Biology 1115 Chapter 8

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Biology 1115 Chapter 8
2013-10-17 15:25:51

An introduction to Metabolism
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  1. The cell _____ and _________ to perform work.
    Extracts energy and applies energy
  2. What is Metabolism?
    • is the totality of an organisms chemical reactions.
    • is an emergent property of life that arises from interactions between molecules within the cell
  3. What does an organism's metabolism do?
    It transforms matter and energy.
  4. What is a metabolic pathway? How is it catalyzed?
    • It begins with a specific molecule and ends with a product
    • each step is catalyzed by a specific enzyme
  5. What are the two types of metabolism? Define them.
    • Catabolic pathways: release energy by breaking down complex molecules into simpler compounds
    • Anabolic Pathways: consume energy to build complex molecules from simpler ones
  6. What is an example of catabolic and anabolic pathways?
    • Catabolic pathways: glycolysis
    • Anabolic Pathways: photosynthesis
  7. What is energy?
    The capacity to cause change
  8. Define kinetic energy.
    It's energy associated with motion.
  9. Define heat (thermal energy).
    Is kinetic energy associated with random movement of atoms or molecules.
  10. Define potential energy.
    is energy that matter possess because of its location or structure.
  11. What is chemical energy?
    is potential energy available for release in a chemical reaction.
  12. Energy can be ________ from one form to another.
  13. What is thermodynamics?
    • is the study of energy transformations.
  14. What is a closed system?
    is isolated from its surroundings.
  15. What is an open system?
    energy and matter can be transferred between the system and its surroundings.
  16. Are organisms considered closed or open systems?
    open systems
  17. What is the first law of thermodynamics? What is another name for it?
    • Energy can be transferred and transformed, but it cannot be created or destroyed.
    • the first law is also called the principle of conservation of energy 
  18. During every energy transfer or transformation, some energy is __________ and is often lost as _____.
    • unusable
    • heat
  19. What is the second law of thermodynamics?
    Every energy transfer or transformation increases the entropy (disorder) of the universe.
  20. Living cells convert _______ of energy into heat/
    organized forms
  21. cells create ____________ from less ordered materials.
    ordered structures.
  22. Energy flows into an ecosystem in the form of _______ and exists in the form if _______.
    • light
    • heat
  23. Entropy may decrease in an organism, but the universes total entropy ___________.
  24. Define spontaneous. How does it happen?
    • Happening or arising without apparent external cause; self-generated
    • occurs without energy input, they can happen quickly or slowly
    • energetically favourable
    • increases entropy of universe
  25. What is free energy?
    is energy that can do work when temperature and pressure are uniform, as in a living cell.
  26. What does free energy change tell us?
    Free energy change of a reaction tells us whether or not the reaction occurs spontaneously
  27. Total energy = ___________ + ____________
    • usable energy
    • unusable energy
  28. what is the equation for change in free energy (delta G)?
    Change in total energy (delta H) minus [Temperature in Kelvin times change in entropy (delta  S)]
  29. What processes are spontaneous?
    • Only processes with a negative Delta G  are spontaneous
    • start to finish delta G is "downhill"
  30. What is free energy a measure of?
    is a measure of a system's inability, it's tendency to change to a more stable state.
  31. What happens to free energy and the stability of a system during a spontaneous change?
    • free energy: decreases
    • stability of a system: increases
  32. Define Equilibrium.
    is a state of maximum stability
  33. A process is spontaneous and can perform work only when it's ____________
    moving toward equilibrium
  34. what is an exergonic reaction?
    • proceeds with a net release of free energy and is spontaneous.
    • exothermic reactions
  35. What is an endergonic reaction?
    • absorbs free energy from its surroundings and is not spontaneous
    • endothermic reaction