Bio 101 Test 5 Cellular respiration Chapter 8

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Bio 101Test 5 Cellular respirationChapter 8
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Intro to energy / metabolism next 4 slides

• Energy (E) is the ability to do work
• vs entropy
• vs equilibrium
• Life is competition
• think limited resources
• think economy
• goal more ATP from less resources
• So, how do organisms get energy from their
  surroundings?

Handouts?
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• Forms of energy in Biology
• 1. (covalent) bond energy e- energy like
  a rubber band
• a. glucose starch glycogen
  intermediates
• b. ATP main energy currency quick bond
  energy ADP PO4 ATP
• c. coenzyme transport bond energy bond
  middle-man made from B vitamins niacin
  riboflavin
• NAD H NADH FAD H FADH NADP H
  ? NADPH
• 2. Membrane potential (?P) charged Biological
  battery
• ion gradient across a membrane (ETM)
• 3. photochemical energy photons particles
  of light

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Intro. to energy continued

• 3 energy conserving metabolic processes in
  Biology
• 1. respiration (Test 5) 2. fermentation
  (Test 5) 3. photosynthesis
• Metabolism processes involved with energy
  transformation a. catabolism digestion
  breaking bonds exergonic ?S energy
  is released (so it can be captured)
• b. anabolism building forming bonds
  endergonic ?S energy is consumed
  (spent)
• remember the roller coaster?

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Oxidation-reduction reactions ie. redox

• Redox reactions transfer of electrons between
  reactants
• - - -
• - A - B - ? - A -
  - B -
• reductant oxidant oxidized
  reduced
• Reductant electron donor Oxidant electron
  acceptor
• LEO Loss of Electrons is Oxidation GER Gain
  of Electrons is Reduction
• NOTE reduce does NOT mean to get smaller
• Complete oxidation mineralization
• glucose ? CO2 (organic ? inorganic)
• Oxidized reduced form of coenzymes?

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• All organisms can be placed in 1 of 2 groups
• 1. primary producers autotrophs self-feeders
• inorganic carbon (CO2) ? organic carbon
  (glucose)
• a. photo(auto)trophs use light energy who
  are they?
• b. litho(auto)trophs use bond energy in
  inorganic reductants ex. sulfide
  H2S H2 NH3 others
• 2. secondary producers heterotrophs who are
  they?
• depend on autotrophs for organic carbon (O.C.)
• O.C. (food) ? O.C. (you)
• CO2 is our exhaust

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ATP

• ATP is adenosine tri-phosphate
• our main energy currency
• quick energy - immediate
• used where it is made
• ATP contains usable energy in a bond between
  phosphates. ATP ? ADP PO4- Energy

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3 ways to make ATP

• Photophosphorylation been there, done that
• Substrate level phosphorylation (SLP)
• simple 1 reaction NO redox no coenzymes
• involves transfer of PO4- from substrate to ADP
• S-PO4- ADP ? S ATP
• Oxidative level phosphorylation (OLP)
• complex, but worth it lots more ATP /
  glucose
• many reactions, breaking many bonds E release
  
• redox coenzymes involved
• Sacrificing membrane potential to make ATP

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3 energy conserving processesrevisited

• 1. Photosynthesis

• 2. Respiration
• 1. Uses SLP OLP
• 2. Must have a Terminal
• Electron
• Acceptor
• Mineralization
• Highly efficient
• Suffocation can occur
• Most organisms do this

• 3. Fermentation
• 1. Uses SLP ONLY
• 2. No TEA requirement
• Electrons balanced internally
• Incomplete catabolism
• Reduced by-products
• No suffocation
• Redox means nothing here
• Yeast, Streptococcus, etc.

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Aerobic heterotrophic respiration

• C6 H12 O6 6 O2 ? 6 CO2 6 H2O
  .. ATP
• glucose
• Glucose is the reductant, oxygen is the
  oxidant
• Mineralization!
• Are there other oxidants in respiration? Yes,
  but not for you!
• Its all about the ATP
• 3 parts a) glycolysis
• b) Krebs cycle
• c) ETS / OLP

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Glycolysis

• Glycolysis
• A reaction pathway NOT a cycle (circle)
• Where it happens
• Overall glucose ? 2 pyruvate (6 ? 2x3)
• 3 functions 1 pyruvate for Krebs
• NADH ATP (a little bit)
• 3 carbon intermediates
• See handout 2 phases investment profit
• NO CO2 no mineralization
• key intermediates, what happens where
• 3 classes of enzymes
• 1st part of respiration OR
  fermentation?
• yield, what goes where?

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Krebs cycle

• Cycle vs pathway
• 3 names Krebs citric acid
  tricarboxylic acid (TCA)
• Where it happens
• 3 functions 1 reduce coenzymes
• a little ATP (1 per pyruvate)
• 4-6 carbon intermediates
• See handout mineralization pyruvate ? 3 CO2
• intermediates, what happens where, etc.
• Glycolysis Krebs wrap-up totals
• electron tower

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ETS / OLP

• Where it happens
• What it is? Series of electron carriers
• Coenzymes oxidized here
• Chemical energy converted to membrane potential
• metabolism occurs here
• OLP occurs here ATP synthase
• Cytochrome oxidase
• superoxide dismutase 2 O-2 2 H ?
  H2O2
• catalase 2 H2O2
  ? 2 H2O O2
• Peter Mitchells Chemiosmotic theory