Chapter 9: Overview of Energy
Respiration vs Breathing
Photosynthesis: (Net Reaction)
Respiration:
(Net Reaction) AEROBIC CONDITIONS (O2 needed)
• In both reactions, there is a HYDROGEN and CARBON
pathway
a. Photosynthesis-- Joins the hydrogen and oxygen pathway
to form glucose
b. Respiration-- Separates these 2 pathways forming H2O
and CO2
Chapter 9: Cell Respiration
Notes
Aerobic Cell Respiration
• Complete oxidation of 1 glucose molecule
• Includes 4 major sets of reactions
NOTE: Parts 2, 3, 4 occur in mitochondria of
aerobic cells only
Part 4 occurs simultaneously with Parts
1, 2, 3 in aerobic cells
Aerobic Cell Respiration
• Review of Electron Carriers
a. NAD + 2H + 2e-  NADH + H+
b. FAD + 2H + 2e-  FADH2
Bring e- to ETC of inner mitochodrial membrane
Fermentation
• Aka Anaerobic
Respiration
• Catabolic process
that partially breaks
down sugars without
the use of oxygen
• Function of
fermentation is to
make ATP
Alcoholic Fermentation
PGAL
PGAL
Pyruvic
acid
Pyruvic
acid
Fermentation cont.
Fermentation Via:
Alcoholic Fermentation
Glycolysis followed by: pyruvic acid + NADH  2 alcohol + 2 CO2 + NAD+
Pyruvic Acids
(Alcohol)
Lactic Acid Fermentation
Glycolysis followed by: pyruvic acid + NADH  2 lactic acid + NAD+
Pyruvic Acids
(Lactic Acid)
Glycolysis
• Splitting of 1 glucose
molecule into 2
molecules of pyruvic
acid
• Can occur aerobically
or anaerobically
Glucose
PGAL
ATP made by process
called SUBSTRATELEVEL
PHOSPHORYLATION:
transfer of phosphate
group from a substrate
(reactant) molecule to
ADP ATP
Pyruvic Acid
Glycolysis
After Glycolysis
Respiration (4 Major Reactions)
1) Glycolysis (in cytoplasm)
•
•
Splitting of 1 molecule of glucose into 2 molecules
of pyruvic acid
Can occur in aerobic or anaerobic conditions
Glucose
PGAL
Pyruvic Acid
Respiration (4 Major Reactions) cont.
2) Pyruvic Acid Oxidation: Aerobic (in matrix)
The Oxidation of Pyruvate to form Acetyl CoA for Entry
Into the Krebs Cycle
Kreb’s
Cycle
Pyruvic Acid
Oxidation
Respiration (4 Major Reactions) cont.
3) Kreb’s Cycle/ Citric Aid Cycle (in matrix)
Kreb’s
Cycle
Pyruvic Acid
Oxidation
Citric Acid
Oxaloacetic Acid
Citric Acid Cycle (x2)
ETC
Respiration (4 Major Reactions) cont.
Oxidative Phosphorylation
High [H+]
Low pH
Low [H+]
High pH
Chapter 9: Methods of ATP
Synthesis Notes
3 Methods of ATP Synthesis
1) Photosynthetic Phosphorylation
• Process of making ATP (~P) with light energy
using electrons from hydrogen and chlorophyll
• Occurs during PSII
• On thylakoid membranes- in grana within
chloroplast
• Need enzyme (ATP synthetase & proton
pumps)- chemiosmosis
• Has ETC-- Electron Transport Chain-- PSII and
PSI
Photosynthetic Phosphorylation
4e4H+
4e-
4e-
Photosynthetic Phosphorylation
3 Methods of ATP Synthesis cont.
2) Substrate Phosphorylation
• Process of making ATP by rearrangement of
bonds of substrates during glycolysis or
Krebs Cycle (No energy added!)
a. Glycolysis (in cytoplasm)
o Occurs in aerobic and anaerobic
conditions
o No enzyme (ATP synthetase & proton
pump)
o No ETC-- no H2O made
a. Glycolysis (in cytoplasm) cont.
3 Methods of ATP Synthesis cont.
b. Krebs Cycle (in mitochondrion)
o Occurs only under aerobic conditions
o No enzyme (ATP synthetase & proton pump)
o No ETC-- no H2O made
3 Methods of ATP Synthesis cont.
3) Oxidative Phosphorylation
• Process of making ATP (~) from energy
released from hydrogen electrons (e-) as
they are carried to O2 by coenzymes via
the ETC or respiratory chain
• Occurs only under aerobic conditions
• Occurs only inside mitochondria (on
cristae membranes)
Oxidative Phosphorylation cont.
• Needs enzyme (ATP synthetase + proton pump + ATP
transport protein)
• Needs ETC or respiratory chain
• Final electron/ hydrogen acceptor is oxygen
• H2O is made
Oxidative Phosphorylation
Oxidative Phosphorylation
Conversions:
a. NADH (produced in the cytoplasm) produces 2 ATP by
the ETC
b. NADH (produced in the mitochondria) produces 3 ATP
by the ETC
c. FADH2 (adds its electrons to the ETC at a lower level
than NADH) so it produces 2 ATP
Net Energy Production from Aerobic Respiration
1. Glycolysis: 2 ATP
2. Krebs Cycle: 2 ATP
3. Electron Transport Phosphorylation: 32 ATP
a. Glycolysis: net gain/ 2 NADH (x 2) = 4 ATP
b. Pyruvate Acetyl CoA: 2 NADH (x 3) = 6 ATP
c. Krebs Cycle: 6 NADH (x 3) = 18 ATP
2 FADH2 (x 2) = 4 ATP
GRAND TOTAL: 36 ATP!!!