Energy enzymes & metabolism

  1. All forms of energy can be placed in two categories name them:
    • Potential energy
    • Kinetic energy
  2. Potential energy
    Is stored energy such as chemical bonds, concentration gradient, charge imbalance, etc
  3. Kinetic energy
    the energy of movement
  4. Metabolism
    sum total of all reactions in an organism
  5. anabolic reactions
    complex molecules are made from simple molecules; energy input is required
  6. catabolic reactions
    complex molecules are broken down to simpler ones and energy is released
  7. First law of thermodynamics
    energy is neither created nor destroyed. When energy is converted from one form to another, the total energy before and after the conversion is the same
  8. Second law of thermodynamics:
    When energy is converted from one form to another, some of that energy becomes unavailable to do work.
  9. No energy transformation is 100% _____
  10. Entropy
    a measure of the disorder in a system
  11. It takes energy to _____ ____ on a system. Unless energy is applied to a system, it will be _____ ______
    • impose order
    • randomly arranged or disordered
  12. ΔG=
  13. If ΔG is negative...
    If ΔG is positive...
    • If negative, free energy is released
    • If positive, free energy is consumed
  14. Exogernic
    reactions release free energy aka (-G): Catabolism/ complexity decreases/ entropy increases
  15. Endergonic
    reaction consumes free energy (+G): anabolism/ complexity (order) increases
  16. ATP ____ & ____ free energy
    captures and transfers
  17. ATP releases a large amount of energy when _____
  18. ATP can_______ or donate phosphate groups to other molecules
  19. ____ is a nucleotide whose hydrolysis yields free energy
  20. ATP+H2O→
    ADP+Pi+free energy
  21. The formation of ATP is ______
  22. Formation and hydrolysis of ATP couples ____ & _____ reactions
    exergonic and endergonic reactions
  23. Exergonic reactions (3)
    • releases energy 
    • cell respiration
    • catabolism
  24. Endergonic reactions (4)
    • requires energy 
    • active transport
    • cell movement 
    • anabolism
  25. Enzymes
    Catalysts that speed up the rate of a reaction without being altered by the reactions
  26. Most biological catalysts are _____ (_____) that act as a framework in which ______ can take place
    • enzymes (proteins)
    • reactions
  27. Activation energy changes the reactants into ____ forms with ____ free energy. These forms are called _____ ____ _____
    • unstable 
    • higher 
    • transition state intermediates
  28. Activation energy can come from _____ the system. The reactants will have more _____ energy
    • heating 
    • kinetic
  29. How do enzymes lower the energy barrier
    By bringing reactants together
  30. What holds the enzyme substrate complex together? (3)
    • hydrogen bonds 
    • electrical attraction
    • covalent bonds
  31. enzyme + substrate (will end up)=
    enzyme + product
  32. The enzyme may change when bound to the substrate, but?
    returns to its original form
  33. The possible ways the enzyme-substrate complex can be formed
    • Orientation
    • Physical strain
    • Chemical charge
  34. How do enzymes orient substrate molecules?
    by bringing together the atoms that will bond
  35. Physical strain
    Enzymes can stretch the bonds in substrate molecules, making them unstable
  36. Chemical charge
    Enzymes can use electrostatic attraction to temporarily add chemical groups to substrates
  37. Shape of enzyme active site allows? (lock and key)
    a specific substrate to fit
  38. Binding of substrate to the active site depends on? (3)
    • Hydrogen bonds
    • attraction and repulsion of electrically charged groups 
    • hydrophobic interactions
  39. Many enzymes change shape when they bind to the substrate, this is called ____ __
    induced fit
  40. The rate of catalyzed reaction depends on _____ ____
    substrate concentration
  41. _______ of an enzyme is usually much _____ than ______ of a substrate.
    • Concentration 
    • lower
    • concentration
  42. At ______, all of the enzyme is bound to the substrate (______ ____)
    • saturation 
    • (maximum rate)
  43. Inhibitors
    regulate enzymes by binding to it and slowing reaction rates
  44. Which inhibitors regulate metabolism
    naturally occurring inhibitors
  45. Reversible inhibition
    inhibitor bonds noncavalently to the active site and prevents substrate from binding
  46. competitive inhibitors
    compete with the natural substrate for binding sites
  47. When concentration of competitive inhibitor is reduced, what happens
    it detaches from the active site
  48. Noncompetitive inhibitors
    bind to the enzyme at a different site (not the active site)
  49. Irreversible inhibition
    Inhibitor covalently bonds to side chains in the active site, this permanently inactivates the enzyme
  50. Initial symptoms poison by nerve gas
    • runny nose
    • tightness of breath
    • constriction of pupils
  51. intermediate symptoms of poison via nerve gas
    • nausea
    • drooling 
    • loss of bodily functions
    • vomiting
  52. final symptoms of poison via nerve gas
    • twitching and jerking 
    • suffocation (death)
  53. Antidote for nerve gas poisoning
    Atropine, a muscarinic ACTH receptor which is a competitive antagonist
  54. Every enzyme is most active at a particular pH. Why is this? Give an example
    • pH influences the ionization of functional groups
    • Ex: at low pH COO- may react with H+ to form COOH (uncharged). This affects folding and thus enzyme function.
