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• Amino acids


  Building blocks of proteins
• Digesting a complex carbohydrate

  1. Water is added

  2. Simple sugar is obtained

  3. Hydrolysis
• Biomolecules


  The most essential organic molecules, which are involved in the maintenance and metabolic processes of living organisms
• Types of Biomolecules


  • Carbohydrates
  • Proteins
  • Nucleic acids
  • Lipids
• Carbohydrates


  • Chemically defined as polyhydroxy aldehydes or ketones or compounds which produce them on hydrolysis
  • Collectively called as saccharides
  • Classified as monosaccharides, oligosaccharides and polysaccharides
• Monosaccharides


  Carbohydrate monomers, e.g. glucose, fructose, galactose
• Disaccharides


  Two monosaccharides combined, e.g. sucrose, lactose, maltose
• Oligosaccharides


  Carbohydrates formed by the condensation of 2-9 monomers
• Polysaccharides


  Complex carbohydrates formed by the polymerization of a large number of monomers, e.g. starch, glycogen, cellulose
• Starch


  • Composed of two components - amylose and amylopectin
• Glycogen


  • Animal starch, similar structure to starch but more extensively branched
• Cellulose


  • Structural carbohydrate, main component of plant cell walls, forms a linear polymer
• Functions of Carbohydrates


  • Provide energy and food to the body and nervous system
  • Involved in fat metabolism and prevents ketosis
  • Inhibits the breakdown of proteins for energy as they are the primary source of energy
  • Enzyme amylase assists in the breakdown of starch into glucose
• Sources of Carbohydrates


  • Fructose in fruits
  • Galactose in dairy products
  • Lactose in milk and dairy
  • Maltose in cereal, beer, potatoes, etc.
  • Sucrose in sugar and honey
• Good Carbohydrates


  • High in nutrients
  • Moderate in calories
  • Low in sodium and saturated fats
  • Low in trans-fat and cholesterol
  • Complex carbs like legumes, vegetables, whole grains, fruits, beans
• Bad Carbohydrates


  • Low in nutrients
  • High in calories
  • High in sodium and saturated fats
  • High in trans-fat and cholesterol
  • White flour, rice, pastries, sodas, processed foods
• Examples of Carbohydrates


  • Glucose
  • Galactose
  • Maltose
  • Lactose
  • Starch
  • Cellulose
  • Fructose
  • Sucrose
  • Chitin
• Proteins


  • Polymers of amino acids arranged in the form of polypeptide chains
  • Classified into primary, secondary, tertiary and quaternary structures
  • Play both structural and dynamic roles, e.g. myosin allows muscle contraction, most enzymes are proteinaceous
• Saturated fats


  High in trans-fat and cholesterol
• Foods considered bad carbs rarely have any nutritional value. Some of the foods include white flour, rice, pastries, sodas and processed foods.
• Examples of Carbohydrates


  • Glucose
  • Galactose
  • Maltose
  • Lactose
  • Starch
  • Cellulose
  • Fructose
  • Sucrose
• Proteins


  Polymers of amino acids arranged in the form of polypeptide chains
• Protein structure


  • Primary
  • Secondary
  • Tertiary
  • Quaternary
• Proteins


  Perform structural and dynamic roles, e.g. Myosin allows muscle contraction, most enzymes are proteinaceous
• Sources of Proteins


  • Egg
  • Meat
  • Pulses
  • Milk & milk preparations
  • Fish
• Functions of Proteins


  • Enzymes
  • Hormones
  • Antibody
  • Energy
• Nucleic acids


  Genetic material that carries hereditary information, including DNA and RNA
• Nucleotide


  Monomeric unit of nucleic acids, composed of nitrogenous base, pentose sugar, and phosphate
• DNA structure


  • Double-helix formed by hydrogen bonding between bases of two antiparallel polynucleotide chains
• Lipids


  Organic substances that are insoluble in water, soluble in organic solvents, related to fatty acids, and utilized by living cells
• Lipid bilayer


  • Polar heads (hydrophilic) and nonpolar tails (hydrophobic)
• Properties of Lipids


  • Oily or greasy nonpolar molecules
  • Heterogeneous group of compounds mainly composed of hydrocarbon chains
  • Energy-rich organic molecules
  • Soluble in nonpolar solvents and insoluble in water
  • Form mechanical barrier as cell membrane
• Types of Lipids


  • Simple Lipids: Fats, Waxes
  • Complex Lipids: Phospholipids, Glycolipids, Other complex lipids
• Fatty acids


  Carboxylic acids with long aliphatic tails, either unsaturated or saturated
• Saturated fatty acids


  • Lack of carbon-carbon double bonds, higher melting points, straight rod-like shape
• Unsaturated fatty acids


  • Contain cis-double bond(s), create structural kink, unable to pack in straight rod-like shape