbons are connected by a double bond, and two of the hydrogens are missing. This fatty acid is unsaturated. Fats that have a lot of oleic acid in them are liquid at room temperature, and are therefore known to us as oils.

Oleic acid, because it contains one double bond, is also referred to as mono-unsaturated. Fatty acids that have multiple double bonds, like linoleic acid in the first figure, are called polyunsaturated. Polyunsaturated fats are also liquid at room temperature.

If you have a bottle of corn oil, what you have is a bottle of polyunsaturated oil with a high concentration of linoleic acid. Because it is polyunsaturated, it is liquid at room temperature. If you would like to solidify it and turn it into margarine, what you do is hydrogenate it. That is, you saturate it with hydrogen by breaking the carbon double bonds and attaching hydrogen. To do this, you heat the oil and add pressurized hydrogen gas and a nickel catalyst. In this way, you create "partially hydrogenated vegetable oil." PHVO is the main ingredient in things like vegetable shortening and margarine.

Fat and Health
Most of the nutrition science you hear about right now points to mono-unsaturated fats as the good fats. Olive oil and canola oil are both mono-unsaturated. Mono-unsaturated fats are thought to lower cholesterol.

In general, the fats to steer clear of are the saturated fats. Saturated fats are bad because they clog your arteries. Partially hydrogenated vegetable oils (which are artificially saturated fats) are now considered totally evil, both because of the saturation and a side-effect of hydrogenation called trans fatty acids.

Fatty acids that have double bonds come in two forms: trans and cis. "Trans" and "cis" refer to the direction of folding that occurs at the carbon double bonds in unsaturated fatty acids. Cis fatty acids are the normal, natural directions for the folds. A trans fatty acid is chemically identical to the cis form, but folds in an unnatural direction. The trans fatty acids are created by heat (as in deep frying) and by hydrogenation.

It turns out that in the body, the enzymes that deal with fat are unable to deal with the trans fatty acids. Therefore, the enzymes get tied up trying to work on the trans fatty acids, and this can lead to problems with the processing of essential fatty acids.
Clogged Arteries
The heart is an amazing organ. It beats thousands of times each day, every day, for your entire life. In the process, it pumps about five million gallons of blood through your body!

The heart is a muscle, and it needs a supply of oxygen-rich blood to survive. Even though the heart has all of that blood flowing through it while it is pumping, it does not use that blood for its oxygen needs. Instead, there is a set of arteries and veins out on the surface of the heart muscle that feed it. If one of these outer arteries gets blocked, it causes a heart attack. A blockage like this is normally caused by fatty deposits that build up in the heart's arteries over the course of many years. Everything you hear about fat in the diet, cholesterol, coronary artery disease and "clogged arteries" is focused on this problem -- blocked heart arteries and the heart attacks they cause are a leading killer in the United States.



















Essential Fatty Acids
The most common fatty acids are found in animal fats and include:
Palmitic acid
Stearic acid
Oleic acid
Your body is able to create these fats whenever it has a caloric surplus. It can create them from straight sugar if there are enough sugar calories.

It turns out that there is another class of fatty acids called essential fatty acids that your body cannot manufacture. These fatty acids include:
Linoleic acid (LA) (omega-6)
Arachidonic acid (AA) (omega-6)
Gamma linolenic acid (GLA) (omega-6)
Dihomogamma linolenic acid (DGLA) (omega-6)
Alpha linolenic acid (LNA) (omega-3)
Eicosapentaenoic acid (EPA) (omega-3)
Docosahexaenoic acid (DHA) (omega-3)
Because your body cannot manufacture them, they must come in from the food you eat.

Essential fatty acids fall into two groups: omega-3 and omega-6. The 3 and 6 refer to the first carbon double bond position on the fatty acid chain. All essential fatty acids are polyunsaturated, so the 3 and the 6 mean that the first double bond is either 3 or 6 carbons in from the end.

Omega-6 fatty acids are everywhere: corn oil, sunflower oil and soybean oil all contain them. Omega-3 fatty acids are harder to find. Things like flax seeds, pumpkin seeds and walnuts are high in omega-3 fatty acids, as are salmon, trout and tuna. Current thinking is that these two fats need to be balanced in the diet at a ratio like 1-to-1 or 2-to-1, rather than the normal 20-to-1 ratio seen in most Western diets. About the only way to do that is to supplement your diet with omega-3 vegetable oils or to start eating fish in a big way (meaning two or three times a week).