  55. Give two reasons why enzyme have an optimal temprature
    At high temps, noncovalent bonds begin to break & enzymes can lose its tertiary structure and become denatured
  56. Phenyletonuria (PKU)
    Genetic disorder due to a mutation in the gene for phenylalanine hydroxylase (PAH)
  57. PAH is required to degrade excess ______ to the amino acid _____. Without this conversion _____ is converted to ________. This leads to (2)?
    • phenylalanine 
    • tyrosine
    • phenylalanine
    • phenylpyruvate

    Leads to: mental disability & seizures
  58. Phenylalanine conversion to phenylpyruvate can be treated by
    eliminating soda from diet
  59. Which has more potential energy, glucose or carbon dioxide?
    Glucose, because it has a lot more bonds
  60. Anabolic steroids involves taking simple things like proteins and chaining them together via _____ bonds and forming _____ ____
    • peptide bonds
    • amino acids
  61. Heat death
    maximum entropy, when there is no longer usable energy available to do work in all the universe
  62. The universe is an ______ system & will always move toward ______
    • isolated
    • entropy
  63. Human beings are capable of taking energy and matter in making us ______ systems
  64. The body constantly couples ______ & ______ reactions to get things done. Cellular respiration would be an example of such a reaction
    endergonic & exergonic
  65. Cellular respiration begins with glucose and ends with _____. We get free energy from the______ of bonds. That free energy is used in different reactions for ex. putting a _____ on ADP to make ATP
    • CO2
    • breaking 
    • Phosphate
  66. The Na/K pump uses ______ reactions gains potential energy from the ______ _____. Potential energy can be used to chain _____ bonds.
    • exergonic 
    • concentration gradient
    • peptide bonds
  67. What binds to the active site of adenylyl cyclase?
    What does AC convert it into?
    • ATP
    • cAMP
  68. How would you make cAMP faster?
    make more adenylyl cyclase
  69. Reversible inhibition is inhibition of an enzyme without ______ the enzyme. If the inhibitor comes off, the ______ _____ of the enzyme returns to normal.
    • killing
    • reaction rate
  70. Competitive inhibition involves inhibitor binding to the _____ ____ and out-competing the natural ______. If the substrate can't bind, it can't _____ the reaction. This is a form of ______ ______.
    • active site 
    • substrate 
    • catalyze 
    • reversible inhibition
  71. Name two factors that determine whether a substrate or the competitive inhibitor binds at a certain site
    Concentration & affinity for the binding site
  72. If a substrate or inhibitor has a much higher _____ for a binding site, it can out-compete the other other. If _____ is evenly matched, the _____ levels will tip the scale.
    • affinity 
    • affinity 
    • concentration
  73. State an example of allosteric inhibition
    noncompetitive inhibition
  74. Noncompetitive inhibition involves the inhibitor not binding at the ____ ____ but at a ______ _____. When this occurs, it changes the _____ _____ of the enzyme, making it unfit for binding with the ______. The result: we are unable to _____ a reaction/ slowed reaction rate
    • active site 
    • different site
    • tertiary structure 
    • catalyze
  75. Allosteric activation: a molecule binds to a _______ _____ and ______ the activity of the enzyme
    • non-active site
    • amplifies
  76. Example of an irreversible inhibition
    nerve gas
  77. Nerve gas works by affecting an enzyme called __________ which is found at _______ synapses. These synapses are synapses that release ______ and are (the synapses) found in ______.
    • acetylcholinesterase 
    • cholinergic synapses
    • acetylcholine 
    • muscles
  78. *Acetylcholinesterase catalyzes a reaction that breaks ______ to an ______ & _______
    *=not tested
    • ACTH
    • acetate & choline
  79. The result of the reaction catalyzed by ACTHesterase is that _______ ceases to be a ________. Meaning?
    • ACTH 
    • neurotransmitter
    • It won't bind to receptors.
  80. What happens if ACTHesterase (enzyme) is disrupted?
    ACTH concentration goes up.
  81. How does nerve gas work? *=not tested (optional)
    • The enzyme has a pocket that acetylcholine goes to be broken/ it catalyzes a breakage of the bonds that hold ACTH together
    • Nerve gas will settle in that pocket and form covalent bonds rendering the enzyme useless. ACTH remains unbroken and begins to pile up.
    • The solution: make more acetylcholinesterase (takes time)
    • *Introduce atropine which will block muscarinic ACTH receptors. Diaphragm will continue to malfunction and muscles will continue to twitch but, this should keep the heart from stopping which will ultimately keep you alive.
Card Set
Energy enzymes & metabolism
Week 2 Pt 1 +audio breakdown