1. characteristics of ATP/ADP cycle
• The energy needed to make ADP to ATP (anabolic), it comes from catabolic
pathway (hydrolysis of ATP to ADP + Pi). Energy released from catabolic pathway is
used to drive anabolic pathway.
2. role of C-H bond in bioenergetics
• glucose is a good fuel molecules because of the abundance of hydrogen in the
form of C-H bonds. Electrons in C-H bond are farther away from the nucleus
contains more energy which can be easily removed.
• In contrast, molecules that have an abundance of O2 contain less Potential Energy
because O2 is high in EN. High EN, greater force that holds the e- to the atom,
thus, needs more energy to remove e-.
3. role of redox potential in bioenergetics
• Cellular respiration, for instance, is the oxidation of glucose (C6H12O6) to CO2
and the reduction of oxygen to water.
C6H12O6 + 6 O2 → 6 CO2 + 6 H2O
• The process of cell respiration also depends heavily on the reduction of NAD+ to
NADH and the reverse reaction (the oxidation of NADH to NAD+).
• Biological energy is frequently stored and released by means of redox reactions.
4. role of FAD, NAD+ as electron carriers
• note: NAD+ becomes reduced (add an H + 2 e-) to NADH - respiration
NADP+ becomes reduced (add an H) to NADPH – photosynthesis
◦ Therefore, you can think of NAD+ and NADP+ as energy "carriers" that shuttle
energy from one set of reactions to another (in the form of the bond with
• NAD+ is reduced to NADH + H+. in glycolysis and Krebs and feeds into the ETC at
Complex I and gives
3 ATP per NADH.
• FAD+ is reduced to FADH2 in Krebs Cycle and feeds into the ETC, lower down than
NADH, at Complex II and gives 2 ATP per FADH2.
6. role of energy coupling in early steps of glycolysis
• ATP+ glucose -> ADP + Glucose-6-P
• endergonic+exergonic energy are the energy coupling.
This is necessary to get negative delta G which is a spontaneous rxn.
7. relative potential energy of various intermediate compounds (eg. glucose vs. pyruvate
• glucose has a lot of energy
• some of the energy is used in glycolysis to reduce NADH, thus 2 pyruvates only get
the remaining energy
• CO2 has no usable energy, not charged as well.
8. reasons why catabolic intermediates are phosphorylated
• phosphates are charged
• glucose becomes more reactive 5. location, products, distribution in nature and purpose of pathways such as glycolysis,
CA cycle, respiratory electron transport etc.
Glycolysis Pyruvate Oxidation Kreb Cycle ETC
Locati Cytosol Mitochondria Mitochondria matrix Innermembrane
Produc 2 pyruvates- < 2 Acetyl CoA 2 CoA ATP
t free E 2 NADH+H 2 ATP
2 ATP 2 CO2 6 NADH+H
2 NADH+H 2 FADH2
Purpos Breakdown of Removing carboxyl Acetyl Co-A (2C) + To pass electrons
e glucose (6C) to 2 group from Oxaloacetate (4C) along the electron
pyruvates (3C) pyruvate and -> Citrate (6C) – transport until they
release CO2. Then 2 CO2 (lost 2 C) = get donated to O2,
react w coenzyme A 4C which is producing water.
to make a more 2oxaloacetate
bond Acetyl CoA
Notes ATP is Under anaerobic 2 cycles b/c of 2 The purpose of ATP
synthesized, conditions, acetyl CoA synthase is:
NADH is pyruvates are
synthesized converted into
No O2 involved. Dehydrogenase Pump H+ into
most ancient makes NADH intermembrane to
consume 2ATP at create
1 step to make concentration and
molecules more voltage gradient
reactive, then and drive proton-
pay them back motive force to
by producing 4 power oxidative
ATP phosphotylation to
9. link between glycolysis and Citric Acid Cycle
• the link is pyruvate oxidation
• the end product of glycolysis is 2 pyruvates.
• Each pyruvate has a carboxyl group- little potential energy because of no C-H bond
and a lot of O2). This group gets removed and CO2 is released
• NAD+ + 2 e- + H -> NADH in the presence of an enzyme dehydrogenase.
• Coenzyme A is attached to the remaining acetyl group forming HIGH ENERGY
INTERMEDIATE acetyl CoA
• If you look at the molecule of acetyl CoA, it contains 3 C-H bonds which can further
oxidized to release even more free Energy.
• Acetyle Co-A goes to kreb cycle. 10. role of pyruvate dehydrogenase complex
• to produce acetyl CoA, NADH and CO2
12. relative location of electron transport chain components r