Bio 93 Discussion Week 5
REDOX Reaction for Cellular Respiration:
Label the 1) oxidizing and reducing agent and 2) what is being oxidized and what is being reduced.
Stage
Location
In
Out
Notes
Glycolysis
Cytosol
Glucose
ATP
Pyruvate
NADH
H2O
(ATP)
Energy input and energy payoff
stages
6 Carbon molecule  3 carbon
Intermediate
Mitochondrial
Matrix
Pyruvate
Acetyl CoA
CO2
NADH
CO2 = By-product
3 Carbon molecule  2 carbon
Citric acid cycle
Mitochondrial
Matrix
Acetyl CoA
CO2
NADH
FADH2
ATP
CO2 = By-product
FADH2 ~ NADH
Oxidative
phosphorylation
Inner
Mitochondrial
Membrane
NADH
FADH2
Lots of ATP!
Water
Fermentation
(No oxygen)
Cytoplasm
Pyruvate
Ethanol (yeast)
Lactic Acid
(mammals)
Most ATP generated by cellular
respiration comes from
oxidative phosphorylation
NADH and FADH2 from
glycolysis, Intermediate, and
citric acid cyle (Fig 9.16)
Recycles NADH to regenerate
NAD+ as long as there’s glucose
to burn to ultimately generate
ATP.
Electron transport chain
What is the force that drives ATP synthase to create ATP?
How is this force generated? Describe the proton
concentration gradient.
Proton motive force: Results from the gradient of H+
across the inner mitochondrial membrane. As H+ diffuses
down its concentration gradient (High H+ concentration in
the intermembrane space), it passes through ATP
synthase, driving the synthesis of ATP. This gradient was
formed using the energy from electron transport down
the chain.
REDOX Reaction for Photosynthesis:
Label the 1) oxidizing and reducing agent and 2) what is being oxidized and what is being reduced.
Stage
Light Reactions
Calvin Cycle
(Dark Reactions)
Location
In
Thylakoids
H2O
Light
(ATP + Pi and
NADP+ from
Calvin cycle)
Stroma
CO2
ATP
NADPH
RuBP
Out
Notes
NADPH
ATP
O2
Produces the chemical energy
and reducing power
G3P (3-carbon
sugar)
ADP + Pi
NADP+
RuBP
Uses ATP and NADPH to covert
CO2 to sugar (carbon fixation)
RuBP is used for the next Calvin
Cycle (3 cycles= 1 G3P)
The main output is G3P
Electron transport chain
How does the proton concentration gradient
drive ATP? How does this differ from cellular
respiration?
As H+ diffuses down its concentration gradient
(High H+ concentration in the thylakoid space;
low H+ concentration in the stroma), it passes
through ATP synthase, driving the synthesis of
ATP. This gradient was formed using the
energy from electron transport down the
chain.
In mitochondrion, protons diffuse down their
concentration gradient from the
intermembrane space through ATP synthase in the matrix, driving ATP synthesis. In chloroplasts, ATP is synthesized as
the hydrogen ions diffuse from the thylakoid space back to the stroma through ATP synthase. Thus ATP forms in the
stroma, where it is used to help drive sugar synthesis during the Calvin Cycle.