SCIENCE PROJECTTITLE: CHAPTER 2 NUTRITIONNAME : OW SEAN RHEI(2 BIJAK)WONG ZI WEI (2 ARIF )LIEW KIT YEE (2DEDIKASI)WONG YOK...
CarbohydratesFoods rich in carbohydratesCarbohydrates are organic compounds made up of the elements carbon, hydrogen and o...
FatsFoods rich in fatsFats are compounds of carbon, hydrogen and oxygen. Fat is stored under the skin or around organs ino...
Vitamin    Source                          Function                                  Deficiency diseaseA          Carrot, ...
Mineral      Source                      Function                       Deficiency diseaseCalcium      Cheese, milk, eggs,...
also need food to grow. Food can be divided into seven classes .Classes Of Food - Carbohydrates               - Proteins  ...
FibreFoods rich in FibreFibre is also known as roughage. Fibre is made up of cellulose from plant cell walls. Fruits, vege...
2.2 The Importance of a Balanced DietDiet refers to all the food we eat each day. We need to have a balanceddiet in order ...
Athletes in serious raining require energy intakes similar to that of manualworkers.    People who do not eat a balanced d...
Egg              1 egg              315   Fried kuih teow   1 plate   1 348Kuih koci        1 piece            344   Egg b...
2.3 Human Digestive SystemThe food we eat consists of a minute of carbohydrates, proteins and fats which must bebroken dow...
Human Digestive SystemMouth~Food is chewed into smaller pieces and mixed with saliva secreted by the salivary glands.
~Salivary amylase catalyses the breaking down of starch into maltose.Stomach~Stomach wall produces gastric juices which co...
The villi greatly increase the surface area of the small intestine so that absorption of digested food can take placequick...
canal- the large intestine. The residue remains in the large intestine for 12 to 24 hours.At the residue passes through th...
much salt can cause high blood pressure, a major factor in stroke. Excessive fats can cause high blood cholesterollevels w...
2.1 Classes of food……………………..………….. 1    *Carbohydrates……….. …………............................................. 2*Proteins…...
Upcoming SlideShare
Loading in …5
×

SMK DATOK LOKMAN SCIENCE PROJECT

590 views

Published on

0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
590
On SlideShare
0
From Embeds
0
Number of Embeds
1
Actions
Shares
0
Downloads
0
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

