BIO AND CHEM

• Three states of matter


  Arrangement, movement and energy of the particles
• Interconversions between the three states of matter

  1. Names of the interconversions

  2. How they are achieved

  3. Changes in arrangement, movement and energy of the particles
• Dilution of coloured solutions and diffusion of gases


  Can be explained by the results of experiments
• Solvent


  A substance that dissolves other substances to form a solution
• Solute

  A substance that is dissolved in a solvent to form a solution
• Solution


  A homogeneous mixture composed of two or more substances
• Saturated solution


  A solution that contains the maximum amount of solute that will dissolve at a given temperature
• Classifying a substance


  • Element
  • Compound
  • Mixture
• A pure substance has a fixed melting and boiling point, but a mixture may melt or boil over a range of temperatures
• Experimental techniques for the separation of mixtures

  • Simple distillation
  • Fractional distillation
  • Filtration
  • Crystallisation
  • Paper chromatography
• Chromatogram


  Provides information about the composition of a mixture
• Rf values


  Used to identify the components of a mixture
• Practical: investigate paper chromatography using inks/food colourings
• Atom


  The smallest unit of an element that has the chemical properties of that element
• Molecule


  The smallest particle of a substance that retains its chemical and physical properties
• Structure of an atom

  • Positions, relative masses and relative charges of sub-atomic particles
• Atomic number


  The number of protons in the nucleus of an atom
• Mass number


  The total number of protons and neutrons in the nucleus of an atom
• Isotopes


  Atoms of the same element with the same atomic number but different mass numbers
• Practical: investigate food samples for the presence of glucose, starch, protein and fat
• Enzymes


  Biological catalysts that speed up metabolic reactions
• Temperature changes


  Can affect enzyme function, including changes to the shape of the active site
• Practical: investigate how enzyme activity can be affected by changes in temperature
• Changes in pH


  Can affect enzyme function by altering the active site
• Diffusion


  The movement of particles from an area of high concentration to an area of low concentration
• Osmosis


  The movement of water molecules from an area of high water concentration to an area of low water concentration through a semi-permeable membrane
• Active transport


  The movement of substances across a cell membrane from an area of low concentration to an area of high concentration, using energy
• Factors affecting the rate of movement of substances into and out of cells


  Surface area to volume ratio, distance, temperature, concentration gradient
• Practical: investigate diffusion and osmosis using living and non-living systems
• Photosynthesis


  The process by which plants convert light energy into chemical energy in the form of glucose
• Word equation and balanced chemical symbol equation for photosynthesis
• Varying carbon dioxide concentration, light intensity and temperature

  Affect the rate of photosynthesis
• Structure of the leaf

  • Adapted for photosynthesis
• Mineral ions


  Required by plants for growth, including magnesium for chlorophyll and nitrate for amino acids
• Practical: investigate photosynthesis, showing the evolution of oxygen from a water plant, the production of starch and the requirements of light, carbon dioxide and chlorophyll
• Components of a balanced diet

  • Carbohydrate
  • Protein
  • Lipid
  • Vitamins
  • Minerals
  • Water
  • Dietary fibre
• Sources and functions of diet components

  • Carbohydrate
  • Protein
  • Lipid (fats and oils)
  • Vitamins A, C and D
  • Mineral ions calcium and iron
  • Water
  • Dietary fibre
• Energy requirements


  Vary with activity levels, age and pregnancy
• Structure and function of the human alimentary canal

  • Mouth
  • Oesophagus
  • Stomach
  • Small intestine (duodenum and ileum)
  • Large intestine (colon and rectum)
  • Pancreas
• Peristalsis


  The movement of food through the gut