So What Should I Eat?
Summarizing all of this information, the current scientific thinking on fat consumption goes something like this:
Limit your fat intake to about 30 percent of the total calories you consume. Do not try to cut fat intake altogether, because you do need the essential fatty acids. A gram of fat has nine calories, meaning that if you consume 2,000 calories in a day your total fat intake should hover around (2000 * 30 percent / 9 calories/gram) 67 grams of fat.
When consuming fat, try to focus on mono-unsaturated fats like olive oil and canola oil, or on essential fatty acids.
When consuming essential fatty acids, try to balance your intake of omega-6 and omega-3 fatty acids. Do that by consuming tuna/salmon/trout or omega-3 oils like flax seed oil.

Artificial Blood

Doctors and scientists have come up with lots of gadgets that can take over for parts of the body that break or wear out. A heart, for example, is basically a pump; an artificial heart is a mechanical pump that moves blood. Similarly, total knee replacements substitute metal and plastic for bones and cartilage. Prosthetic limbs have become increasingly complex, but they're still essentially mechanical devices that can do the work of arms or legs. All of these are fairly easy to comprehend -- swapping out an organ for a manmade replacement usually makes sense.

Artificial blood, on the other hand, can be mind boggling. One reason is that most people think of blood as more than just connective tissue that carries oxygen and nutrients. Instead, blood represents life. Many cultures and religions place special significance on it, and its importance has even affected the English language. You might refer to your cultural or ancestral traits as being in your blood. Your family members are your blood relatives. If you're outraged, your blood boils. If you're terrified, it runs cold.

Blood carries all these connotations for good reason -- it's absolutely essential to the survival of vertebrate life forms, including people. It carries oxygen from your lungs to all the cells in your body. It also picks up the carbon dioxide you don't need and returns it to your lungs so you can exhale it. Blood delivers nutrients from your digestive system and hormones from your endocrine system to the parts of your body that need them. It passes through the kidneys and liver, which remove or break down wastes and toxins. Immune cells in your blood help prevent and fight off illnesses and infections. Blood can also form clots, preventing fatal blood loss from minor cuts and scrapes.
It can seem improbable, or even impossible, that an artificial substance could replace something that does all this work and is so central to human life. To understand the process, it helps to know a little about how real blood works. Blood has two main components -- plasma and formed elements. Nearly everything that blood carries, including nutrients, hormones and waste, is dissolved in the plasma, which is mostly water. Formed elements, which are cells and parts of cells, also float in the plasma. Formed elements include white blood cells (WBCs), which are part of the immune system, and platelets, which help form clots. Red blood cells (RBCs) are responsible for one of blood's most important tasks -- carrying oxygen and carbon dioxide.

RBCs are numerous; they make up more than 90 percent of the formed elements in the blood. Virtually everything about them helps them carry oxygen more efficiently. An RBC is shaped like a disc that's concave on both sides, so it has lots of surface area for oxygen absorption and release. Its membrane is very flexible and has no nucleus, so it can fit through tiny capillaries without rupturing. red blood cell's lack of nucleus also gives it more room for hemoglobin (Hb), a complex molecule that carries oxygen. It's made of a protein component called a globin and four pigments called hemes. The hemes use iron to bond to oxygen. Inside each RBC are about 280 million hemoglobin molecules.

If you lose a lot of blood, you lose a lot of your oxygen delivery system. The immune cells, nutrients and proteins that blood carries are important, too, but doctors are generally most concerned with whether your cells are getting enough oxygen.

In an emergency situation, doctors will often give patients volume expanders, like saline, to make up for lost blood volume. This helps restore normal blood pressure and lets the remaining red blood cells continue to carry oxygen. Sometimes, this is enough to keep the body going until it can produce new blood cells and other blood elements. If not, doctors can give patents blood transfusions to replace some of the lost blood. Blood transfusions are also fairly common during some surgical procedures.

