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Nutrition in Animals. Learning Objectives for Nutrition in Animals. Basic Biological Molecules Chemical Digestion The Human Alimentary Canal Absorption & Assimilation. Lesson Objectives. Different Biological Molecules Major Food Groups Food Tests. Biological Molecules. Food Groups
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Learning Objectives for Nutrition in Animals • Basic Biological Molecules • Chemical Digestion • The Human Alimentary Canal • Absorption & Assimilation
Lesson Objectives • Different Biological Molecules • Major Food Groups • Food Tests
Biological Molecules • Food Groups • Food Tests • Biological Molecules
Major Food Groups • Carbohydrates • Proteins • Fats
Food Test Demonstration • Starch (Iodine Test) • Reducing Sugar (Benedict’s Solution Test) • Protein (Biuret Test) • Fat (Ethanol Emulsion Test)
Food Tests Starch (Iodine Test) • Add Iodine to sample.
Food Tests Reducing Sugar (Benedict’s Solution Test) • Add Benedict’s Solution to sample. • Boil mixture for no more than 2 minutes.
Food Tests Protein (Biuret Test) • Add Sodium Hydroxide (NaOH) to sample. • Add Copper II Sulphate (CuSO4) drop by drop.
Food Tests Fat (Ethanol Emulsion Test) • Add Ethanol to sample and shake. • Add Water to mixture and shake.
Biological Molecules • Water • Carbohydrates • Proteins • Fats
Water No one owes Singapore a living • Discuss with your partner and write on: - the importance of water in our lives - methods to conserve water at home/school
Learning Objectives for Nutrition in Animals • Basic Biological Molecules • Chemical Digestion • The Human Alimentary Canal • Absorption & Assimilation
Lesson Objectives • Chemical Digestion • Structure and Functions of Biological Molecules
Reflection time… DO NOT WASTE FOOD
Food for thought. Ingestion Digestion Absorption Assimilation Egestion
Carbohydrates Carbohydrases breaks down carbohydrates into simple sugars (monosaccharide) Polysaccharides=>Disaccharides =>Monosaccharides Chemical Digestion
Carbohydrates • Examples of monosaccharide - glucose, fructose, galactose • Examples of disaccharide - maltose, sucrose, lactose • Examples of polysaccharide - starch (amylose, amylopectin), glycogen
Proteins Proteases breaks down proteins into amino acids Protein => Polypeptide => Amino acids Chemical Digestion
Fats/Lipids Lipases breaks down fats into glycerol and fatty acids Lipid => Glycerol & Fatty Acids Chemical Digestion
Revisiting the Carbohydrates • Examples of monosaccharide - glucose, fructose, galactose • Examples of disaccharide - maltose, sucrose, lactose • Examples of polysaccharide - starch (amylose, amylopectin), glycogen
Revisiting the Carbohydrates Hydrolysis Reaction Carbohydrases breaks down carbohydrates into simple sugars (monosaccharide) Polysaccharides=>Disaccharides =>Monosaccharides Chemical Digestion
Carbohydrates – Condensation Rxn Monosaccharides=>Disaccharides =>Polysaccharides Condensation Condensation
Functions of Carbohydrates • Glucose is required for cellular respiration to provide energy. • Glycogen serves as an energy store.
Revisiting the Proteins Hydrolysis Reaction Proteases breaks down proteins into amino acids Protein => Polypeptide => Amino acids Chemical Digestion
Proteins – Condensation Rxn Proteases breaks down proteins into amino acids Amino Acid => Polypeptide => Protein Weak bonding Condensation
Functions of Proteins • Amino acids are converted into protein to make protoplasm. • Enzymes are made of proteins. • Antibodies are made of proteins. • Excess amino acids are not stored and will be removed via deamination in the liver.
Revisiting the Fats/Lipids Lipases breaks down fats into glycerol and fatty acids Lipid => Glycerol & Fatty Acids Hydrolysis Reaction Chemical Digestion
Functions of Fats/Lipid • Fat is required for the cell membrane. • Adipose tissue helps to insulate the body and keep the body warm. • Adipose tissue also helps protect the vital organs. • Fats are energy store and can be utilised for respiration to provide energy.
