Biology EOYs

• Photosynthesis word equation


  carbon dioxide + water ---sunlight/chlorophyll---> glucose + oxygen

  
• Photosynthesis symbol equation


  6CO2 + 6H2O ------> C6H12O6 + 6O2

  
• Photosynthesis


  process by which plants and some other organisms use light energy to convert water and carbon dioxide into oxygen and high-energy carbohydrates such as sugars and starches

  
• What do plants use glucose for?

  For Respiration

  Convert to insoluble starch for storage

  To produce fats or oils for storage

  Produce cellulose for cell walls

  Produce amino acids for photosynthesis (also need nitrate ions)

  
• Leaf diagram


  Upper epidermis

  Palisade cells of mesophyll

  Vein (xylem and phloem)

  Spongy cells of mesophyll

  lower epidermis

  cuticle

  guard cells around a stoma

  
• upper epidermis


  the part of the leaf above the palisades layer that prevents the loss of water
• Palisade mesophyll cells


  cells present in plant leaves primarily responsible for photosynthesis
• xylem and phloem


  two types of vascular tissue
• spongy mesophyll cells


  the cells inside the leaf of a plant where gas exchange takes place
• lower epidermis


  protective layer on the bottom of leaf which contains stomata & guard cells
• Cuticle


  The waxy, waterproof layer that covers the leaves and stems of most plants.
• Stomata


  Small openings on the underside of a leaf through which oxygen and carbon dioxide can move
• Guard cells


  control the opening and closing of stomata
• Limiting factors of photosynthesis

  light intensity, carbon dioxide concentration and temperature

  
• Levels of Organisation


  • Cell
  • Organelle
  • Organs
  • Organ systems
  • Tissue
• Cell


  The basic building block of all living organisms
• Organelle


  A specialised structure found inside a cell
• Organs


  Aggregations of tissues performing specific functions
• Organ systems


  Groups of organs that work together to form organisms
• Tissue


  A group of cells with a similar structure and function
• Cell differentiation


  The process by which a cell becomes specialised to its function
• Cell membrane


  A partially permeable barrier that surrounds the cell
• Cell wall


  An outer, structural layer that surrounds some cells. In plant cells, it is made of cellulose. In fungi, it is made of chitin.
• Chloroplast


  An organelle which is the site of photosynthesis
• Cytoplasm


  A jelly-like substance that contains all the organelles of the cell, dissolved nutrients and salts
• Mitochondria


  An organelle which is the site of respiration
• Nucleus


  An organelle found in most eukaryotic cells that contains the genetic material of the cell and controls the activities of the cell
• Ribosomes


  Organelles that are the site of protein synthesis
• Stem cell


  An undifferentiated cell that can divide to produce many specialised cells of the same type
• Active site


  Part of the enzyme that is complementary to the shape of the substrate. The shape of the active site may change if the enzyme is exposed to high temperatures or extremes of pH.
• Amino acids


  Small molecules from which proteins are assembled
• Enzymes


  Biological catalysts that increase the rate of reactions in living organisms
• Glycogen


  A large carbohydrate made from many glucose molecules joined together. It serves as an energy store in animals.
• Lipids


  A group of large molecules that are made from long fatty acid chains and glycerol. Lipids include fats and oils.
• Proteins


  Large molecules made up of amino acids
• Starch


  A large carbohydrate molecule made up of many glucose molecules. It contains the elements carbon, oxygen and hydrogen. It is an energy storage molecule in plants.
• Aerobic respiration - A form of respiration that uses oxygen to release energy from the breakdown of molecules like glucose. Represented by the following word equation:

  glucose + oxygen --> carbon dioxide + water
• Anaerobic respiration - A form of respiration that releases energy from the breakdown of molecules like glucose without using oxygen. Represented by the following word equation:

  glucose --> lactic acid
• Carbohydrates

  • They are made of carbon, oxygen and hydrogen.

  They are polymers that break down into simple sugars

  Proteins

  They are made of carbon, oxygen, hydrogen, sulfur, nitrogen and phosphorous.

  They are polymers that are broken down into its monomers: amino acids

  Lipids

  • Lipids (fats and oils) are made of carbon, oxygen and hydrogen.

  • They are large polymers that are broken down into 3 fatty acids molecules and a glycerol molecule.
• Test for glucose


  1. Add the sample solution into a test tube

  2. Add drops of Benedict's solution into the test tube

  3. Heat in a water bath at 60-70°C for 5 minutes

  4. Take test tube out and record the colour