SMK DATOK LOKMAN SCIENCE PROJECT

  1. 1. SCIENCE PROJECTTITLE: CHAPTER 2 NUTRITIONNAME : OW SEAN RHEI(2 BIJAK)WONG ZI WEI (2 ARIF )LIEW KIT YEE (2DEDIKASI)WONG YOKE KEI (2 GIGIH )TEACHER:Cikgu Farihah binti Muhd JamelSCHOOL : S.M.K DATOK LOKMAN
  2. 2. CarbohydratesFoods rich in carbohydratesCarbohydrates are organic compounds made up of the elements carbon, hydrogen and oxygen.Carbohydrates supply most of the energy our body needs. Carbohydrates include sugars, starches and cellulose. Sugars are sweet and dissolve readily in water.An example of sugar is glucose. Sugars are found in honey, sugar cane and fruits. Starch is found in foodsuch as rice, bread and potatoes. Glycogen or ‘animal starch’ is stored in our liver and muscles. Celluloseoccurs in plant cell walls. Starch, glycogen and cellulose are made up of many glucose molecules joinedtogether.ProteinsFoods rich in proteinsProteins are organic compounds containing carbon, hydrogen, oxygen and nitrogen. Sometimes sulphurand phosphorus are also present. A molecule of protein is made up a large number of subunits calledamino acids can be made by our body cells while others must be supplied through the food that we eat. Proteins are needed for growth and the repair of body tissues. Proteins are required for theformation of enzymes, hormones, hemoglobinand antibodies in our body.
  3. 3. FatsFoods rich in fatsFats are compounds of carbon, hydrogen and oxygen. Fat is stored under the skin or around organs inour body. Fat helps to keep us warm and protects organs from damage. Fat help to transport vitamins A,D, E and K. Fat can store a lot of energy.VitaminsFoods rich in vitaminsVitamins are organic compounds needed in small amounts by our body for health and growth. Vitaminsare divided into two groups: the water-soluble vitamins and the fat-soluble vitamins. The water-solublevitamins are vitamin B and vitamins C. The fat-soluble vitamins are vitamins A, vitamins D, vitamins Eand vitamins K. Table 2.1 list some major vitaminsTable 2.1 Vitamins
  4. 4. Vitamin Source Function Deficiency diseaseA Carrot, liver fish oil and For night vision Night blindness green vegetables Healthy skin Skin infectionsB Eggs, milk, meat, yeast and Releases energy from Beriberi cereals carbohydrates Anemia Healthy nervous system Healthy skin Formation of red blood cellsC Fresh fruits and vegetables Healing of wounds Scurvy (bleeding Resistance to diseases gums)D Made by our body in Strong bones and teeth Rickets (soft bones sunlight, also found in milk, and dental decay) eggs, fish liver oilE Vegetable oil, whole grains, May be needed for reproduction Sterility nuts, wheat germ Helps to fight against diseasesK Made in the human Clotting of blood Prolonged bleeding intestines, also found in egg yolk, green vegetablesMineralsFoods rich in mineralsMinerals are inorganic substances needed by our body in small amounts for healthy growth anddevelopment. Table 2.2 shows some of the minerals needed by our body. Like vitamins, lack of mineralscan cause diseases too.Table 2.2 Minerals
  5. 5. Mineral Source Function Deficiency diseaseCalcium Cheese, milk, eggs, green  Strong bones and teeth  Rickets vegetables  Blood clotting  Osteoporosis  Muscle and nerve  Prolonged bleeding activities  Muscular crampsSodium Table salt, cheese, meat  Maintains body fluid  Muscular cramps  Proper functioning of nervesIron Meat, eggs, green  Needed to form  Anemia vegetables hemoglobin in red blood cellsIodine Seafood, iodized salt  Needed to make  Goiter (swelling of hormones of the thyroid the thyroid gland gland in the neck)Phosphorus Eggs, meat, milk, cheese,  Strong bones and teeth  Rickets vegetables  Muscle contraction  Weakness  Stores energyPotassium Meats, nuts, bananas  Maintains body fluids  Weak muscles  Proper functioning of  Paralysis nerves  Regulation of heartbeat2.1 Classes ofFoodOur body depend on food for energy to do work and stay health. We
  6. 6. also need food to grow. Food can be divided into seven classes .Classes Of Food - Carbohydrates - Proteins - Fats - Vitamins - Minerals - Fibre - WaterCarbohydrate,proteins,fats,vitamins, and minerals are also called nutrientsbecause they contain useful substances required by our body. The process ofobtaining and using nutrients from food is called nutrition.
  7. 7. FibreFoods rich in FibreFibre is also known as roughage. Fibre is made up of cellulose from plant cell walls. Fruits, vegetablesand cereals contain a lot of Fibre. Fibre cannot be digested by our body. Fibre can hold a lot of water sothat our faeces remain soft and can pass from our body easily. Therefore, Fibre can preventconstipation.WaterFoods rich in waterWater makes up about 70 percent of our body weight. Water is the main component of our blood andbody fluid. Water can dissolve a lot of other chemicals in our body and allows these chemicals to react.Waste substances such as urea and salts are passed from our body in water. Water helps to regulate ourbody temperature. However, water loss through urine and sweat must be replaced.
