Module 1

• Prokaryotic

  • Structures float in fluid - like cytoplasm
  • Membrane contains what goes in & out of cell
  • Divdied into Bactiera and archaea
• Eukaryotic

  • Organelles carry out biochemical processes (E.g. preparation & photosynthesis)
  • Can be unicellular or multicellular
• What do both Prokaryotes and Eukaryotes have in common?

  • Cell membrane
  • Cytoplasm
  • Ribosomes
• Adhesion Proteins

  Communicate, anchor and place cells to form tridimensional structures
• Transport Proteins

  Passage ways that allow non-lipid soluble molecules/ions to move across membrane
• Receptor Proteins

  • Vary in different cells
  • Certain cells respond to only certain signals from substances, giving specific functions
• Recognition Proteins

  • Glycoproteins
  • Allow immune system to recognise between foreign particles and body's own cells
• Peripheral Proteins

  • Involved in moving substanes within + outside
  • Cell - Cell interactions
• Lipid Bilayer

  • Provides ability to flow and change shape
  • Proteins are embedded within
• Permeability of cell membrane to molecule depends on:

  • molecule: size
  • Electrical charge (low membrane permeability, neutral = high)
  • Lipid solubility
• Simple Diffusion

  • When molecules are able to move freely
  • Move freely across selectively permeable membrane
  • Equilibrium is obtained
• Facilitated diffusion is when molecules require a membrane channel
• Osmosis is diffusion of H2O across the membrane using special membrane channels called aquaporins

  • No energy required
  • Rate dependent on concentration of solute
• Magnification

  The ratio of the size of the image to the size of the object
• Active Transport (ATP)


  Movement of molecules against the concentration gradient from low => high. Assisted by enzymes
• Hypotonic (Hypo-lower) Watery Concentration

  Cells are surrounded by solution of lower solute concentration than cytoplasm => external solution hypotonic
• Isotonic (Iso-same) Inbetween


  Fluids in and outside of cell are of equal solute concentration => external = isotonic
• Hypertonic (Hyper = High) Solute rich ext. envir.

  If cell are surrounded by solution of higher solute concentration => external = hypertonic
• Endocytosis

  • Movement of large molecules using energy
  • Membrance changes shape
  • Surrounds and engulfs vesicle
• Exocytosis

  • Membrane-bound vesicle fuses with external environment
• Passive Transport 


  Movement of molecules requiring no energy as they move down the concentration gradient
• Active Transport always happens through a carrier protein

  • Push against concentration gradient
  • Requires ATP energy
• Bulk transport occurs when molecules such as proteins are too large to go through another protein
• Bulk Transport (Endocytosis)

  • Formed by the membrane itself
• Bulk Transport (Exocytosis)

  • Fuses with the membrane
• Endocytosis - Engulfment of particles by the membrane creating a vesicle

  • Engulfment of a solid particles = Phagocytosis (Cell-eating)
  • Engulfment of a fluid = Pinocyotsis (Cell-drinking)
• Exocytosis - Membrane-bound vesicle fuses with membrane and releases contents to exterior environment
• Why are cells so small?

  • Maximise surface area in relation to volume
  • Transport things in/out of the cell
  • Small volume do not travel far distances
  • Increased rate of diffusion
• Larger the cube = Small ratio

  Size of cube = Larger ratio
• Organic Substance Definition

  Compounds composed of Carbon w/ H, O, N
• Organic Substance Example

  Glucose, Amino acids, Fatty acids and glycerol, Nucleotides, Vitamins
• Inorganic Substance Definition

  Compounds that do not contain C, usually
• Inorganic Substance Examples

  Gases (O2, CO2), minerals, (Phosphates, sodium + chloride ions) and Water (H2O)
• Autotrophs (Producers)

  • Organisms that make their food
  • Take inorganic substances and make them organic
• Heterotrophs


  Consume organic matter
• Carbohydrates

  • Monomer (Building blocks)
  • Monosaccharides
  • Elements: C, H, O
  • Important sources of energy
• Lipids

  • Monomer: Fatty Acids & Glycerol
  • Elements: C, H, O
  • Insulation + energy
  • Make up cell membrane (Living things)
• Proteins

  • Monomer: Amino Acids
  • Elements: C, H, O, N
  • Build muscles
  • Work as enzymes
  • Antibody prot. immunes
• Nucleic Acid

  • Monomer: Nucleotides
  • Elements: C, H, O, N, P
  • DNA: Code molecule for proteins in nucleus
  • RNA: Convert info in DNA into proteins
  • ATP: Captures chemical energy from food molecules
• Metabolism (Chemical reactions in cells) produces by-products