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ATP
ATP to Money Analogy
What if you want to pay for a parking meter?
Glucose
ATP
Where does the energy to
Organic Molecules!
make ATP come from?
Glucose
ATP
Where does the energy of ATP come from?
Breaking the bond holding the second &
third phosphate group releases energy!!
Energy
is
stored
Energy is
released
Draw along with me on the board
Draw in notebooks
Glycolysis
+
Station 1 - Glycolysis
Location (where does Reactants (starting
it occur?)
molecules)
Cytoplasm
Glucose
Products
2 Pyruvates
2 ATP
2 NADH
What does anaerobic mean?
• Does NOT require oxygen
What is the function of NADH? Where do they go?
• Deliver hydrogen ions (protons) & electrons to
the electron transport chain
+
Station 1 - Glycolysis
The process begins in the cytoplasm. Glucose first enters glycolysis. This
process in anaerobic, meaning that it does not require oxygen. A glucose
molecule has six carbon atoms. It is quite stable. This is, the bonds holding its
atoms together are not easily broken. Because of this stability, the cell must use a
small amount of energy to begin the glucose-splitting reactions. This is similar to
lighting a match to start a fire.
Glycolysis breaks down glucose into two molecules that each have three
carbon atoms. Enzymes rearrange the atoms in these molecules to form two
molecules of pyruvate. Glycolysis produces a small amount of ATP. Most of the
original glucose molecule’s energy, however, remains in the two pyruvate
molecules. Some prokaryotes and muscle cells with depleted oxygen supplies
only use glycolysis for energy needs. Many prokaryotes, as well as eukaryotes,
proceed to the next two stages of cellular respiration.
In addition to ATP, glycolysis produces two molecules of NADH. Some of
the energy from the glucose molecule transfers to these two molecules. Cells
sometimes use energy directly from NADH to do work. However, most of the
NADH is sent to the electron transport chain (the third stage of cellular
respiration), where it is converted to ATP.
Station 1 – Glycolysis Video
 https://www.youtube.com/watch?v=3GTjQTqUuOw
+
Station 1 - Summary & Key points
Breaks
down glucose into two
molecules of pyruvate
Anaerobic
oxygen!)
respiration (does not need
Products
2
pyruvate molecules
Net ATP = 2 ATP
2 NADH
+
Krebs
Cycle
Krebs
Cycle
+
Station 2 – Krebs Cycle
Location (where does Reactants (starting
it occur?)
molecules)
Products
Mitochondria
2 ATP
6 NADH
2 FADH2
4 CO2
2 Pyruvate
molecules
Where do the carbons from pyruvate get broken down into?
 CO2
which we exhale
The Krebs cycle is aerobic. This means….?
 It
requires oxygen
Where do the NADH and FADH2 go? What are they carrying?
 Electron
Transport chain carrying protons & electrons
Station 2 – Krebs Cycle
The pyruvate molecules now enter the second stage of cellular respiration,
the Krebs cycle. These reactions release most of the remaining energy in the
pyruvate. The reactions occur in the cell compartments called mitochondria.
Because the Krebs cycle requires oxygen, it’s called aerobic respiration.
During aerobic respiration, enzymes convert pyruvate into a 2 carbon molecule
by removing a carbon dioxide.
This 2-carbon molecule then enters the Krebs cycle. The Krebs cycle is a
stage of aerobic respiration that involves many enzymes and molecular
rearrangements. This cycle completes the release of energy from pyruvate by
breaking it down to carbon dioxide. This produces a little more ATP. It also
produces more hydrogen carrier molecules, including NADH. In humans, the
circulatory system transports to the lungs the carbon dioxide produced here and
in the conversion of pyruvate to the 2-carbon molecules. You exhale the gas as a
waste product.
Following the first two stages of cellular respiration, the energy from
glucose has been converted into energy in ATP molecules and hydrogen carriers
like NADH. NADH is an electron and hydrogen ion (H+) carrier. NADH is
transported to the third stage of cellular respiration, called the electron
transport system.
Station 2 – Krebs Cycle Video
https://www.youtube.com/watch?v=-cDFYXc9Wko
Station 2 - Summary & Key Points
 Two
Pyruvate molecules from glycolysis enter the krebs cycle
 Aerobic
respiration (requires oxygen!)
 The
krebs cycle must spin two times for every glucose
molecule
 NADH
& FAHD2 have the same function – both bring electrons
to the electron transport chain, where they are used to
produce more ATP.
 Carbon
from glucose is released as CO2, which we exhale.
 Products
2
ATP
 6 NADH
 2 FAHD2
 4 CO2
per glucose molecule(two spins):
Electron Transport Chain
Electron
Transport
Chain
Stage 3 – Electron Transport Chain
Location (where does Reactants (starting
it occur?)
molecules)
Products
Inner
membrane of
Mitochondria
32 ATP
6 H20
Electron
carriers
(NADH &
FADH2)
Why do protons diffuse across the membrane?
 Protons
diffuse from high concentrations (outside the inner membrane)
to low concentrations (inside the inner membrane)
Which enzyme produces ATP?
 ATP
Synthase
What molecule accept the electron at the end of the chain?
