5.1 Matter and Energy Pathways in Living Systems

• Photosynthesis


  Chloroplasts in autotrophs convert solar energy to chemical energy and store sugars and other carbohydrates.
• By-products of photosynthesis

  1. Oxygen
  2. Molecules of ATP
  3. Some heat
• What happens during cellular respiration?

  The mitochondria in the cells of plants, animals, and other multicellular organisms break down carbohydrates to generate molecules of ATP.
• What does ATP stand for?

  Adenosine Triphosphate
• What is the source of energy that all organisms use?

  ATP
• What are the cellular activities that ATP supplies energy for?

  1. Active transport of ions and molecules across cell membranes
  2. Moving chromosomes during cell division
  3. Causing cilia and flagella to move
  4. Causing muscles to contract
  5. Synthesizing compounds such as carbohydrates, proteins, fats, and nucleic acids
• How does ATP supply energy for cellular activity?

  When the bond to the third phosphate group in ATP breaks and its energy is released, and the reaction produces ADP.
• What does ADP stand for?

  Adenosine diphosphate - Adenosine + two phosphate groups - and a free phosphate group.
• How is ATP generated?

  By the addition of a free phosphate group to ADP--a process that requires an input of energy.
• Why are plants green?

  They contain chlorophyll, the green-coloured molecules that trap solar energy.
• Where is chlorophyll contained within cell organelles?

  Chloroplasts
• How much chloroplasts do most photosynthetic cells contain?

  40 to 200
• What is the fluid inside a chloroplast called?

  Stroma
• What does the stroma contain?

  Concentrated mixture of proteins and other chemicals that are used in synthesis of carbohydrates.
• The organized and interconnected flattened sacs within the stroma/

  Thykaloids
• What's the structure the thykaloids are stacked up by?

  Grana
• Where are chlorophyll molecules located?

  In the thykaloid membranes of chloroplasts.
• What do the cells of eurkaryotic cells contain?

  Mitochondria
• How many membranes are chloroplasts bound by?

  2
• What is fluid-filled space of the inner membrane called?

  Matrix
• What does the matrix contain?

  Proteins and other chemicals to break down carbohydrates and other high-energy molecules.
• What are the numerous folds of the inner membrane called?

  Cristae
• Equation for photosynthesis

  6CO2(g) + 6H2O + energy -> C6H12O6(s) + O2(g)
• Equation for cellular respiration

  C6H12O6(s) + O2(g) -> 6CO2(g) + 6H2O + energy
• What does photosynthesis use as its starting reactants?

  Products of respiration
• What is metabolism?

  It refers to all the chemical reactions that occur within a cell to support and sustain its life functions.
• What are the two categories that make up metabolism?

  Anabolism and catabolism
• What does the anabolic category do?

  Anabolic molecules pathways synthesize larger molecules from smaller ones and require energy.
• What does the category catabolic do?

  Breaks down large molecules into smaller ones and release energy.
• What process is when an atom or molecule loses an electron and is said to be oxidized?

  Oxidation
• What process is when an atom or molecule gains an electron is said to be reduced?

  Reduction