Carbohydrates are the main source of energy and are made up of carbon, hydrogen, and oxygen. They are classified as monosaccharides, disaccharides, oligosaccharides, or polysaccharides depending on the number of sugar units. The three main monosaccharides are glucose, fructose, and galactose. Carbohydrates provide 4 calories per gram and are important for energy, sparing protein use, and regulating blood glucose. Deficiencies can cause malnutrition like marasmus while overconsumption can lead to obesity.

1. Carbohydrates
BY MONIKA PAL
NURSING TUTOR

2. INTRODUCTION
 Carbohydrates is the main source of energy and form the bulk of our
diet.they are availablein the market in the natural form,processedform or
modified form as an additive in many different products.carbohydrates
are widely, distribute in plants in Which they are formed by the action of
photosynthesis.

3. DEFINITION
 Carbohydrates are organic compounds made up of carbon, hydrogen,
oxygen.they are calledcarbohydrates because they contain hydrogen
and oxygen in same proportion as found in water.
 C6h12o6(glucose)
 C12h22o11(table sugar).

4. CLASSIFICATION OF CARBOHYDRATES
 1.monosaccharides (made up of 2-6 carbon units)
 2.disaccharides(made up of 2monosaccharides)
 3.oligosaccharides(made up of 3-10monosaccharides)
 4.polysaccharides(made up of 10or more monosaccharides)

5. MONOSACCHARIDES
 1.Monosaccharides=(containa singleunit)
 These are the simplest forms of carbohydrates found in nature. Three
monosaccharides are of important in human nutrition.they are glucose,
fructose,andgalactose.
 ✓glucose – it is the primary carbohydrates used by the body glucose is the
sugar.which is absorbed into the bloodstream after carbohydrates are
digested in the body it is also known as dextrose and availablein powder
and liquidform.

6.  ✓fructose= it is the sweetest of all sugar and is also known as fruit sugar
because it is found in fruits and honey in human body it is convertedto
glucose and oxidisedas a source of energy it is also calledlevulose.
 ✓galactose= it is found in combination with glucosein milk this sugar is
convertedto glucose in human body.

7. DISACCHARIDES
 2.disaccharides=(contain two’sugar unit)
 These are double sugars composedof two monosaccharides linked
together with the removal of water molecule.
 The disaccharides which are of important in the diet are sucrose,maltose
and lactose.their general formulais c12h22o11.

8. OLIGOSACCHARIDES AND
POLYSACCHARIDE
 3.oligosaccharides=they are composedof three to ten monosaccharides
unit’s linkedto each other by the removal of water molecules.
 They are formedduring break down of starch into simpler sugars
eg,raffinose and stachyose.theyare not as common in good as the
mono,di and polysaccharid
 4.polysaccharides=(most contain glucose as the monosaccharides unit’s)
 These are complex carbohydrates made up of 100to2000 glucose unit’s
linkedto each other in a chain or branched form..

9.  • starches- they form approximately half the diatray carbohydrates which
are consumed.they are present in abundance in cereals,pulses, Tapioca,
root’s.
 •glycogen- this also calledanimal starch as it is the form in which the
animal source of energy approximately 400to500gm of glycogen is stored
in the body.
 •Dextrin
 •Dietary fibers

10. CALORIE VALUE
 Calorie value= 1gm of carbohydrates yields 4calories of energy.
 RECOMMENDED DAILY ALLOWANCES
 At Least 313gm of carbohydrates per day shouldbe consumed,ifdaily
calorie requirements is 2,500 calories.
 At least 250gm of carbohydrates per day should be consumed,if daily
calorie requirements is 2,000 calories.
 At least 188gm of carbohydrates per day should be consumed,if daily
calorie requirements is 1,500 calories.

11.  Most people shouldget between 40%and60% of total calories from
carbohydrates, preferably from complex carbohydrates (starches) and
natural sugars.complexcarbohydrates provide calories, vitamins,
minerals,andfiber.
 Food that are High in processed, refined simplesugars provide calories,but
very little nutrition.it is wise to limit these sugars.
 To increase complexcarbohydrates and healthy nutrients.

12. Dietary sources
 1)Dairy- milk, yogurt, ice-cream.
 2)Fruit- whole fruit and fruit juice.
 3) Grains- bread, rice, crackers, and cereal
 4) Legumes- beans and other plant based proteins.
 5)Starchy vegetables- potatoes and corn.

