Biology Mock Yr 10

• Cells


  The basic building blocks of all living organisms
• Tissue


  A group of cells with a similar structure and function
• Organ


  Groups of tissues performing specific functions
• Organ system


  Organs organised to work together to form organisms
• Scale and size of cells

  • Able to use the following scale prefixes: centi, milli, micro and nano
  • Able to change the units from e.g. millimetres to micrometers
  • Able to write answers in standard form
• Eukaryotic cells (plant and animal cells)

  Have a cell membrane, cytoplasm and genetic material enclosed in a nucleus
• Prokaryotic cells (bacterial cells)

  Much smaller in comparison, have cytoplasm and a cell membrane surrounded by a cell wall, genetic material not enclosed in a nucleus but a single DNA loop and possibly plasmids
• Main sub-cellular structures


  • Nucleus
  • Cell membranes
  • Mitochondria
  • Chloroplasts in plant cells
  • Plasmids in bacterial cells
• Parts of most animal cells

  • Nucleus
  • Cytoplasm
  • Cell membrane
  • Mitochondria
  • Ribosomes
• Additional parts of plant cells

  • Chloroplasts
  • Permanent vacuole filled with cell sap
  • Cell wall made of cellulose
• Cell specialisation


  • Sperm cells, nerve cells and muscle cells in animals
  • Root hair cells, xylem and phloem cells in plants
• Electron microscopy


  Has increased the understanding of cell structure
• Magnification


  The ratio of the size of the image to the size of the real object
• Resolution


  The ability to distinguish two adjacent structures as separate
• Electron microscope has much higher magnification and resolving power than a light microscope, enabling study of cells in much finer detail
• Calculating magnification


  1. Magnification = size of image / size of real object

  2. Able to give the answer in standard form if appropriate
• Osmosis


  The diffusion of water from a dilute solution to a concentrated solution through a partially permeable membrane
• Water may move across cell membranes via osmosis
• Active transport


  Moves substances from a more dilute solution to a more concentrated solution (against a concentration gradient), requires energy from respiration
• Active transport allows sugar molecules to be absorbed from lower concentrations in the gut into the blood which has a higher sugar concentration, sugar molecules are used for cell respiration
• Substances transported into and out of cells

  • Diffusion
  • Osmosis
  • Active transport
• Large molecules that living things are made from

  • Carbohydrates: starch, glycogen, cellulose
  • Proteins
  • Lipids
  • DNA
• Required practical activity 3: methods used to test for different carbohydrates, lipids and proteins

  1. Benedict's test for sugars

  2. Iodine test for starch

  3. Biuret reagent for protein
• Smaller molecules that large molecules are made from

  • Sugars (glucose)
  • Fatty acids
  • Glycerol
  • Amino acids
• • Glucose is used to build starch, glycogen and cellulose
  • 3 fatty acids and 1 glycerol can be joined together to form lipids and glucose can be converted into lipids
  • Glucose and nitrate ions are used to form amino acids, and amino acids are used to synthesise proteins
• Metabolism


  The sum of all the reactions in a cell or the body
• Processes included in metabolism

  • Conversion of glucose to starch, glycogen and cellulose
  • Formation of lipid molecules from glycerol and fatty acids
  • Use of glucose and nitrate ions to form amino acids which are used to synthesise proteins
  • Respiration
• Enzymes


  • Catalyse specific reactions in living organisms due to the shape of their active site
  • Students should be able to use the 'lock and key theory' as a simplified model to explain enzyme action
• Students should be able to carry out rate calculations for chemical reactions
• Students should be able to relate knowledge of enzymes to Metabolism
• Required practical activity 4: Investigate the effect of pH on the rate of reaction of amylase enzyme


  1. Measure the time taken to completely digest a starch solution at a range of pH values

  2. Use iodine reagent to test for starch every 30 seconds

  3. Temperature must be controlled by use of a water bath or electric heater
• Cellular respiration


  An exothermic reaction which is continuously occurring in living cells, transfers energy needed for living processes
• Aerobic respiration


  Respiration in cells using oxygen
• Anaerobic respiration


  Respiration in cells without oxygen
• Aerobic respiration is represented by the equation: glucose + oxygen -> carbon dioxide + water
• Anaerobic respiration in muscles is represented by the equation: glucose -> lactic acid
• Anaerobic respiration in plant and yeast cells is represented by the equation: glucose -> ethanol + carbon dioxide
• Anaerobic respiration in yeast cells is called fermentation and has economic importance in the manufacture of bread and alcoholic drinks
• Surface area to volume ratio

  • A single cell or single-celled organism has a relatively large surface area to volume ratio, allowing sufficient transport of molecules into and out of the cell
  • Able to calculate and compare surface area to volume ratios
  • Able to explain the need for exchange surfaces and a transport system in multicellular organisms in terms of surface area to volume ratio
• Diffusion


  The spreading out of the particles of any substance in solution, or particles of a gas, resulting in a net movement from an area of higher concentration to an area of lower concentration