1. Life.pdf

Life Aarni Auerniitty Characteristics of life How do you know something is alive? 1. Order of life  All life follows the same structure  Molecule  Organelles  Cell  Tissue  Organ  Individual  Population  Ecosystem  Biosphere 2. Cell structure  Similar metabolic functi...

Life Aarni Auerniitty Characteristics of life How do you know something is alive? 1. Order of life  All life follows the same structure  Molecule  Organelles  Cell  Tissue  Organ  Individual  Population  Ecosystem  Biosphere 2. Cell structure  Similar metabolic functions and structures from single celled to multicellular organisms 3. Chemical properties  Certain compounds like lipids and DNA are only found from living organisms 4. Information in genes  Genes contain the information required for cell function  As cells divide the information is copied to the new cells 5. Reproduction  Information included in genes is transferred to new generations 6. Life cycle 7. Metabolism  Organisms take matter from around them to produce energy  Unnecessary and harmful compounds are disposed 8. Reacting  Organisms can react and adapt to changes in their environment 9. Self regulation (homeostasis)  Organisms maintain internal physical and chemical equilibrium Metabolism  Photosynthesis 6CO2 + 6H2O + Light (energy)  C6H12O6 + 6O2  Cell respiration C6H12O6 + 6O2  6CO2 + 6H2O + ATP (energy) 10.Evolution  Changes in genes help species to adapt to long term changes in their environment, hide from predation, be better hunters, reproduce more efficiently etc.  Water Specific elements Requirements Sun for life Environmental conditions: suitable pressure, pH, temperature, salt and oxygen content etc. Atmosphere and magnetosphere Water  Excellent solvent  Cohesion and adhesion  High specific heat capacity  High vaporization point  High boiling point  Elements  Five most important elements for life 1. Carbon 2. Hydrogen 3. Oxygen 4. Nitrogen 5. Phosphorus Radiation of the sun  Heat  Visible light for photosynthesis Environmental factors  pH  Salt content  Pressure  Temperature  Oxygen content  Atmosphere and magnetosphere  Providing air to breathe, maintaining the greenhouse effect, protecting against radiation etc.