  8. 8. 2.2 The Importance of a Balanced DietDiet refers to all the food we eat each day. We need to have a balanceddiet in order to stay healthy. A balanced diet contains the right amounts of the seven classes of foodto meet the daily requirements of the body. However, a balanced diet foryou may not necessarily be the same for your parents on your friends. Thisis because the amount of food or energy a person needs depends on manyGroup Age (years) Sex Body activity Energy requirements (KJ)Child 5 Female Moderate 6 800 5 Male Moderate 7 600Adolescent 14 Female Moderate 9 200 14 Male Moderate 11 200 25 Female Moderate 8 500 25 Female Active 10 500Adult 25 Male Moderate 9 800 25 Male Active 14 000 65 Female Moderate 6 400 65 Male Moderate 8 600factors such as age, body size, sex, occupation, physical activity, climateand state of health. Table 2.3 shows the daily energy requirements of somepeople.Table 2.3Daily energy requirementsThe energy requirements of children depend on sex. Boys require a slightlyhigher energyintake than girls. The maximum intake is needed at puberty,which occurs around the age of 14. During this period of growth, boysrequire a daily intake of about 11 200 kJ and girls about 9 200 kJ. As forthe adults, makes require a higher daily intake than females because maleshave a smaller amount of fatty tissues in their body. Thus, heat loss isfaster in males than in females. A sedentary worker like the office workerrequires a lower energy intake than a manual worker like a trishaw peddler.
  9. 9. Athletes in serious raining require energy intakes similar to that of manualworkers. People who do not eat a balanced diet can suffer from malnutrition anddeficiency diseases. Sometimes they may have sufficient energy but aredeficient in certain classes of food. Millions of people in the world sufferfrom high blood pressure, osteoporosis and diabetes. People who havehigh blood pressure should avoid foods that are salty and rich in fats.Continuous lack of calcium in a diet may lead to osteoporosis. Diabeticsshould reduce sugar and fat intakes in their diet. Energy valueof foodCarbohydrates, proteins and fats are the supplies of energy. The unit of energy in food can bemeasured in calories (Cal) or (J) where 1 Cal equals 4.2 J. The amount of energy released fromone gram of a particular type of food is known as its calorific value or energy value. Table 2.4shows the energy values of carbohydrates, proteins and fats.Table 2.4 Energy value of carbohydrates, proteins and fatsClass of food Energy value (kJ g-1)Carbohydrates 17Proteins 18Fats 39Food Quantity Calorific Food Quantity Calorific value value (kJ) (kJ)Curry puff 1 piece 168 Low-fat milk 1 glass 543Coffee 1 cup 294 Chocolate milk 1 glass 800Doughnut 1 piece 315 Chicken rice 1 plate 1 273
  10. 10. Egg 1 egg 315 Fried kuih teow 1 plate 1 348Kuih koci 1 piece 344 Egg banjo 1 piece 1 567Banana 1 fruit 378 Soup noodles 1 bowl 1 609Butter 1 tablespoon 399 Nasi lemak 1 plate 1 634White bread 1 slice 420 Curry noodles 1 bowl 2 222Apam balik 1 piece 483 Fried rice 1 plate 2 675Planning a balanced dietTable 2.5 Calorific value of food
  11. 11. 2.3 Human Digestive SystemThe food we eat consists of a minute of carbohydrates, proteins and fats which must bebroken down into smaller molecules. The process of breaking down large foodmolecules into smaller molecules that can be readily absorbed by the body is calleddigestion.Digestion occurs in an eight-metre-long tube called the gut or alimentary canal. The gutbegins at the mouth and ends at the anus. Two other organs, the liver and thepancreas, secrete chemicals to break down the food that we eat. As food passes down the gut, it is broken down into smaller and simpler forms byphysical and chemical digestion. Physical digestion includes chewing by the teeth andthe churning of the food in the stomach. Chemical digestion involves the action ofenzymes on food. Enzymes are substances which act as catalysts and generally speed up thechemical reactions in our body. There are three main kinds of enzymes in our gut.There are:~ Amylase which breaks down carbohydrate molecules such as starch.~ Proteases which break down protein molecules.~ Lipases which break down fat molecules.
  12. 12. Human Digestive SystemMouth~Food is chewed into smaller pieces and mixed with saliva secreted by the salivary glands.
