Energy transformations

Energy transformations

1. Autotrophs vs Heterotrophs

   • Autotrophs
     • Self feeding
     • Obtain organic compounds by converting inorganic molecules
       • Carbon fixation
     • Types of autotrophs
       • Photosynthetic autotrophs
         • Organisms that obtain energy required for carbon fixation through sunlight
         • All green plants are photosynthetic, as well as some protists like algae
           • The chlorophyll in chloroplasts makes the plants green
       • Chemosynthetic autotrophs
         • Organisms that obtain energy required for carbon fixation through inorganic chemical reactions
   • Heterorophs
     • Other feeders
     • Obtain energy through consuming other organisms or their products
     • All animals and fungi are heterotrophs
     • Types of heterotrophs
       • Herbivores
         • Only eat plants
       • Carnivores
         • Only eats animals
       • Omnivores
         • Eat a mixture of plants and animals
         • Don't specialise in a food source
         • Are opportunistic eaters
           • Means they eat whatever they can
       • Saprotrophs
         • Most fungi and some bacteria
         • Eat by digesting organic material by extraellular methods
           • Secrete enzymes onto material to break them down and then absorb them through endocytosis
       • Parasites
         • Derive energy and nutrients from other living oorganisms
         • The host is usually harmed/ killed organisms
         • Types of parasites
           • Endoparasites
             • Live inside the host
             • Example: Tapeworrm, liver fluke
           • Exoparasites
             • Live outside the host
             • Example: Ticks, lice

2. Cellular respiration

   • Energy = the ability to cause change
     • Cells need energy to carry out their functions
   • Energy exists in cells through chemical energy, which is stored in the bonds that join atoms together
     • When these these bonds are broken their energy is released and stored in ATP molecules