Hydrolysis reactions A chemical reaction where a large and complex molecule into 2 smaller and simple molecules. A molecule of water is used up in the process. Condensation reactions A chemical reaction where 2 simple molecules are joined together to form a larger and more complex molecule. A molecule of water is produced in the process. Summary for Nutrients
Carbohydrates Monosaccharide (simple sugar) Disaccharide (double sugar) Polysaccharide (complex sugar) e.g. glucose, galactose, fructose e.g. maltose, lactose, sucrose e.g. starch, glycogen, cellulose Summary for Nutrients
Proteins Amino Acids Polypeptide Chains Proteins e.g. adenine, methionine e.g. enzymes, antibodies Summary for Nutrients
Summary for Nutrients Fats Fatty Acids Fats/Lipids e.g. adipose tissues, phospholipids Glycerol
Learning Objectives for Nutrition in Animals • Basic Biological Molecules • Chemical Digestion • The Human Alimentary Canal • Absorption & Assimilation
Lesson Objectives • Parts of the Human Alimentary Canal • Functions of the Human Alimentary Canal • Peristalsis
Nutrition in Human Ingestion Digestion Absorption Assimilation Egestion
Human Alimentary CanalProcesses and Functions • Ingestion – the process of taking in food into the alimentary canal through the mouth. • Digestion - the process of the breaking down of large, complex and insoluble substances into small, simple and soluble molecules by the action of enzymes; so as to facilitate the absorption of nutrients into the body.
Human Alimentary CanalProcesses and Functions • Absorption – the process where digested food substances are taken up by the body through the blood stream. • Assimilation – the process where the nutrients absorbed are converted into new protoplasm and/or used to release energy for the body
Human Alimentary CanalProcesses and Functions • Egestion – the process where indigestible and unabsorbed material are removed from the alimentary canal through the anus. • Egestion = Excretion* *Excretion is the removal of metabolic waste products from the body through the excretory system (to be covered in later topics)
Salivary glands Oesophagus Buccal Cavity • Food is broken down into smaller bits by chewing (physical digestion). • increases surface area of food substances. • Salivary glands produce salivary amylase that breaks down starch into maltose. • The bolus is swallowed and being pushed along the oesophagus by peristalsis. Salivary amylase Starch → Maltose
Peristalsis Longitudinal muscles Epidermal layer Lumen Circular muscles Antagonistic muscles
Stomach • Gastric juices is secreted into the stomach. • Gastric juices contain hydrochloric acid, pepsin and rennin. • hydrochloric acid kills bacteria. • hydrochloric acid lowers the pH in the stomach (pH 2~3). • pepsin breaks down protein to polypeptides. • rennin curdles the milk. • salivary amylase action stops due to the low pH. (non-optimal pH conditions) Pepsin Protein → Poly-peptides
Liver Gall bladder Bile duct Pancreas Duodenum Small intestine and peripheral organs • Liver makes bile • Bile is stored in gall bladder and secreted into the duodenum via the bile duct. • bile increases the pH (pH 9~10) • bile emulsifies fat. • emulsification of fat increases the surface area for fat digestion. • lipases will break down the fats into fatty acid and glycerol. Lipase Fats → Fatty acid + Glycerol
Liver Gall bladder Bile duct Pancreas Duodenum Small intestine and peripheral organs • Pancreas produces pancreatic juices. • Pancreatic juices are secreted into the duodenum via the pancreatic duct. • pancreatic juices increases the pH (pH 9~10). • pancreatic juices contains pancreatic amylase, pancreatic lipase, and trypsin. • trypsin breaks down protein to polypeptides. • gastric juices actions stop. Trypsin Protein → Poly-peptides
Liver Gall bladder Bile duct Pancreas Duodenum Small intestine and peripheral organs • Small intestine produces intestinal juices. • Small intestine absorbs most of the nutrients at the end of ileum. • intestinal juices contains erepsin, lipases and carbohydrases. • erepsin breaks down polypeptides into amino acids. Erepsin Poly-peptides → Amino acids
colon appendix rectum anus Large intestine, rectum and anus. • Colon absorbs the remaining water content and mineral salts. • Rectum serves as a temporary storage for indigestible material and unabsorbed material. • The anus is the opening where faeces is egested out of the body.
Digestion (pancreatic enzymes) amylase • Starch maltose • Protein polypeptides • Fat fatty acids and glycerol trypsin lipase
Digestion (intestinal enzymes) maltase • Maltose glucose • Polypeptides amino acids • Fats fatty acids and glycerol erepsin lipase