bio p1

• Topics covered


  • Cells
  • Infection and response
  • Organization
  • Bioenergetics
• Animal and plant cells

  Organelles they both have: nucleus, cytoplasm, mitochondria, ribosomes, cell membrane
• Plant cells

  • Vacuole
  • Cell wall made of cellulose
  • Chloroplasts
• Eukaryotic cells

  DNA is inside the nucleus
• Prokaryotic cells

  DNA is not in a nucleus, it's in a plasmid (loop or ring)
• Mitosis

  1. Chromosomes are copied

  2. Chromosomes line up in the middle

  3. Chromosomes are pulled apart

  4. Daughter nuclei form
• Chromosomes in humans

  23 pairs, 46 total
• Meiosis

  1. DNA is copied

  2. Chromosomes swap information

  3. Two daughter nuclei form

  4. Four gametes form with half the information
• Stem cells

  Become specialized into different cell types
• Microscopy

  • Magnification = image size / object size
  • Nanometers are 1 million times smaller than millimeters
  • Micrometers are 1000 times smaller than millimeters
• Electron microscopes

  • Have better resolution than light microscopes, can see organelles
• DNA

  • Made of 4 bases: A, T, C, G
  • 3 bases = code for 1 amino acid
  • Many amino acids = protein
  • Many triplets = gene
• Diffusion

  Particles move from high to low concentration, no energy needed
• Osmosis

  Diffusion of water through a semi-permeable membrane
• Osmosis practical


  1. Cut potato cylinders

  2. Weigh before and after soaking in sucrose solutions

  3. Heavier = water osmosed in, lighter = water osmosed out, no change = equal concentrations
• Active transport


  Moves substances up concentration gradient, requires energy
• Respiration


  Glucose + oxygen -> water + carbon dioxide, releases energy
• Respiration


  Similar to combustion, a slow "burning" of glucose
• Photosynthesis


  Reverse of respiration, uses light energy to produce glucose
• Test for starch


  Add iodine, turns purple
• Photosynthesis rate practical


  1. Measure oxygen bubbles produced by pond weed

  2. Vary light intensity, control temperature and CO2
• Photosynthesis rate graph


  Eventually levels out due to a limiting factor
• Anaerobic respiration


  Produces lactic acid, less ATP than aerobic
• Exercise


  Increases heart rate and breathing rate to get more oxygen
• Metabolism


  Sum of all chemical reactions in the body
• Pathogens


  Bacteria, viruses, fungi, protists that cause infectious diseases
• Defenses against pathogens


  • Skin
  • Platelets
  • Cilia
  • Mucus
  • Acid
  • White blood cells
• White blood cells


  Phagocytes ingest pathogens, lymphocytes make antibodies
• Immunity


  Body remembers how to make antibodies for a pathogen
• Alexander Fleming discovered penicillin, the first antibiotic
• Antibiotics


  • Kill bacteria, don't kill viruses
  • Overuse can lead to resistance
• Drug development


  1. Discovery

  2. Development

  3. Trials (animal, human, blind, double-blind)

  4. Manufacture

  5. Review
• Antibiotic testing practical


  1. Prepare agar plate with bacteria

  2. Add antibiotic discs

  3. Measure zones of inhibition
• Drug development process


  1. Test on tissue

  2. Animal trials

  3. Human blind trials

  4. Double blind trials
• Blind trials


  One group given actual drug, other group given placebo to avoid patient bias
• Double blind trials


  Neither patients nor doctors know which group is control to eliminate bias
• Antibiotic testing process


  1. Prepare agar plate

  2. Spread bacteria like E. coli

  3. Place antibiotic discs on lawn

  4. Measure diameter of inhibition zones
• Aseptic technique


  Using Bunsen flame to prevent contamination
• Monoclonal antibody production


  1. Inject mouse with antigen

  2. Extract antibody-producing white blood cells

  3. Fuse with tumor cells to create hybridomas

  4. Clone and harvest antibodies
• Plant diseases


  • Viruses (e.g. tobacco mosaic virus)
  • Fungi (e.g. rose black spots)
  • Mineral deficiencies (e.g. nitrate, magnesium)