Energetics: Photosynthesis, Aerobic vs Anaerobic Respiration

• Energy


  Ability to do work
• Energy for living things

  Comes from food
• Almost all energy on this planet comes from the sun
• First Law of Thermodynamics

  The energy of the universe is constant, energy can be transferred and transformed, energy cannot be created or destroyed, it's conserved
• Second Law of Thermodynamics

  Every energy transfer or transformation increases the entropy (disorder) of the universe, during every energy transfer or transformation, some energy is unusable, often lost as heat
• We must have a constant supply of energy from the sun
• Metabolism


  The total of an organism's chemical reactions, due to catabolic and anabolic reactions, manages the materials and energy resources of a cell in many tiny steps
• Homeostasis


  The balance of metabolic reactions, food, water, chemicals, temperature, pressure etc.
• Photosynthesis


  An anabolic reaction, it forms bonds between molecules by creating/synthesizing
• Cellular Respiration


  A catabolic reaction, it breaks bonds between molecules (breaks down sugar for energy)
• Autotrophs


  Organisms that use energy from the sun or heat to produce food
• Photosynthesis


  Uses the sun's energy with CO2 + H2O to make sugar, done by plants, some bacteria, and some protists
• Chemosynthesis


  Uses chemicals/heat from the earth, done by rare creatures (bacteria/archaea)
• Heterotrophs


  Organisms that cannot use the sun's energy to make food, they must take it
• Energy transfer


  Energy comes from the sun, photosynthesis stores that solar energy into bonds of sugar, cellular respiration breaks those bonds to make the energy currency of the body: ATP
• ADP


  Adenosine diphosphate
• ATP


  Adenosine triphosphate, energy is stored here between the 2nd and 3rd phosphate
• Using ATP energy


  Transport/move things, mechanical work (muscle movement), allow chemical reactions to happen, keep warm
• Photosynthesis is the process by which the energy of sunlight is converted into the energy of glucose
• Chloroplasts


  Where photosynthesis occurs in plants
• Chlorophyll


  The pigment inside the chloroplast that absorbs light for photosynthesis
• Light Dependent Reaction/Photolysis


  H2O is broken down and light energy is stored temporarily in inorganic energy carriers, ATP and NADPH
• Calvin Cycle (light independent)


  Energy is transferred from ATP and NADPH to the organic compound glucose
• Cellular Respiration


  Occurs in all cells and can take place either with or without oxygen
• Types of Cellular Respiration

  • Anaerobic (without oxygen), Aerobic (with oxygen)
• Cellular Respiration


  The process by which the energy of glucose is released in the cell as ATP to be used for life processes
• Anaerobic Respiration


  Glycolysis, Alcoholic fermentation, Lactic acid fermentation
• Aerobic Respiration


  Glycolysis, Krebs Cycle, Electron Transport Chain
• Anaerobic Respiration produces much less ATP than Aerobic Respiration
• Lactic acid fermentation


  Occurs in muscle cells, produces lactic acid, causes burning sensation in muscles
• Alcoholic fermentation


  Occurs in bacteria and yeast, used in baking and brewing industry, produces CO2 gas
• Seasons impact CO2 concentration

  Within one year, CO2 concentration goes up and down
• CO2 concentration climbing over past decades


  Reason: ?
• Weightlifter using heavy weights in short bursts gets muscle fatigue
• Plants use both cellular respiration and photosynthesis


  Since plants don't consume other creatures, cellular respiration and photosynthesis are related in terms of energy
• Species X always produces CO2 and H2O during cellular respiration, Species Y always produces ethyl alcohol and CO2
• Function of ATP


  Transport/move things, mechanical work (muscle movement), allow chemical reactions to happen, keep warm