biology

• You need to be familiar with all of the different structures within a eukaryotic cell both plant cells and animal cells and the function of all of those different organelles
• Organelles found in both plant and animal eukaryotic cells

  • Nucleus
  • Cell surface membrane
  • Mitochondria
  • Ribosomes
  • Golgi apparatus
• Organelles found only in plant eukaryotic cells


  • Chloroplasts
  • Cell wall
  • Vacuole
• Nucleus


  • Where chromosomes are located
  • Enclosed by a nuclear envelope
  • Controls the cell's activity
  • Contains the nucleolus where ribosomes are produced
• Cell surface membrane


  • Made up of lipids and proteins
  • Controls movement of things in and out of the cell
• Mitochondria


  • Have a double membrane
  • Highly folded inner membrane
  • Site of enzymes involved in respiration and ATP production
• Ribosomes


  • Small structures where proteins are made
  • Can be found on the rough endoplasmic reticulum or in the cytoplasm
• Golgi apparatus


  • Fluid-filled membrane
  • Produces and transports new lipids and proteins
• Chloroplasts


  • Site of photosynthesis
  • Have a double membrane
  • Contain thylakoid membranes
• Cell wall


  • Ensures cell structure is maintained
• Vacuole


  • Contains sap
  • Helps maintain cell shape and structure by maintaining pressure
• Rough endoplasmic reticulum


  • Site of protein synthesis and processing
• Smooth endoplasmic reticulum


  • Site of lipid synthesis and processing
• Lysosomes


  • Contain digestive enzymes
• Cytoplasm


  • Where most cell reactions take place
• Eukaryotic cells have physical adaptations to maximise diffusion, such as microvilli and concave shapes
• Cells adapted for storage can have large lipid stores or vacuoles
• Secretory cells are adapted to have large Golgi apparatuses and rough endoplasmic reticulum
• Cells with high energy requirements are adapted to have many mitochondria
• Cells with high active transport requirements are adapted to have many channel and carrier proteins, as well as increased ribosomes
• Structures found in prokaryotic cells

  • Cytoplasm
  • Ribosomes
  • Cell surface membrane
  • Cell wall
  • Flagella
  • DNA (not in nucleus)
  • Plasmid DNA
• Millimeter


  1/1000 of a meter
• Micrometer


  1/1000 of a millimeter
• Nanometer


  1/1000 of a micrometer
• To convert between millimeters, micrometers and nanometers: multiply by 1000 to go from millimeters to micrometers, then multiply by 1000 again to go from micrometers to nanometers. To go the other way, divide by 1000.
• Differences between optical and electron microscopes

  • Optical microscopes use light, electron microscopes use electrons
  • Optical microscopes can view living specimens, electron microscopes require fixed specimens
  • Optical microscopes have lower maximum magnification, electron microscopes have higher maximum magnification
  • Optical microscope images are in colour, electron microscope images are black and white
• Optical microscope components


  • Eyepiece
  • Base with light source
  • Coarse and fine focus knobs
  • Objective lenses
  • Stage to hold slide
• Optical microscope lenses


  • Convex glass lenses
  • Eyepiece and objective lenses
• Resolution


  The ability to differentiate between two spots
• Optical microscopes have a resolution limit of around 0.2 micrometers
• Transmission electron microscope


  • Very high resolution
  • Requires very thin specimens
  • Uses fixed, dead samples
• Scanning electron microscope


  • Lower resolution than transmission
  • Can produce 3D images
  • Uses fixed, dead samples
• Electron microscopes are very large, require dedicated rooms and air conditioning
• Magnification


  The size of the image divided by the actual size of the object
• When calculating magnification, convert all measurements to the same unit (e.g. micrometers)
• Biological drawings


  • Use a sharp pencil
  • Include a scale
  • Use clear, continuous lines
  • No shading
  • Include a title
  • Accurately represent the subject
• Types of biological bonding

  • Covalent bonding
  • Ionic bonding
  • Hydrogen bonding
• Covalent bonding


  Sharing of electrons between two non-metals
• Ionic bonding


  Transfer of electrons from a metal to a non-metal, forming positive and negative ions
• Hydrogen bonding


  Weak attraction between opposite dipoles