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• Plant cell


  • Cell membrane - responsible for determining which bits go to in or out of the cell
  • Cell wall - important for structure
  • Vacuole - important for structure
  • Cytoplasm - where most reactions take place
  • Ribosomes - responsible for protein synthesis
  • Chloroplasts
  • Mitochondria - where energy is produced
  • Nucleus
• Animal cell


  • Cell membrane - controlling what goes in and out
  • Mitochondria - where energy is produced
  • Ribosomes - protein synthesis
  • Cytoplasm - where most reactions take place
  • Nucleus - where DNA is held and control center of the cell
• Plant cells have several features that animal cells don't share, e.g. cell wall, vacuole, chloroplasts
• There isn't really a typical type of cell because there are a wide range of differentiated specialized cells
• Differentiation


  When various different genes will be turned on and turned off, and that's when a cell will start to specialize
• Magnification


  Magnification = image height / object height
• Units of measurement


  • Meter (m)
  • Centimeter (cm) - 1 x 10^-2 m
  • Millimeter (mm) - 1 x 10^-3 m
  • Micrometer (μm) - 1 x 10^-6 m
  • Nanometer (nm) - 1 x 10^-9 m
  • Picometer (pm) - 1 x 10^-12 m
• Enzymes


  • Work with the lock and key mechanism
  • Have a specifically shaped active site that only certain substrates can fit into
  • Form an enzyme-substrate complex
  • Break apart or join together substrates
  • Release products and remain unchanged to be used again
• Temperature affects enzyme activity

  • Low temperatures - not enough energy
  • Optimal temperature - peak activity
  • High temperatures - enzymes become denatured
• pH affects enzyme activity

  • Optimal pH
  • Too high or too low pH - enzymes become denatured
• Substrate concentration affects enzyme activity

  Increasing substrate concentration increases enzyme activity until active sites are full, then no further increase
• Digestive enzymes


  • Lipase - breaks down fats, made in pancreas and small intestine, works in small intestine
  • Protease - breaks down proteins, made in stomach, pancreas and small intestine, works in stomach and small intestine
  • Amylase - breaks down starch, made in salivary glands, pancreas and small intestine, works in mouth and small intestine
• Diffusion


  Movement of gases or dissolved particles from high concentration to low concentration
• Osmosis


  Movement of water through a partially permeable membrane from high water concentration to low water concentration
• Active transport


  Movement of substances from low concentration to high concentration, against the concentration gradient
• Cancer


  • Cells divide uncontrollably, leading to lumps (benign or malignant tumors)
  • Benign tumors are slow-growing and generally harmless
  • Malignant tumors are fast-growing, aggressive and can spread to other parts of the body
• Cancer risk factors


  • Smoking
  • Diet
  • Sun exposure
  • Unprotected sex
• Stem cells


  • Have the potential to turn into any other type of cell
  • Can be used to grow new cells/tissues/organs to treat diseases and injuries
• Nervous system


  • Consists of the brain, spinal cord (central nervous system) and neurons, receptors, effectors
  • Transmits electrical signals from receptors to the central nervous system and back to effectors
  • Includes both fast electrical signals and slower chemical signals across synapses
• Advantages of sexual reproduction

  • Genetically diverse population, better protection from diseases
• Advantages of asexual reproduction

  • Only one parent required, energy conserved by not needing to find a mate
• Disadvantages of asexual reproduction

  • Genetically identical population, susceptible to diseases
• Mitosis


  1. DNA condenses into chromosomes

  2. Chromosomes line up in the middle

  3. Chromosomes are pulled apart to the ends

  4. New nuclei form

  5. Cell divides into two identical daughter cells
• Meiosis


  1. Chromosomes line up and undergo crossing over

  2. Cell divides into two

  3. Cell divides again into four genetically distinct daughter cells
• Selfish gene


  The parent is putting all of its energy into conserving its own genes
• Mitosis


  1. DNA condenses into chromosomes

  2. Chromosomes line up down the middle

  3. Chromosomes pulled apart to either end of the cell

  4. New nuclei form

  5. Two identical daughter cells
• Meiosis


  1. Chromosomes line up

  2. Crossing over occurs

  3. Divide into two

  4. Divide into two again

  5. Four different daughter cells
• Mitosis


  Leads to two identical daughter cells
• Meiosis


  Leads to four different daughter cells
• Diploid cells


  Produced by mitosis
• Haploid cells


  Produced by meiosis, have half the number of DNA as the parent cell
• Gametes


  Sex cells, eggs in women, sperm in men
• Pollen


  Male gametes in plants
• Extracting DNA


  1. Mash up

  2. Add salt water

  3. Add detergents

  4. Leave at 60 degrees C for 15 minutes

  5. Filter

  6. Add iced ethanol
• DNA


  Made of A, T, C, G bases that fit together in a double helix structure
• Gene


  Stretch of DNA that codes for a characteristic
• Genome


  All the genes in a body
• Alleles


  Different versions of genes
• Dominant


  Need one gene to express characteristic
• Recessive


  Need two identical recessive genes to express characteristic