This process works pretty well, but there are several challenges that can make it difficult or impossible to get patients the blood they need:
Human blood has to be kept cool, and it has a shelf life of 42 days. This makes it impractical for emergency crews to carry it in ambulances or for medical staff to carry it onto the battlefield. Volume expanders alone may not be enough to keep a badly bleeding patient alive until he reaches the hospital.
Doctors must make sure the blood is the right type -- A, B, AB or O -- before giving it to a patient. If a person receives the wrong type of blood, a deadly reaction can result.
The number of people who need blood is growing faster than the number of people who donate blood.
Viruses like HIV and hepatitis can contaminate the blood supply, although improved testing methods have made contamination less likely in most developed countries.

This is where artificial blood comes in. Artificial blood doesn't do all the work of real blood -- sometimes, it can't even replace lost blood volume. Instead, it carries oxygen in situations where a person's red blood cells can't do it on their own. For this reason, artificial blood is often called an oxygen therapeutic. Unlike real blood, artificial blood can be sterilized to kill bacteria and viruses. Doctors can also give it to patients regardless of blood type. Many current types have a shelf life of more than a year and don't need to be refrigerated, making them ideal for use in emergency and battlefield situations. So even though it doesn't actually replace human blood, artificial blood is still pretty amazing.
Artificial Blood Types

PolyHeme HBOC from Northfield Labs


Until recently, most attempts to create artificial blood failed. In the 19th century, doctors unsuccessfully gave patients animal blood, milk, oils and other liquids intravenously. Even after the discovery of human blood types in 1901, doctors kept looking for blood substitutes. World Wars I and II and the discoveries of hepatitis and the human immunodeficiency virus (HIV) also raised interest in its development.

Pharmaceutical companies developed a few varieties of artificial blood in the 1980s and 1990s, but many abandoned their research after heart attacks, strokes and deaths in human trials. Some early formulas also caused capillaries to collapse and blood pressure to skyrocket. However, additional research has led to several specific blood substitutes in two classes -- hemoglobin-based oxygen carriers (HBOCs) and perflourocarbons (PFCs). Some of these substitutes are nearing the end of their testing phase and may be available to hospitals soon. Others are already in use. For example, an HBOC called Hemopure is currently used in hospitals in South Africa, where the spread of HIV has threatened the blood supply. A PFC-based oxygen carrier called Oxygent is in the late stages of human trials in Europe and North America.

The two types have dramatically different chemical structures, but they both work primarily through passive diffusion. Passive diffusion takes advantage of gasses' tendency to move from areas of greater concentration to areas lesser concentration until it reaches a state of equilibrium. In the human body, oxygen moves from the lungs (high concentration) to the blood (low concentration). Then, once the blood reaches the capillaries, the oxygen moves from the blood (high concentration) to the tissues (low concentration). HBOCs
HBOC vaguely resemble blood. They are very dark red or burgundy and are made from real, sterilized hemoglobin, which can come from a variety of sources:
RBCs from real, expired human blood
RBCs from cow blood
Genetically modified bacteria that can produce hemoglobin
Human placentas

However, doctors can't just simply inject hemoglobin into the human bloodstream. When it's inside blood cells, hemoglobin does a great job of carrying and releasing oxygen. But without the cell's membrane to protect it, hemoglobin breaks down very quickly. Disintegrating hemoglobin can cause serious kidney damage.
For this reason, most HBOCs use modified forms of hemoglobin that are sturdier than the naturally-occurring molecule. Some of the most common techniques are:
Cross-linking portions of the hemoglobin molecule with an oxygen-carrying hemoglobin derivative called diaspirin
Polymerizing hemoglobin by binding multiple molecules to one another
Conjugating hemoglobin by bonding it to a polymer

Scientists have also researched HBOCs wrap hemoglobin in a synthetic membrane made from lipids, cholesterol or fatty acids. One HBOC, called MP4, is made from hemoglobin coated in polyethylene glycol.

HBOCs work much like ordinary RBCs. The molecules of the HBOC float in the blood plasma, picking up oxygen from the lungs and dropping it off in the capillaries. The molecules are much smaller than RBCs, so they can fit into spaces that RBCs cannot, such as into extremely swollen tissue or abnormal blood vessels around cancerous tumors. Most HBOCs stay in a person's blood for about a day -- far less than the 100 days or so that ordinary RBCs circulate.