 Oxygen
https://blogmistry62.wordpress.com/2014/03/26/electron-transport-chain-etc/
Station 3 – Electron Transport Chain
The electron transport system consists of a series of electron carrier
molecules that are embedded in the inner membrane of the mitochondria. The
hydrogen atoms carried by NADH and FADH2 are separated into a hydrogen
ion (H+) and electron. The electrons are passed to a chain of electron carrier
molecules. As the electrons move from one carrier to the next, they release
energy. Some of this energy pumps the hydrogen ions (H+) across the inner
membrane of the mitochondrion. The H+ accumulate in the outer compartment
of the mitochondrion. The difference in concentration of H+ inside and outside
the inner compartment of the mitochondrion produces a concentration
gradient. The H+ tend to diffuse from the outer compartment, where they are in
high concentration, back across the membrane to the inner compartment, where
their concentration is lower.
To diffuse into the inner compartment, the H+ must pass through an
enzyme complex called ATP Synthase located in the membrane. The enzyme
complex works much like a water wheel that captures the potential energy of a
flowing stream to grind wheat. In this case, the flow of H+ through the enzyme
complex makes ATP from ADP and phosphate. In this way, the energy from
NADH is transferred to ATP. The transferred electrons then combine with H+
and molecular oxygen (O2) to form water (H2O). Overall, the electron
transport chain is where the energy stored in NADH & FADH2 is used to
produce large amounts of ATP.
Station 3 – Electron Transport Chain Video
 https://www.youtube.com/watch?v=kN5MtqAB_Yc
Station 3 - Summary & Key Points
 Hydrogen
ions & electrons from NADH & FADH2 are dropped off
in the electron transport chain that is located in the inner
membrane of the mitochondria.
 As
electrons pass through the electron transport chain, they
release energy, which is used to pump H+ ions across the
membrane.
 The
resulting H+ gradient causes H+ ions to diffuse back across
the inner membrane through ATP Synthase, which converts ADP
to ATP.
 Aerobic
respiration (requires oxygen!)
 Oxygen
is the final electron acceptor.
 Products:
 34
ATP
 Water
• What type of cells in the human body are
going to have a lot of mitochondria to do
cellular respiration?
Muscles!!!
Copyright © 2010 Ryan P. Murphy
Anaerobic Respiration
Occurs when there is no oxygen or
an insufficient amount of oxygen
for aerobic cellular respiration to
occur.
This form of metabolism uses a
reactant other than oxygen to
accept electrons in the electron
transport chain!
• How are these athletic events different? How
does each one breath?
• Aerobic and Anaerobic Respiration.
– What is the difference between the two?
– http://www.bbc.co.uk/schools/gcsebitesize/science/
add_ocr_gateway/living_growing/respirationact.sht
ml
• Aerobic Respiration: A form of cellular respiration
that requires oxygen in order to generate energy.
• Aerobic Respiration: A form of cellular respiration
that requires oxygen in order to generate energy.
• Anaerobic Respiration: A form of cellular
respiration that occurs when oxygen is absent or
scarce.
• In anaerobic respiration: Glucose isn’t completely
broken down..
• In anaerobic respiration: Glucose isn’t completely
broken down..
“Ahh, leg
cramps, It
hurts….”
• In anaerobic respiration: Glucose isn’t completely
broken down..
The waste product is
lactic acid rather than carbon
dioxide and water
“Ahh, leg
cramps, It
hurts….”
• In anaerobic respiration: Glucose isn’t completely
broken down..
The waste product is
lactic acid rather than carbon
dioxide and water
“Ahh, leg
cramps, It
hurts….”
Fermentation
Fermentation:
Anaerobic process
where energy is
produced from
glucose in the
absence of oxygen.
Alcohol
Fermentation
Lactic Acid
Fermentation
Alcohol Fermentation
→ Used by many bacteria and
yeast.
→ Pyruvate from glycolysis is
converted to ethanol.
→ CO2 is a byproduct of alcohol
fermentation.
Alcohol Fermentation
Process used to make bread,
beer, wine, and other spirits.
When yeast “burps” it releases
CO2 which causes bread to rise!
+
Alcohol fermentation
Lactic
Acid
Fermentation
Lactic Acid Fermentation
Occurs in some bacteria
and animal cells
• Specifically muscle tissue!!!
When cells do not receive
enough O2 they convert
pyruvate to lactic acid
When we exert
too much
energy our
muscles do not
receive enough
oxygen for
aerobic
respiration to
occur.
Lactic Acid
production
produces
energy but
results in
cramping!!!
OWW!!
Use bacteria and yeast to make cheese and yogurt
+
Lactic acid fermentation
Anaerobic
Fermentation
Alcoholic
Lactic Acid
Ex. Yeast,
wine
Ex. Yogurt,
tired muscles
Since there is no
Oxygen present,
ONLY glycolysis
occurs
Types of respiration
Aerobic
Requires
Oxygen
Glycolysis, Krebs
cycle,
and Electron transport
chain
Produces
Occurs
ATP
in mitochondria
Anaerobic
Does
not require
oxygen
Only
glycolysis
Produces
lactic acid &
ethanol
Produces
Occurs
ATP
in cytoplasm