b1-4

• Electron microscopes


  Have higher resolving power or resolution, allowing finer details to be visualized like cell organelles and subcellular structures
• 5 micrometers in standard form

  5 * 10^-6 meters
• Subcellular structures or organelles only found in plant cells


  • Chloroplasts
  • Permanent vacuole
  • Cell wall
• Eukaryotic cells


  DNA is found in the nucleus
• Prokaryotic cells


  DNA is not found in a nucleus
• Diploid human cells


  Have 23 pairs or 46 chromosomes
• Haploid human cells


  Have 23 chromosomes
• Osmosis


  Diffusion of water through a semi-permeable membrane to balance the concentration of solutions on either side, water moves into the higher concentration solution to dilute it
• Active transport


  Movement of molecules from a low concentration to a high concentration against the concentration gradient, requires energy
• Factors that increase the rate of diffusion or osmosis

  • Increase temperature
  • Increase difference in concentrations
  • Increase surface area
• Finding the concentration of sugar inside a potato in an osmosis practical


  Interpolate using a line of best fit where it crosses the x-axis, this concentration is the same as that inside the potato cells
• Role of bile


  Made by the liver, stored in the gallbladder, then goes to the small intestine where it emulsifies lipids/fats to form small droplets, increasing surface area for enzymes to break them down
• Amylase


  Enzyme secreted by salivary glands and pancreas that breaks down starch into glucose
• Villi


  Cells in the small intestine that absorb nutrients into the bloodstream, have a large surface area to increase the rate of absorption
• Enzymes


  Biological catalysts that facilitate crucial processes in the body, such as breaking down polymers into monomers
• Enzyme specificity


  Enzymes only break down certain molecules due to their lock and key nature, only specific substrates will bind to the enzyme's active site
• Factors that increase enzyme activity

  • Increasing temperature (up to an optimum)
  • Optimum pH
• Enzyme denaturation


  When the active site changes shape and the enzyme no longer works, can be caused by extreme temperature or pH
• What do carbohydrases break down?

  • Carbohydrases break down carbohydrates into simple sugars
• How do you know when amylase has broken down all the starch?

  
  

  The solution will no longer turn black or change colour when added to iodine
• What's the test for starch?

  • Starch - Iodine turns from orange to black
• Alveoli


  Air sacs in the lungs where gas exchange takes place, have a large surface area to maximize the rate of diffusion of oxygen and carbon dioxide
• Red blood cells


  Transport oxygen around the body via the bloodstream, oxygen binds to the hemoglobin inside, their biconcave shape maximizes surface area
• What's the food test for sugars?

  • Sugars - Benedict's solution turns from blue to orange and maybe green in between
• What's the food test for protein?

  • Protein - Biuret reagent turns from blue to purple
• What's the food test for lipids?

  • Lipids - Cold ethanol turns cloudy
• What do proteases beak down?

  Proteins into amino acids
• What do lipases break down?

  lipids/fats into fatty acids and glycerol