However, HBOCs also have a few side effects. The modified hemoglobin molecules can fit into very small spaces between cells and bond to nitric oxide, which is important to maintaining blood pressure. This can cause a patient's blood pressure to rise to dangerous levels. HBOCs can also cause abdominal discomfort and cramping that is most likely due to the release of free radicals, harmful molecules that can damage cells. Some HBOCs can cause a temporary, reddish discoloration of the eyes or flushed skin. PFCs
Unlike HBOCs, PFCs are usually white and are entirely synthetic. They're a lot like hydrocarbons -- chemicals made entirely of hydrogen and carbon -- but they contain fluorine instead of carbon.

PFCs are chemically inert, but they are extremely good at carrying dissolved gasses. They can carry between 20 and 30 percent more gas than water or blood plasma, and if more gas is present, they can carry more of it. For this reason, doctors primarily use PFCs in conjunction with supplemental oxygen. However, extra oxygen can cause the release of free radicals in a person's body. Researchers are studying whether PFCs can work without the additional oxygen.

PFCs are oily and slippery, so they have to be emulsified, or suspended in a liquid, to be used in the blood. Usually, PFCs are mixed with other substances frequently used in intravenous drugs, such as lecithin or albumin. These emulsifiers eventually break down as they circulate from the blood. The liver and kidneys remove them from the blood, and the lungs exhale the PFCs the way they would carbon dioxide. Sometimes people experience flu-like symptoms as their bodies digest and exhale the PFCs. PFCs, like HBOCs, are extremely small and can fit into spaces that are inaccessible to RBCs. For this reason, some hospitals have studied whether PFCs can treat traumatic brain injury (TBI) by delivering oxygen through swollen brain tissue.

Pharmaceutical companies are testing PFCs and HBOCs for use in specific medical situations, but they have similar potential uses, including:
Restoring oxygen delivery after loss of blood from trauma, especially in emergency and battlefield situations
Preventing the need for blood transfusions during surgery
Maintaining oxygen flow to cancerous tissue, which may make chemotherapy more effective
Treating anemia, which causes a reduction in red blood cells
Allowing oxygen delivery to swollen tissues or areas of the body affected by sickle-cell anemia
Artificial Blood Controversy

At first glance, artificial blood seems like a good thing. It has a longer shelf life than human blood. Since the manufacturing process can include sterilization, it doesn't carry the risk for disease transmission. Doctors can administer it to patients of any blood type. In addition, many people who cannot accept blood transfusions for religious reasons can accept artificial blood, particularly PFCs, which are not derived from blood.

However, artificial blood has been at the center of several controversies. Doctors abandoned the use of HemAssist, the first HBOC tested on humans in the United States, after patients who received the HBOC died more often than those who received donated blood. Sometimes, pharmaceutical companies have had trouble proving that their oxygen carriers are effective. Part of this is because artificial blood is different from real blood, so it can be difficult to develop accurate methods for comparison. In other cases, such as when artificial blood is used to deliver oxygen through swollen brain tissue, the results can be hard to quantify.
Another source of controversy has involved artificial blood studies. From 2004 to 2006, Northfield Laboratories began testing an HBOC called PolyHeme on trauma patients. The study took place at more than 20 hospitals around the United States. Since many trauma patients are unconscious and can't give consent for medical procedures, the Food and Drug Administration (FDA) approved the test as a no-consent study. In other words, doctors could give patients PolyHeme instead of real blood without asking first.
Artificial Cells

Oxygen therapeutics aren't the only artificial cells to make their way into human bodies. Encapsulated islets -- pancreatic cells encased in a synthetic membrane -- can help treat diabetes. Encapsulated charcoal can remove drugs and poisons from a person's blood.


Northfield Laboratories held meetings to educate people in the communities where the study took place. The company also gave people the opportunity to wear a bracelet informing emergency personnel that they preferred not to participate. However, critics claimed that Northfield Laboratories had not done enough to educate the public and accused the company of violating medical ethics.

Blood substitutes may be used as performance-enhancing drugs, much like human blood can when used in blood doping. An October 2002 article in "Wired" reported that some bicyclists were using Oxyglobin, a veterinary HBOC, to increase the amount of oxygen in their blood.