  13. 13. ~Salivary amylase catalyses the breaking down of starch into maltose.Stomach~Stomach wall produces gastric juices which contain proteases and hydrochloric acid.~The hydrochloric acid *stops the action of salivary amylase. *provides an acidic medium suitable for the action of proteases. *changes the inactive forms of proteases to its active forms. *kills bacteria in the food.~Proteases catalyse the breakdown of proteins into polypeptides or peptones.~Mucus protects the stomach walls from being digested by proteases.~Peristalsis in the stomach wall churns the food and mixes it with the gastric juices.Lower part of small intestine~this part of the small intestine secrets intestinal juicewhich contains maltase, protease and lipase.~Maltase breaks maltose into glucose.~Protease breaks down polypeptides into amino acid.~Lipase breaks down fats into fatty acid and glycerol.Duodenum~Duodenum is thefirst part of small intestine. It receives bile from gall bladder and pancreatic juice from pancreas.~Bile is a greenish fluid produced by liver and is stored in gall bladder.~Bile emulsifies fats into oil droplets for lipase to act upon. Bile also neutralizes the acidic chime.~Pancreatic juice contains amylase, protease and lipase.~Pancreatic amylase breaks down starch into maltose.~Protease breaks down proteins into polypeptides.~Lipase catalyses the breakdown of fats into fatty acids and glycerol.Oesophagus~Digested food is shaped into a bolus by the tongue and swallowed.~The bolus moves down the oesophagus in a wave-like action called peristalsis.~Peristalsis occurs when the oesophageal wall contracts and relaxes alternately.2.4 Absorption of Digested FoodBesides digestion, our small intestine is well adapted for the absorption of digested food which consists of smallmolecules. The inner surface of the small intestine is highly folded and has millions of tiny finger-lie projectionscalled villi.
  14. 14. The villi greatly increase the surface area of the small intestine so that absorption of digested food can take placequickly. Digested food is absorbed into the bloodstream mainly by diffusion. Once inside the bloodstream, theabsorbed nutrients are carried to the liver. From the liver, nutrients are sent to the heart and then to all the parts ofthe body.2.5 Reabsorption of Water & DefectionDigestion of food is completed in our small intestine. The residue from the small intestine is mainly water,undigested food, mucus and digested juices. Form here, the water residue moves to the last section of the alimentary
  15. 15. canal- the large intestine. The residue remains in the large intestine for 12 to 24 hours.At the residue passes through the large intestine, a lot of water, together with dissolved minerals and vitamins, isabsorbed into the blood. As much as 6 litres of water is reabsorbed daily. In diarrhoea, less water is reabsorbed. Thiscan lead to dehydration. Severe dehydration can cause low blood pressure, shock or even death.The unusable materials become nearly solid waste called faeces. They are stored in the last part of the largeintestine. Muscular contractions of the walls of the large intestine push the faeces out of the body through the anus.Removal of faeces from the body is called defecation.Eating habits and constipationTo maintain good health, defecation must be done regularly. Difficult in removing undigested food from the body iscalled constipation. This problem is mainly due to unhealthy eating habits-too little fibre and water in the diet aswell as irregular eating hours.Roughage or dietary fibre helps the food pass easily through the digestive system. Without roughage, undigestedfood moves very slowly through the large intestine, thereby losing too much water. It is difficult to pass the hard anddry faeces out of the body. Because the inner lining of the large intestine to bleed. Serious constipation can also leadto haemorrhoids. Constipation can usually be relieved by drinking enough water, eating a high-fibre diet or takinglaxatives.2.6 Healthy Eating HabitsWe will get overweight or obese if we eat too much. Taking too much sugar in our diet may lead to diabetes, too
  16. 16. much salt can cause high blood pressure, a major factor in stroke. Excessive fats can cause high blood cholesterollevels which are associated with heart disease.To healthy eating is to eat a wide variety of foods according to the relative amounts shown in the food pyramid.* Eat in moderation. Food intake should be balanced with physical activity.* Choose nutritious food. Avoid junk food because it is high in calories but lacks nutrients. Usually, highlyprocessed food loses some of its nutrients.* Read food labels. Be an informed consumer.* Do not be misled by food advertisements and unfounded nutrients claims.INDEX
  17. 17. 2.1 Classes of food……………………..………….. 1 *Carbohydrates……….. …………............................................. 2*Proteins………………………………………........................... 2 *Fats…........................................................................................ 3 *Vitamins……………………………………………………… 3-4 *Minerals………………………………………………………. 4-5 *Fibre…………………………………………........................... 6 *Water………………………………………….......................... 62.2 The Importance of a Balanced Diet.................... 7 *Energy value of food………………………………………..... 8 *Planning a balanced diet……………………………………… 82.3 Human Digestive System……………………… 9-102.4 Absorption of Digested Food………………….. 112.5 Reabsorption of Water & Defecation…………..122.6 Healthy Eating Habits………………………….. 13

×