INTRODUCTIONMeaning of nutritionNutrition is the process by which organisms take in and use nutrients.Nutrients are any substances that nourish an organism.Food is any material when taken in absorbed and utilized meet requirement of plant and animal body.The Concepts of Nutrition and Food Nutrients

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The Concept of PhotosynthesisExplain the concept of photosynthesisPhotosynthesis is the process where by green plants manufacture their own food by using light energy produced from the sun. Photosynthesis takes place in plants especially in leaves so as to make their own food by the presence of different factors.FACTORS FOR PHOTOSYNTHESISChlorophyll, carbondioxide, sunlight energy, mineral salts, temperature and water.Equation for photosynthesis:The Structure of the Leaf in Relation to PhotosynthesisDescribe the structure of the leaf in relation to photosynthesisThe petiole or leaf stalk attaches the leaf to the branch or stem. It keeps the lamina in position that will enable it to get a maximum amount of sunlight. The lamina has a large surface area, thus maximizes the absorption of light energy and carbondioxide. The lamina is also thin so that carbondioxide and light energy diffuse over a shot distance to reach cells.The mid rib and veins contain xylem and phloem. Xylem vessels transport water and mineral salt to the leaf. Phloem vessels transport manufactured food to other parts of the plant.The Process of PhotosynthesisExplain the process of photosynthesisIt takes place inside the cell organelles known as chloroplasts. Photosynthesis takes place in two stages the light stage and the dark stage.The Importance of Photosynthesis in the Real Life SituationOutline the importance of photosynthesis in the real life situationImportance of photosynthesis in daily life:

The Basic Food Substances and Their PropertiesMention the basic food substances and their propertiesBasic food substances:CarbohydratesProteinLipidsCARBOHYDRATESIs the kind of food substance nutrients made up of carbon, hydrogen, and oxygen. Example: cassava, maize, rice etc.TYPES OF CARBOHYDRATESMonosaccharideDisaccharidePolysaccharideMONOSACCHARIDE:Monosaccharide is also known as simple sugar. They include glucose, fructose and galactose. These sugars dissolve in water and form sweet solutions. Monosaccharide are reduced sugar. The general formulae for monosaccharide is (CH₂O)nWhere “n” represents a number of carbon atoms and have a value between 3 and 6. Example the formulae of glucose is (C₆H₁₂O₆)DISACCHARIDE:This is the kind of carbohydrate which is formed when two monosaccharide molecules combine.Two glucose molecules combine to form maltose. (C₆H₁₂O₆) + (C₆H₁₂O₆) condensation = C₁₂H₂₂O₁₁+ H₂O some disaccharide are reducing sugars example lactose and maltose , other are non reducing sugar example sucrosePOLYSACCHARIDE:Is the type of carbohydrates formed by condensation involving several monosaccharide Example starch, chitin etcProperties of polysaccharides:They are not soluble in waterThey are non reducing sugarThey are not sweetWhen put in water they form suspension Test YourselfCommon Reagents and Chemicals used to Determine Food PropertiesIdentify common reagents and chemicals used to determine food PropertiesTEST FOR CARBOHYDRATES

DIGESTIVE SYSTEM IN HUMAN BEINGSThe digestive system of human refers to the human alimentary canal and the organs and glands associated with it.Parts of the Human Digestive System and their Adaptive FeaturesIdentify parts of the human digestive System and their adaptive featuresTHE MAIN PARTS OF ALIMENTARY CANALThe main parts are:- Mouth, Oesophagus, stomach, small intestine, (duodenum and ileum), large intestine (colon) and rectum.ADAPTATIONS OF STOMACH TO ITS MODE OF FUNCTIONStomach has sphincter muscles to prevent food from flowing back into the oesophagusStomach has gastric glands, which produce gastric juice for the digestive process.Also in the stomach of a young baby there is renin which coagulates milkStomachs have mucus which protects it from corrosion by digestive enzymesThere is hydrochloric acid for the emulsification of fats and killing of bacteriaADAPTATIONS OF ILLEUM TO ITS FUNCTIONSThe following are the adaptations of ileum to its mode of functions:-It has secretory glands, which produce digestive enzymesIt is connected to the liver by the bile duct which enable the bile to reach ileumIt has finger like projections called villi for the absorption of foodThe ileum is very long to ensure sufficient absorptions of foodThe villi have large network of blood capillaries for transporting absorbed food to all parts of the bodyThe inner lining of the ileum is folded to increase the surface area for absorption Test YourselfThe Digestion Process in Human BeingExplain the digestion process in process in human beingView Teacher NotesDIGESTION PROCESS IN HUMAN BEINGSDigestion is the process by which food is broken down into a form that can be absorbed and used by the body.Digestion process involves two processes, which are mechanical break down of food and chemical break down of food. The mechanical break down of food takes place in the mouth where the food is chewed by teeth so as to reduce it into small pieces.Digestive enzymes achieve chemical break down of food. The digested food is absorbed and assimilated in the body.The digestion process starts in the mouth where food is mechanically broken down by teeth. The presence of food in the mouth stimulates the salivary gland to produce more saliva.FUNCTIONS OF SALIVAHave salivary amylase enzyme that converts starch into maltoseTo moisten the foodTo provide medium for enzyme reactionsHave mucus to lubricate food for easy swallowingSaliva consists of Sodium and Calcium salt to ensure alkaline medium for amylase enzyme Test YourselfDifference Between the Human Digestive System with that of Other MammalsCompare the human digestive system with that of other mammalsView Teacher NotesThe ruminants’ digestive system differs from human digestive system in the following ways:Ruminants have more elaborate system to enable cellulose digestionThe stomach of ruminants have four chambers (rumen, reticulum,omasum, abomasum)The food is regurgitated, chewed, and again then passed to omasum. Test YourselfCommon Disorders and Diseases of the Human Digestive SystemOutline common disorders and diseases of the human digestive SystemDISORDERS AND DISEASE OF THE DIGESTIVE SYSTEMThese include diseases and disorders that affect teeth, oesophagus, stomach, small intestine and large intestinesExamples are:- dental caries, heart burn, ulcers, constipation and flatulence.Dental caries This is commonly referred to as tooth decay. It occurs when bacteria destroy the outer part of the tooth.Heart burn Refers to the burning or painful sensation in the oesophagus. It is caused by regurgitation of hydrochloric acid in the stomach which leads to the irritation of oesophagus.Stomach ulcers Refers to the sore in stomach lining. It is caused by erosion of stomach wall due to enzyme reactions.Constipation Refers to the decrease in frequency of formation of stool. It occurs when the stool becomes dry and hard due to excessive water absorption in the colon.FlatulenceThis is caused by excess gas in the digestive tract Test YourselfCauses, Symptoms, Effects and Control Measures of Common Disorders and Diseases of the Human Digestive System