13. Functions
 Carbohydrates have six major functions with in the body.
 • providing energy and regulations of blood glucose.
 • sparing the use of proteins for energy.
 • preventing breakdown of fatty acids and ketosis.
 • biological recognition processes.
 • Flavor and sweeteners.
 •dietary fiber.

14. Digestion, Absorption and storage.
 Digestion
 Carbohydrates are formed in growingplants and are found in grains,leafy
vegetables and other edible plants food. The digestive system starts the
process of breakingdown polysaccharide in the mouth through the
introduction of amylase,a digestive enzyme in Saliva.
 The High acid content of the stomach inhibits the enzyme activity,so
carbohydrates digestion is suspended in the stomach.
 Simple sugars are the predominant carbohydrates absorbed in the digestive
tract, and in many animals the,most important source of
energy.monosaccharides, however,are only rarely found in Normal
diets.rather,they are derived by enzymatic digestion of more complex
carbohydrates with in the digestive tube

15. Absorption
 Absorption of glucose entails transport from the intestinal lumen, across the
epithelium and into blood.
 1. The transporter is initially oriented facing into the lumen at this point it is
capable of binding sodium,but not glucose.
 2. Sodium binds, inducing a conformational changes that opens the
glucose-binding pocket.
 3. Glucosebinds and the transporter reorient in the membrane such that
the pocket holding sodium and glucose are movedinside the cell.
 4. Sodium dissociates into the cytoplasm, causing glucose binding to
destabilize.

16.  5. Glucosedissociates into the cytoplasm and the unloaded transporter
reorient back to it’s original, outward facing position.

17. Storage
 There are only 1200 calories stored as carbohydrates in liver and muscle
glycogen. There are clear adaptive advantages to storing calories as
fat,Since fat can provide more energy Per gram than carbohydrates or
protein.
 COVERSION OF CARBOHYDRATES INTO FAT.
 Conversionof carbohydrates into fat allows animals to buildup fat reserves
even when their feed contains very little fat.
 In adult human such de Novo lipogenesis is primarily a hepatic process.

18. Metabolism of carbohydrates
 Glucose,galactose and fructose are absorbed in the intestineand pass to
the liver through portal circulation.in the liver,apart of glucose and the
entire galactose and fructose are convertedinto glycogen.
 A part of glucose passes into the general circulation, to the various tissues
for being oxidized and used as energy.
 A small part of glucose is stored in the liver and muscles as glycogen and
some portion of glucose is convertedinto fat and stored in adipose tissue.
 The oxidation of glucose in the tissue occurs in two stages called'glycolysis’
and tricarboxylic acid cycle.
 Glycogen = Glucose = Pyruvicacid = Lactic acid

19.  In this stage glucose is oxidizedto form Pyruvic acid.the oxidation of
Pyruvicacid takes place through a series of reaction or various metabolic
cycles;energy is releasedin the form of adenosine triphosphate (ATP).
 Pyruvicacid = Oxidation = Carbon dioxide + water
 The waste products of carbohydrates metabolism are carbon dioxide and
water, excreted by the body.

20. Malnutrition deficiencies and over
consumption
 MALNUTRITION
 Not getting enough carbohydrates can cause a lack of calories
(malnutrition), or getting too many carbohydrates can lead to an increase
in total calories, causing obesity.
 DEFICIENCIES
 Marasmus – marasmus is the most common form of proteins energy
malnutrition(PEM) you will observe among children below 1year of
age.marasmus is caused when the mother suddenly stops breast feeding
the childand instead feeds him on Starchy food’s like sago, potato,etc
 This results in providing insufficient energy and protein to the childleading
to marasmus.lack of these important nutrients, results in marasmus.

21. Clinical features of marasmus child
 • Muscle wasting: due to the inadequacy of energy and protein in the
diet, the muscles get loose and skin becomes wrinkled. The childlooks
very'thin and week’.
 • Irritability: the child become extremely weak and becomes irritable.the
childcries continuously.his cries can be barely heard due to extreme
weakness.
 • Growth failure: deficiency of energy and protein can not meet the
increase requirements of the growing body the child.hence the childfails
to grow and thus is smaller than the healthy children of his age.

22.  •Diarrhea : A marasmicchildhas frequent watery stools (diarrhoea).
Consequently,the childgets dehydrated.

23. Kwashiorkor
 KWASHIORKOR = is mainly caused by inadequate protein intake the main
symptoms are edema wasting, liver enlargement

24. Over consumption
 Obesity is an excess proportion of total body fat. A person is considered
obese when his or her weight is 20% or more above normal weight. The
most common measure of obesity is the body mass index.