In spite of the controversy, artificial blood may be in widespread use within the next several years. The next generations of blood substitutes will also probably become more sophisticated. In the future, HBOCs and PFCs may look a lot more like red blood cells, and they may carry some of the enzymes and antioxidants that real blood carries.

THE AMAZING WORLD OF PLANTS.

A SHOT AT THE END OF SUMMER: do you enjoy surprises? Try the reaction of Touch-me-not. When ripe, the narrow pods are stretched to breaking point and the slightest touch or shock causes them to explode. The seams of the pods can no withstand the strong tension and burst open. The strong pressure is induced by a quantity of sugar solution in the cells of the issue. When ripe the pods are enormous pressure.
When is a Flower Not a Flower ?
The golden disc looks like a splendid flower on top of thickly leaved stem. But it is not. It is great cluster of small florets the sunflower ( Helianthus annuus).
The centre of the tiny, yellow – brown, tube like florets is encircled with yellow, tongue shaped florets. The centre flowers are fertile but the outer florets are infertile.
They are the signals that attract pollinating insects to land.
The tiny florets, grouped together in what seems to be a single flower, ‘co-operate’ in the pollination by insects. The florets bloom gradually from the circumference in towards the centre. The buds of the tubular flowers are open and push out first of all the dark anthers holding the pollen. They attract bees which are usually busily seeking sweet nectar. The bees suck the juice and wipe themselves against the pollen. Further on they find the flowers that bloomed earlier, nearer to the edges. Their stamens have lost their and so they have prepared their styles and stigmas ready to accept the pollen from the young flowers.
The bee that visited the tubular flowers containing nectar and gathered pollen on its body, runs across the capitulum and inadvertently transfers pollen to the prepared stigmas, pollinating the flowers.

The sunflower is such great sun lover that its flowers can be seen turning their faces to the sun as it slowly moves across the sky. It is one the most useful cultivated plants. The plant was grown by the ancient Indian. The Europeans bred this originally ornamental flower to become an immensely productive flower.

Biological Clock.

You must have all experienced that you tend to wake up almost at the same time everyday in the morning and feeling sleepy as the night falls or why do we so often get up before the alarm is due to sound? Because there is a built in clock inside your body, which regulates sleep – wake timings. All organisms possess an innate biological clock (Pittern drigh 1960).
Rhythms of various kinds have been in the biological world for quite sometimes. It was during Great Alexander’s march to India that one of his officers Androsthenes noted a daily leaf movement among the plants of Tamrind. Rhythmic events occur everywhere in the environment; the sun rises and sets forming days and nights. The bird sings mostly in the morning and evenings.
You must have noticed that your pets especially dogs and cats lose more hair during summers, in winters their fur coat gets thicker.
The most outstanding work on biological clocks was done by Erwin Bunning in 1936.Biological clocks are also known as internal clocks or circadian rhythms are probably a biochemical mechanism. These rhythms allow the animals to adopt their behavior in best possible way to the course of day’s changing event.
Where is the master clock located?
Efforts have been made to locate the master clock of animals in the nervous system. In one study, destruction of neurosecretory cells of brain in the region called pars intercerebralis (PIC) abolished the insect’ clock. The many rhythms studied in vertebrates also. Studies of sparrows exhibit the rhythmic activity have revealed that the pineal body. Sparrows that have their pineal body removed and are kept in darkness continue their activity, but no longer n a rhythmic pattern.
But what generates the rhythm is as yet unknown.
Sources: Animal behavior by Mohan Arora. And Reena Mathur.

An Essential Step.

Dear Friends,

A world without any excitement for the life around it becomes dull and mechanical. Our nation faces this dearth of amazement, we all care about getting the required marks to get into any reputed graduating course and feel contended with a 9 to 6 job. But why do not we just look out of our window and watch how the first few drops of rain bring our surrounding envirornment to life, we cease to see what boon our great planet has got. Man is a creator, but that is a misunderstood word when it comes to biological awareness, we are stunned when we come to know how life sustains itself even in the harsh climates of which we even do not dream of, isnt that fascinating enough. Let us go through a journey through this blog and become aware of what mother Earth has endured in her for time immemorial = LIFE.

KARTIK.MULGUND