biology 1.6

• Types of nutrition in bacteria

  • Heterotrophic
  • Autotrophic
• Decomposers


  Bacteria that obtain their organic molecules by consuming decaying or dead matter
• Fungi


  • Microscopic and multicellular, eukaryotic and possess cell walls
  • Examples include certain moulds, yeast, mushrooms, and toadstools
  • Do not possess chlorophyll and are heterotrophs
• Types of fungi based on nutrition

  • Decomposers
  • Parasites
• Protista


  The first animal, reflecting the original discoveries and thoughts concerning this most diverse and large group of unicellular organisms
• Groups of protists


  • Amoeba
  • Flagellates
  • Ciliates
  • Sporozoans
• Algae


  • Autotrophic, carry out photosynthesis
  • Vary in size from unicellular and microscopic to large multicellular kelps and seaweeds
  • Inhabit both marine and freshwater environments
  • Important as producers in aquatic food webs and produce about half of all the oxygen on Earth
• The classification of algae is not universally agreed amongst scientists and sometimes, some types of algae are classified as protists
• Archaea


  • Inhabit extreme habitats from high to low temperatures and highly saline environments
  • Can use inorganic molecules like hydrogen sulphide as a source of energy
  • Prokaryotes like bacteria
• Viruses


  • Not alive as they cannot carry out life's processes
  • Non-cellular but contain nucleic acids (DNA or RNA)
  • Can only reproduce inside the cell of a host organism and often cause disease
• Under ideal conditions, bacteria can produce enormous numbers of daughter cells through binary fission in a very short time
• Essential requirements for bacterial growth

  • Nutrients
  • Temperature
  • Acidity/alkalinity (pH)
  • Oxygen
  • Water
  • Energy requirements
• Thermophiles


  Bacteria that live in high temperatures
• Aerobic bacteria


  Require oxygen for life
• Anaerobic bacteria


  Do not require oxygen
• Bacteria need essential matter to provide them with the required elements such as carbon, nitrogen, sulphur and phosphorus
• Inorganic nutrients lack carbon and organic nutrients contain carbon
• Most disease-causing bacteria flourish from about 30°C to 40°C
• Most bacteria have optimal growth with a pH of 7.2-7.4
• Bacteria need moisture to survive, there needs to be the correct water/solute balance
• Bacteria can carry out fermentation, aerobic respiration and photosynthesis
• Intestinal bacteria


  • Produce substances that can inhibit or destroy potentially dangerous or pathogenic bacteria, and enzymes capable of destroying bacterial toxins
  • An important component of a robust, balanced immune system
• Bacteria commonly found in the human intestine

  • Enterococcus spp.
  • Bifidobacterium spp.
  • Lactobacillus spp.
  • Escherichia coli