Science

• Biomolecules


  Any of the numerous substances that are produced by cells and living organisms
• Elements that make up biomolecules

  • Carbon
  • Hydrogen
  • Nitrogen
  • Oxygen
  • Phosphorus
  • Sulfur
• Major classes of biomolecules

  • Carbohydrates
  • Proteins
  • Nucleic acids
  • Lipids
• Carbohydrates


  • Comprised of carbon, hydrogen and oxygen
  • Commonly known as sugars
  • Can range in size from very small to very large
  • Built into long chains by stringing together smaller units (monomers)
• Monomer


  Single unit forming a long chain of molecules creating a repeated pattern
• Polymer


  Long molecule consisting of many similar building blocks, or a repeated pattern of various building blocks
• Carbohydrate examples


  • Sugars found in milk (lactose)
  • Table sugar (sucrose)
• Carbohydrates


  Chemically defined as polyhydroxy aldehydes or ketones or compounds which produce them on hydrolysis
• Types of carbohydrates by number of sugar units

  • Monosaccharides (1 sugar unit)
  • Oligosaccharides (2-10 sugar units)
  • Polysaccharides (more than 10 sugar units)
• Functions of carbohydrates


  • Excellent source of energy
  • Some have structural function (e.g. cellulose in plants)
  • Stored forms of energy (starch and glycogen)
• Proteins


  • Comprised of carbon, nitrogen, oxygen, hydrogen and sometimes sulfur
  • Polymers of amino acids arranged in the form of a chain called polypeptide
  • Have primary, secondary, tertiary and quaternary structural organization
• Functions of proteins


  • Structural (e.g. hair, nails, muscles)
  • Dynamic (e.g. carriers, channels, enzymes)
• Lipids


  • A wide variety of biomolecules including fats, oils, waxes and steroid hormones
  • Do not dissolve in water, are hydrophobic
• Lipid examples


  • Fats
  • Oils
  • Waxes
  • Steroid hormones
• Functions of lipids


  • Good source of stored energy
  • Form protective layers (e.g. skin)
  • Regulators of cell activity (e.g. steroid hormones)
• Nucleic acids


  • Main information-carrying molecules of the cell
  • Determine the inherited characteristics of living things
  • Comprised of carbon, hydrogen, oxygen, phosphorus and nitrogen
• Types of nucleic acids

  • DNA
  • RNA
• DNA


  Master blueprint for life, genetic material in all free-living organisms and most viruses
• RNA


  Responsible for creating proteins based on information from DNA, genetic material in some viruses and found in all living cells
• Nucleotide


  Building block of nucleic acids, consisting of a nitrogen-containing base, pentose sugar, and phosphate group
• Nitrogen-containing bases


  • Adenine
  • Guanine
  • Cytosine
  • Thymine
  • Uracil
• Monomer


  Single basic building unit of all organic compounds
• What macromolecules do


  • Carbohydrates: energy storage, structure
  • Proteins: storage, signals, structural, defensive, catalyst, transport, receptors
  • Lipids: energy storage, protection, chemical messengers, repel water
  • Nucleic acids: genetic information
• All macromolecules are polymers made up of monomers
• Monomer-polymer pairs


  • Lipids: fatty acids - diglycerides, triglycerides
  • Proteins: amino acids - polypeptides
  • Nucleic acids: nucleotides - DNA, RNA
  • Carbohydrates: monosaccharides - polysaccharides, disaccharides
• Particles in a higher amounts of calamansi extract or laundry concentration bleach removes the stains faster
• In real life, we cannot see molecules. We can feel its presence by tasting, feeling (skin and as eye irritation) and smelling
• Way to visualize how particles are affected by temperature

  1. As the temperature rises, the molecules in hot water move faster and therefore collide more and have greater chances to react with each other than in the cold water

  2. Increasing the temperature increases the rate of reaction

  3. Heating allows more frequent collisions among particles

  4. Most frequent collisions will lead to sufficient energy that will provide necessary activation energy for the reaction to start
• In food preservation, temperature plays a big role in extending the shelf life of foods. This is the reason why perishable foods are chilled or frozen. Decreasing the temperature lowers the rate of spoilage items. Another way to lengthen the shelf life of food is drying. Drying lowers the moisture or water content in food in order to prevent the growth microorganism like bacteria, yeast and molds
• Catalyst


  A substance that alters the rate or speed of chemical reactions
• A catalyst alters the speed of reaction by changing the activation energy
• A catalyst may be recovered unchanged at the end of the process
• Hydrogen peroxide (H2O2) is decomposed naturally and will produce oxygen gas when left exposed but will take a longer time. However, when small amount of MnO2 is added, bubbles can be seen immediately signifying that there is reaction
• A catalyst (enzyme) speeds up a chemical reaction by decreasing the activation energy