Bell Work: What is this diagram
trying to tell us?
SUGAR
Cellular Respiration:
(Or, How to turn Glucose
into ATP)
Oxygen + Glucose => ATP + Carbon
Dioxide+ Water
Review: What is ATP?
• ATP stands for Adenosine
TriPhosphate.
•There is a large
• It looks like this:
amount of energy
between the bonds
of the last two
phosphates…..
A-P-P-P
How Cells Generate ATP
Cellular Respiration: The process of a
Cell making ATP (energy) using oxygen
and glucose.
• Involves 3 steps:
– Glycolysis
– Kreb’s Cycle (Citric Acid Cycle)
– Electron Transport Chain
Step 1 Glycolysis
• The first step of
cellular
respiration
takes place in
the Cytoplasm.
• The process of
breaking down
glucose (6 C’s)
into pyruvic
acid (3 C’s)
Spiral back review…. Facilitated
Diffusion is how the glucose gets
into your cells!
• Glucose is helped
across the membrane
by transport
proteins.
• Doesn’t require
energy
Energy Carriers
• Glucose contains lots of STORED energy.
• When glucose gets broken down, high
energy Hydrogen atoms (and their
electrons) are carried from Glycolysis to
the Kreb’s Cycle and Electron transport
chain for later use.
• These “energy carriers” are called
“NADH” and “FADH2”
Energy Carriers: NADH and
FADH2
Energy Cost
Glycolysis requires
some energy to get
started…..it costs the
cell 2 ATPs to get
started, but in the end
4 ATPs get made.
This gives a net gain
of 2 ATPs!!!
Now what do we do with those
Pyruvic Acids???
Recall: There are 3 main steps of
Cellular Respiration, so what was
step 2???
The Kreb’s Cycle! (Or Citric Acid Cycle)
But before the Kreb’s Cycle…
• There is a mini-step that takes the
Pyruvic Acid and turns it into a
compound called Acetyl Co-A.
• This enters the “Powerhouse” of
the Cell to kick off the Kreb’s
Cycle.
Mitochondria: label the matrix and cristae
Cristae
(Folded inner
membrane)
Matrix
(liquid)
Kreb’s Cycle
• Happens inside
the mitochondrial
Matrix.
• Turns twice to
process each
glucose molecule
• Results in 2 more
ATPs made!!!
1. Where is CO2
released?
(Circle in the
diagram)
2. How many
ATP’s are
released for 1
pyruvic acid?
(count!)
So…4 ATPs so far…where do the
rest come in?
Electron Transport Chain
• Last stage of Aerobic
Respiration
• Takes place on the Cristae
• High energy electrons go
between proteins.
Oxygen accepts the
electrons at the end and
combines with H+ to
make water.
32-34 ATPs made per glucose in the ETC.
Summary Picture
But what if the cells run low on
Oxygen???
Anaerobic Respiration
Fermentation
• When Cells don’t have enough oxygen for
Cellular Respiration (anaerobic)
• They do either Alcoholic or Lactic Acid as
a byproduct
• Only 2 ATPs are made…but that is better
than none!
Lactic Acid Fermentation
Alcoholic Fermentation
Dry Erase Review
Facilitators: Please grab a white
board for each student at your table.
Appoint someone else to fetch a
beaker of markers!
1. What is the name of the energy
molecule of all cells?
• ATP
2. What charge do the Posphate
groups have on the ATP
molecule?
• Negative
3. List the 3 steps of cellular
respiration.
• Glycolysis,
• Krebs Cycle
• Electron Transport Chain
4. What is the organelle that
converts glucose into ATP?
• Mitochondria
5. What are the 2 parts to a
mitochondria?
• Cristae, Matrix
6. Which part of the
mitochondria does the Kreb’s
cycle occur?
• Matrix
7. How many ATP are made in
Glycolysis?
• 4 total (but 2 are used up).
8. Which step of Cellular
Respiration releases Carbon
Dioxide?
• Kreb’s Cycle
9. What essential gas is the final
electron acceptor in the Electron
Transport Chain?
• Oxygen
10. What is the name of the
anaerobic process that cells fall
back on when oxygen runs low or
is unavailable?
• Fermentation
11. List the 2 types of
Fermentation.
• Lactic Acid and Alcoholic
12. Write the equation for
Cellular Respiration. **How is
this different than the
photosynthesis equation?
• Glucose + Oxygen  ATP + Carbon
Dioxide + Water
• This is nearly flipped from photosynthesis!
Individual Practice
Complete the Cellular Respiration
Overview worksheet. I will be
coming around to check on your
progress!