natural science ppt science and islam....

science with islam

1. Lecture 4 & 5 - Carbohydrates For BS. Islamiat Studies (SEM-I)

2. Learning Outcomes Types, Role in body, Dietary fiber, bulk and alternative sweeteners, Recommended intake and energy value

3. What are Carbohydrates? Carbohydrates contain carbon, hydrogen and oxygen. They are widely distributed in plants in which they are formed from carbon dioxide of the atmosphere and water from the soil through photosynthesis. The nutritionally important major groups of carbohydrates are: Sugars (monosaccharides and disaccharides) O ligosaccharides P olysaccharides (starch, cellulose, pectic substances and related compounds). Carbohydrates constitute by far the greatest portion of diet in developing countries, as much as 80% in some cases. In industrialized countries 45 to 50% carbohydrates are included in the diet of a person.

4. Types of Carbohydrates 1. Sugars/Simple Carbohydrates: Sugars are white, crystalline, water soluble and varyingly sweet in taste. They are modified by heating/cooking, i.e., caramelise on heating. They act as preservatives in jams, jellies, marmalades and preserves owing to their water binding capability. When oxidised in the human body, they provide energy (3.75 kcal/g or 16 kJ) which is essential for all body activities. Sugars are building blocks of such complex carbohydrates as starches, celluloses, pectins and glycogen (polysaccharides).

5. How Sugar is Harmful? Sugars naturally present in the cellular structure of fruits, some vegetables, are intrinsic and pose no threat to health. Those extracted, refined, and concentrated (household sugar) are extrinsic sugars. These can contribute to dental caries, obesity and other ailments.

6. Types of Sugars

7. Monosaccharides Monosaccharides contain just one sugar unit, so they’re the smallest of the carbohydrates. (The prefix “mono-” means “one.”) The small size of monosaccharides gives them a special role in digestion and metabolism. Food carbohydrates have to be broken down to monosaccharides before they can be absorbed in the gastrointestinal tract, and they also circulate in blood in monosaccharide form. There are 3 monosaccharides: Glucose Fructose Galactose

8. Glucose You’re already familiar with glucose, because it’s the main product of photosynthesis. Plants make glucose as a way of storing the sun’s energy in a form that it can use for growth and reproduction. In humans,  glucose is one of the most important nutrients for fueling the body. It’s especially important for the brain and nervous system, which aren’t very good at using other fuel sources.   Muscles , on the other hand, can use fat as an energy source. Food sources of glucose:  Glucose is found in fruits and vegetables, as well as honey, corn syrup, and high fructose corn syrup. (All plants make glucose, but much of the glucose is used to make starch, fiber, and other nutrients. The foods listed here have glucose in its monosaccharide form.)

9. Fructose Fructose is special because it is the sweetest carbohydrate.  Plants make a lot of fructose as a way of attracting insects and animals, which help plants to reproduce.   For example, plants make nectar, which is high in fructose and very sweet, to attract insects that will pollinate it. Plants also put fructose into fruit to make it tastier. Animals eat the fruit, wander away, and later poop out the seeds from the fruit, thereby sowing the seeds of the next generation. Animal gets a meal, and the plant gets to reproduce: win-win!

10. Galactose Food sources of galactose: Galactose is found in milk (and dairy products made from milk), but it’s almost always linked to glucose to form a disaccharide (more on that in a minute). We rarely find it in our food supply in monosaccharide form.

11. Disaccharides The second type of simple carbohydrates is disaccharides. They contain two sugar units bonded together. There are 3 disaccharides: Maltose (glucose + glucose) Sucrose (glucose + fructose) Lactose (glucose + galactose)

12. Oligosaccharides Oligosaccharides are glycosides, water-soluble polymers of a few (3 to 10 carbon atoms) condensed monosaccharides. Those most commonly found in foods are generally homopolymers of D-glucose ( malto -oligosaccharides ) or heteropolymers of D-glucose condensed with D. fructose or D-galactose ( raffinose , stachyose , fructo oligosaccharides). The oligosaccharides occur as F ructo -oligosaccharides (in onions and garlic ), Galacto -oligosaccharides-+ or soybean oligosaccharides in the form of raffinose and stachyose in soybean. Xylo -oligosaccharides , composed of xylobiose and xylotriose are found in fruits, honey and milk.

13. Oligosaccharides The physiologically functional oligosaccharides are short-chain polysaccharides that meet two specific requirements: a. They are not digested by human gastric juice. b. They are preferentially consumed by beneficial intestinal bacteria, the Bifidobacteria , in the colon . Bifidobacteria produce some short chain fatty acids, mainly acetic and lactic acids and some antibiotic material. These bacteria possess antagonistic effect . They suppress the activity of putrefactive and pathogenic bacteria and reduce formation of toxic fermentation. In addition, Bifidobacteria produce some vitamins of the B group.

14. Oligosaccharides Oligosaccharides have become popular functional food components in Japan and some other developed countries. These are consumed as such or as food ingredients. Most common products are beverages, infant milk formulations, confectionery, bakery products, yoghurts and dairy desserts. Two to three grams oligosaccharides per day are recommended in the diet of adults to provide following beneficial effects: - a . Help in the proliferation of Bifidobacteria that reduce the numbers of detrimental bacteria including pathogenic organisms. b . Reduce toxic metabolites and deleterious enzymes and increase the production of useful nutrients. c . Prevent constipation and protect liver functions. d . Reduce serum cholesterol level and blood pressure. e . Have an anticancer effect.

15. Complex Carbohydrates Complex carbohydrates are also called polysaccharides, because they contain many sugars. (The prefix “poly-” means “many.”) There are 3 main polysaccharides: Starch Glycogen Fiber All three of these polysaccharides are made up of many glucose molecules bonded together, but they differ in their structure and the type of bonds.

16. Complex Carbohydrates Starch is the storage form of carbohydrate in plants. Plants make starch in order to store glucose.  Glycogen   is the storage form of carbohydrate in animals , humans included. It’s made up of highly branched chains of glucose, and it’s stored in the liver and skeletal muscle . Fiber includes carbohydrates and other structural substances in plants that are indigestible to human enzymes. Fiber is made by plants to provide protection and structural support. Think about thick stems that help a plant stand upright, tough seed husks, and fruit skin that protect what’s growing inside. These are full of fiber.

17. Energy Energy is obtained by the oxidation of carbohydrates, oils, fats and proteins contained in the diet as well as from chemical reactions in the body. Many people consider energy as good and calories as bad or fattening. Both are actually the same. Calorie (Cal) or kilocalorie (kcal) is the unit of measurement of energy. Joule (J) or kiloJoule (kJ) is the equivalent international (S.I.) unit. Calorie (Cal or kcal) is defined as the amount of heat required to raise the temperature of one kilogram of water by 1°C.

18. Energy About half of the daily intake of energy is obtained from controlled oxidation of carbohydrates, fats and proteins in the diet. It is used for self-maintenance, including: - a. Liberation of energy from glucose and fatty acids reactions. b. Synthesis of new proteins for growth and repair. c. Elimination of wastes from blood by kidney. d. Maintenance of body temperature at 37°C. e. Maintenance of electrolyte concentration in the cells. f. Contraction of muscles in breathing. g. Contraction of heart muscles.