everyday sci

8/8/2019 Everyday Sci

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ASSIGMENT ON

PRESENTED BY

ANUM AHMADROLL NO.11

PRESENTED TO

SIR SHAHZAD SALEEM

DATED: 26th JAN, 2009

DEPARTMENT OF PUBLIC ADMINISTRATION

UNIVERSITY OF KARACHI



The term carbohydrate is actually a descriptor of what these molecules are composed of.

They are “carbon hydrates,” in a ratio of one carbon molecule to one water molecule

(CH2O)n.

You may recognize carbohydrates as source of energy (starch, glycogen), but they fulfill

a wide range of roles, including the structural materials of plants (cellulose in plant cellwalls) and of some animals chitin of an insect’s exoskeleton.

Carbohydrates can also be components of other molecules such as DNA, RNA,

glycolipids, glycoprotein, and adenosine triphosphate (ATP). Carbohydrates, pronounced(car-bo-hi-drayts) are sugars that provide the body with energy. Your body can break

carbohydrates down quickly and efficiently.

Carbohydrates are an ideal source of energy for the body. This is because they can be

converted more readily into glucose, the form of sugar that's transported and used by the

body, than can proteins or fats.

Even so, a diet too high in carbohydrates can upset the delicate balance of your body's

blood sugar level, resulting in fluctuations in energy and mood that leave you feeling

irritated and tired.

Carbohydrate rich foods in their natural state are low in calories and high in fiber.

Carbohydrates contain about 4 calories per gram. Fat contains about 9 calories per gram.



KINDS OF CARBOHYDERTES:

There are two types of carbohydrate: complex and simple.

1. COMPLEX CARBOHYDERATE:

Complex carbohydrates are often referred to as starch or starchy foods. They are

found naturally in foods and also refined in processed foods. Complex carbohydratesinclude fiber and starches. They can be found in vegetables, bread, rice, oatmeal,

whole grains, peas and beans. Complex carbohydrates take longer to be digested, so

your body needs more time to release these carbs into your blood as glucose

Complex carbohydrates as natural starches are found in:

• bananas

• barley

• beans

• brown rice

• chickpeas

• lentils

• nuts

• oats

• parsnips• potatoes

• root vegetables

• sweet corn

• wholegrain cereals

• whole meal breads

• whole meal cereals

• whole meal flour

• whole meal pasta



Complex carbohydrates as refined starches are found in:

• biscuits, pastries and cakes

• pizzas

• sugary processed breakfast cereals

• white bread

• white flour

• white pasta

• white rice.

2. SIMPLE CARBOHYDERATE:

Simple carbohydrates are also known as sugars. They also exist in either a natural or

refined form. Simple carbohydrates are also called simple sugars. Simple carbohydrates

include: fructose (fruit sugar), sucrose (table sugar) and lactose (milk sugar), as well asseveral other sugars. Simple carbohydrates are great sources of quick energy.

Natural sugars are found in fruit and vegetables. Simple carbohydrates (sugar) cause

tooth decay.

Refined sugars are found in:

• biscuits, cakes and pastries

• chocolate

• honey and jams

• jellies

• brown and white cane sugar

• pizzas

• prepared foods and sauces

• soft drinks

• sweets and snack bars.



THE DIFFERENCE BETWEEN SIMPLE AND COMPLEX

CARBOHYDERATE:

All carbohydrates form glucose when digested. Glucose is transported around the body

via blood and taken into cells to be converted into energy.

The pancreas gland in your abdomen secretes the hormone insulin which controls the

uptake of glucose by your cells.

If you have any excess glucose, this is converted into glycogen which is stored in the

liver or in fat around the body.

When your body needs more energy, a second hormone called glucagons is secreted by

the pancreas. This converts the glycogen back into glucose, which is then released intoyour bloodstream for your cells to use.

This means the body's glucose (sugar) metabolism is a cycle of glucose, insulin and

glucagons reactions.

The slower the release of glucose and hormones, the more stable and sustainable the

energy levels of the body.

The more refined the carbohydrate, the faster the glucose is released into your blood. Thiscan cause peaks and drops in your blood sugar level, and less stable energy levels in the

body.

Complex carbohydrates provide a slower and more sustained release of energy than

simple carbohydrates.

In their natural form they contribute to long-term good health, appetite control and

sustained energy levels.



CATEGORIES OF CARBOHYDERATE:

There are three categories in which the carbohyderates are divided to clarify the structure

of different types of carbohyderate.

1. GLUCOSE:

Carbohydrates have been given non-systematic names, although the suffix ose is

generally used. The most common carbohydrate is glucose (C6H12O6). Applying the terms

defined above, glucose is a monosaccharide, an aldohexose (note that the function andsize classifications are combined in one word) and a reducing sugar. The general

structure of glucose and many other aldohexoses was established by simple chemical

reactions. The following diagram illustrates the kind of evidence considered, although

some of the reagents shown here are different from those used by the original scientists.

