Mod 1

• Simple diffusion is when small uncharged particles such as carbon dioxide and oxygen move more easily through the membrane.
• Facilitated diffusion is when large molecules such as glucose and charged particles require assistance to move across the membrane. Eg sodium ions require integral proteins to assist.
• Movement of water happens across the membrane through tiny protein channels called aquaporins, since water is not lipid soluble.
• The anabolic process is when large organic compounds is formed by simpler molecules. this reaction requires energy input -Endergonic
• Catabolic processes break down large molecules to form simpler molecules. This reaction gives off energy - exergonic
• Autotrophs 


  Make own food from inorganic compounds found in soil or the atmosphere.
• Heterotrophs


  Obtain organic compounds by consuming other organisms
• Substances needed by living cells for their functioning are used in two ways:

  • Essential builds blocks - cells and living tissue are made
  • as a source of stored energy
• Organic nutrients are the main supply of engird in living things, also used in the structure of cells.
• Inorganic nutrients are essential as structural parts of cells and tissues.
• Organic chemicals are based on the elements carbon and hydrogen. Many are macromolecules or polymers made by joining many smaller molecules called monomers.
• Lipids:

  • Contain many C and H, and a few O atoms.
  • Fats and oils
  • used as a way to store excess energy food
  • three fatty acids attach to one glycerol molecule to form a lipid
• Function of lipid

  • energy storage
  • structural component of cell membrane
  • essential structural part of hormones
• proteins

  • Main structural chemical of organelles, cells, bone etc
  • Polymers made from amino acids. Each chain of amino acid is called a polypeptide - held by chemical bonds called peptide bonds.
• Proteins

  • structural component in cells and tissues
  • important component of cell membrane
  • some have functional roles such as enzymes
• Monosaccharides are the simple sugars that are the building blocks for the more complex carbohydrates. EG glucose.
• A cell is defined as the basic unit of life
• Cell Theory was developed by Matthias Schleiden and Theodor Schwann in 1839
• Most prokaryotic cells are small and have a large surface area relative to their volume
• Prokaryotic genetic material is contained in an irregularly shaped region called nucleoid
• Cytoplasm consists of cytosol made up of water and contains ions, salts, and organic molecules
• Ribosomes are responsible for the synthesis of proteins
• Gram Staining Technique

  Used to classify bacteria as gram positive or gram negative
• Bacteria have a mesh-like cell wall made of a polymer called peptidoglycan
• Eukaryotic cell characteristics

  • Membrane-bound nucleus
  • Membrane-bound organelles
  • Size range from 10 to 100 micrometres

  
• Two Dutch lens makers made the first compound microscope in 1590

  
• Robert Hooke designed a compound microscope in 1665

  
• Anton Van Leeuwenhoek developed a simple microscope in 1667

  
• Theodor Schwann and Matthias Schleiden proposed the cell theory in 1839
• The electron microscope was invented in 1933
• Light microscope characteristics

  • Magnification up to x1500
  • Can view both living and non-living specimens
• Light microscopes work by passing a beam of light through a specimen
• Light microscopes can magnify objects typically up to x400 to x1000
• Electron microscopes have a magnification of 1000000x
• Light Microscope

  Produces images up to x1500 depending on the lenses
• Light Microscope

  • Can view both living and non-living specimens
  • Uses a beam of light
  • Typical school ones can go up to x400 to x1000
• Structures visible with a light microscope

  • Contains genetic material
  • Forms a boundary between the cytoplasm and external environment
  • Holds cell organelles and chemical reactions
  • Gives protection, support and shape to plant cells
  • Contains chlorophyll for photosynthesis
  • Stores water, salts, starch and other substances in plants
• Electron Microscope

  Uses a beam of electrons to see cells and their contents at high magnification and clarity
• Electron Microscope

  • High magnification
  • High resolution
  • Can reveal structures at a sub-cellular level
• Types of Electron Microscopes

  • Transmission Electron Microscope (TEM)
  • Scanning Electron Microscope (SEM)