2. KETOSES:

If a monosaccharide has a carbonyl function on one of the inner atoms of the carbonchain it is classified as a ketose. Dihydroxyacetone may not be a sugar, but it is included

as the ketose analog of glyceraldehyde. The carbonyl group is commonly found at C-2, as

illustrated by the following examples (chiral centers are colored red).

http://chng1%28%29/



Although the ketoses are distinct isomers of the aldose monosaccharides, the chemistry of

both classes is linked due to their facile interconversion in the presence of acid or basecatalysts.

3. GLYCOSIDES:

Acetyl derivatives formed when a monosaccharide reacts with an alcohol in the presence

of an acid catalyst are called glycosides.

In naming of glycosides, the "ose" suffix of the sugar name is replaced by "oside", andthe alcohol group name is placed first. As is generally true for most aldols, glycoside

formation involves the loss of an equivalent of water.

http://chng3%28%29/



Glycosides abound in biological systems. By attaching a sugar moiety to a lipid or

benzenoid structure, the solubility and other properties of the compound may be changedsubstantially. Because of the important modifying influence of such derivatization,

numerous enzyme systems, known as glycosidase, have evolved for the attachment and

removal of sugars from alcohols, phenols and amines. Chemists refer to the sugar component of natural glycosides as the glycon and the alcohol component as the aglycon.

TYPES OF CARBOHYDERATE:

The three main types of carbohydrate are:

• Starch (also known as complex carbohydrates)

• Sugar

• Fiber

STARCH:

The grain group can be broken down even further into whole grain or refined grain.A

grain, let's take wheat for example, contains three parts. The parts are the bran, germ, andthe endosperm.

Foods high in starch include:

• Starchy vegetables like peas, corn, lima beans, and potatoes

• Dried beans, lentils, and peas such as pinto beans, kidney beans, black eyed peas,

and split peas

• Grains like oats, barley, and rice.



SUGAR:

Sugar is another type of carbohydrate. There are two main types of sugar naturally

occurring sugars such as those in milk or fruit

There are many different names for sugar. Examples of common names are table sugar, brown sugar, molasses, honey, beet sugar, cane sugar, confectioner's sugar, powdered

sugar.

Table sugar listed by its chemical name, sucrose. Fruit sugar is also known as fructose

and the sugar in milk is called lactose. You can recognize other sugars on labels becausetheir chemical names also end in "-ose." For example glucose (also called dextrose),

fructose (also called levulose), lactose, and maltose.

FIBER:

Fiber comes from plant foods so there is no fiber in animal products such as milk, eggs,meat, poultry, and fish. Fiber is the indigestible part of plant foods, including fruits,

vegetables, whole grains, nuts, and legumes.

Because fiber is not digested like other carbohydrates, for carbohydrate counting

purposes, if a serving of a food contains more than or equal to 5 grams of dietary fiber,

SACCHARIDES:

The word saccharide is a synonym for carbohydrate and is generally preceded with a

prefix indicating the size of the molecule (mono-, di-, tri- poly-).

http://www.diabetes.org/food-nutrition-lifestyle/nutrition/meal-planning/sweeteners-desserts.jsp

http://www.diabetes.org/food-nutrition-lifestyle/nutrition/meal-planning/sweeteners-desserts.jsp



1. MONOSACCHARIDE: Monosaccharides (from Greek monos: single, sacchar : sugar) are the most basic unit of

carbohydrates. They consist of one sugar and are usually colorless, water-soluble,

crystalline solids. Some monosaccharides have a sweet taste. Examples of monosaccharides include glucose (dextrose), fructose, galactose, xylose and ribose.

• single sugars (one molecule)

• simplest examples are glucose and fructose

Glucopyranose (monosaccharide)

2. DISACCHARIDE: Disaccharide is a sugar (a carbohydrate) composed of two monosaccharides.

'Disaccharide' is one of the four chemical groupings of carbohydrates (monosaccharide,

disaccharide, oligosaccharide, and polysaccharides.

• double sugars

• combination of two monosaccharides

• sucrose = glucose + fructose

• lactose = glucose + galactose

3. POLYSACCHARIDE:



The term polysaccharide is limited to those polymers which contain 10 or more

monosaccharide residues. Polysaccharides such as starch, glycogen, and dextran consist

of several thousand D-glucose units. Polymers of relatively low molecular weight,

consisting of two to nine monosaccharide residues, are referred to as oligosaccharides.

A polysaccharide consisting of hexose monosaccharide units may be represented by the

reaction below.

• polymers composed of several sugars

• can be same monomer (many of same monosaccharide) or mixture of monomers

• glycogen is the major stored carbohydrate in animals

• Starch is storage polysaccharide of plants. It is a long chain of glucose molecules.

• chitin is a structural carb in some animals

• cellulose is the major structural carbohydrate in plants

FUNCTIONS OF CARBOHYDRATE:

Under are given the major functions of carbohydrate



• When your body needs energy, it looks for carbohydrates first.

• If you are not consuming enough carbohydrates, your body will look for other sources of energy, such as proteins found in muscle tissue. Proteins, however, are

not efficient sources of energy for the body.

• Carbohydrates are most abundant dietary source of energy for all organisms.• They supply energy and serve as storage form of energy.

• Carbohydrates such as glucose, fructose, starch, glycogen, etc. provide energy for

functioning of living organisms.

• Carbohydrates also protect your muscles and help regulate the amount of sugar

circulating in your blood so that all the cells get the energy they need.

• Carbohydrates participate in cellular functions such as cell growth, adhesion andfertilization.

MYTH ABOUT CARBOHYDERATE INTAKE:

Carbohydrates (sugar, starch and fiber) are made in plants from carbon, hydrogen and

oxygen. When you eat plants, or foods made from them, your body gets the energy itneeds for fuel (calories). Many people believe that eating carbohydrates will make you

fat. That's not true. In fact, there are only four calories in a gram of carbs. Compared to

the other energy-yielding nutrients, fat and protein, carbohydrates have less than one half of the calories in fat and the same number of calories as protein. Excess calories, or more

than your body needs, from any of these three energy sources — carbohydrate, fat or

protein — will put on weight.

It may surprise you to learn that many studies in the United States and other countries

show that people who eat more sugar and other carbohydrates tend to weigh less than

those who eat smaller amounts. Carbohydrates are a less efficient fuel than fat.Converting the carbohydrates you eat into stored body fat uses up 25 percent of the

calories. Converting the fat you eat into stored body fat uses up only 3 percent of the fat

calories. It is better to balance your intake of carbohydrates with protein, a little fat andfiber.

WHY HUMAN NEEDS CARBOHYDERATE:



Carbohydrates (sugar, starch and fiber) are made in plants from carbon, hydrogen and

oxygen. When you eat plants, or foods made from them, your body gets the energy it

needs for fuel (calories). Many people believe that eating carbohydrates will make you

fat. That's not true. In fact, there are only four calories in a gram of carbs. Compared to

the other energy-yielding nutrients, fat and protein, carbohydrates have less than one half of the calories in fat and the same number of calories as protein. Excess calories, or more

than your body needs, from any of these three energy sources — carbohydrate, fat or

protein — will put on weight. It may surprise you to learn that many studies in the United

States and other countries show that people who eat more sugar and other carbohydrates

tend to weigh less than those who eat smaller amounts. Carbohydrates are a less efficient

fuel than fat. Converting the carbohydrates you eat into stored body fat uses up 25

percent of the calories. Converting the fat you eat into stored body fat uses up only 3

percent of the fat calories.

HOW MUCH CARBOHYDERATE SHOULD ONE GET DAILY?

You need at least 100 grams of carbohydrate a day to meet the needs of your brain and

other body tissues that do not easily use other fuels. Adequate carbohydrate will also

reduce the amount of body protein that is broken down. Some carbohydrates are needed

to help break down body fat and prevent the accumulation of ketones (formed when fat is

broken down), which can upset the normal balance in the body.

Experts recommend that we get about 60 percent of our calories from carbohydrates. The

Daily Values (DV), printed on food labels, suggest 300 grams of carbohydrate (1200

calories) in a 2,000-calorie diet, which is 60 percent of daily calories. Calorie intake each

day varies depending on your body size and level of activity.

WHY DO PEOPLE COUNT CARBOHYDERATES?



Many people count carbohydrates. You can do so to keep track of your carbohydrate and

sugar intake in order to lose weight, if you are an athlete or if you have diabetes.

The Carbohydrate, Fiber, and Sugar Counter will help you count carbohydrates by telling

you how many grams of carbohydrate and sugar are in the foods you eat. Reasonable

amounts of sugar and sugar-containing foods, such as cookies, can be included. Just be

careful that sugary foods do not crowd out more healthy carbohydrate choices.

SOME FACTS ABOUT EFFECTS OF CARBOHYDERATE IN

DEVELOPED COUNTRIES:

1. The average American eats 142 pounds of sugar and corn syrup a year, along with

24 pounds of low-calorie sweeteners.

2. The average American gets 16 percent of his or her calories from added sugars.

Teens get 20 percent, mainly from sodas, cookies, cakes, and pastries. Teenage

boys, on average, drink more than 575 cans of soda a year, while teenage girls

drink more than 400 cans.

3. Americans are eating more cereal — 60 percent more than in the late 1970s.

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