AP ? Of the Day
Write out the equation for cellular
respiration and then write out the following
correct identification of that reaction.
This process is…
A) Reduction and is endergonic
B) Reduction and is exergonic
C) Oxidation and is endergonic
D) Oxidation and is exergonic
Coming Up…

Quiz on Friday/Monday on Cell Respiration

Study lecture notes & Quizlet

Lab Tues/Wed

Friday we will take a quiz and you will
become Medical Examiners!
Today…
How many are done with POGILS?
 20 minutes to finish
 If you did finish, I will give you 5 pts.
Extra-Credit
 Take out your notes from first two reading
assignments. I will check you off.
 Lecture in 20 min
 Pre-lab questions
 Timer – 20 min

Cellular Respiration
and ATP too!
ATP
Adenosine TriPhosphate
 Stores small amounts of energy
 Nucleotide





Nitrogenous base - adenine
Sugar - ribose
Phosphate
Making ATP:


Substrate-level phosphorylation
Oxidative phosphorylation/Chemiosmosis
Cell Respiration Basics


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C6H12O6 + 6O2  6CO2 + 6H2O + ATP
Where: Mitochondria
Who: all organisms
Purpose: to make ATP
Aerobic


vs. Anaerobic
Needs O2
More ATP produced



No O2 needed
Little ATP made
Reduces NAD+ 
NADH
Glycolysis

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First step in Respiration
Aerobic & anaerobic
Glucose (6C)  2 pyruvic
acids (3C)
Use 2 ATP to split glucose
molecule
Create a total of 2 NADH
and 4 ATP while converting
to pyruvic acid
Net ATP produced = 2
Oxidation of Pyruvate



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
Oxidation – removing
electrons:
NAD+  NADH
Release CO2
Add Coenzyme A (CoA)
3C pyruvate loses a CO2 to
form a 2C acetyl CoA
This process happens 2x –
once for each pyruvate
formed in glycolysis
Review - Taboo
With a partner at a DIFFERENT table – one
person pick who they want to describe the
word, one person will guess the word.
 Person guessing, close your eyes.

Word: Oxidation
TABOO WORDS (YOU CANNOT SAY)
Electron
Loss
Reduction
Oxygen
Guesser is now the describer…
Word: Pyruvate
TABOO WORDS (YOU CANNOT SAY):
Glycolysis
Glucose
Break down
First-step
Kreb’s Cycle



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A 4C oxaloacetate binds to
the 2C acetyl CoA to form a
6C Citrate molecule
Oxidation of the citrate occurs
releasing CO2 and reducing
NAD+ to NADH
Oxidation occurs a second
time, an additional ATP is
made, and another CO2 is lost
We now have a 4C molecule
that needs to be returned to
oxaloacetate therefore it is
oxidized again (no CO2 is
released)
FAD  FADH2 &
NAD+  NADH
THE SIGNIFICANCE OF THIS
PROCESS IS THE CREATION
OF ELECTRON CARRIERS 
Kreb’s Cycle - Summary
Repeated cycle
 2 times for each glucose molecule
 2 ATP are produced for each glucose (1
per turn)
 6 NADH and 2 FADH2 are produced 
used in electron transport chain

Draw a picture…
Use the markers to draw the basics of the
Krebs cycle on your table.
 When I say switch, the person drawing
must pass the marker to the next person.

Electron Transport Chain
Electron Transport Chain

Occurs in the cristae membranes embedded with
cytochrome proteins.

Through a series of redox reactions, NADH and FADH2 give
up their high energy electrons to electron carriers in the
inner membrane (the cytochromes)

Oxygen is the final electron acceptor (highly
electronegative, pulls those electrons)

These energy releasing reactions (exerogonic) are used to
actively transport H+ out of the matrix into the
intermembrane space

This builds up a high concentration of H+
 NO ATP IS FORMED!
Oxidative Phosphorylation

What is being phosphorylated?

Why do we call it oxidative phosphorylation?

The oxidation of the carrier molecules NADH and FADH2
though the electron transport chain provide the energy
needed to create a proton gradient, that powers ATP
synthase

The H+ flow from high concentration to low concentration in
the matrix through the ATP synthase

The flow of H+ creates energy that is used to make ATP

The final electron acceptor in the e- t.c. is O2 which
combines with H+ and the e- to form H2O
What About Fats & Proteins?
Don’t they give us energy too?
Anaerobic Respiration
2 steps : glycolysis and fermentation
 2 types of fermentation: lactic acid and
alcohol
 Purpose: replace the NAD+ available for
glycolysis: NADH  NAD+

Lactic Acid
Fermentation
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


Alcohol
Fermentation
In both reactions pyruvic acid is reduced and NADH is oxidized to
become  NAD+
In alcohol fermentation CO2 is also released therefore alcohol (2C)
is produced instead of lactic acid (3C)
NAD+ returns to glycolysis so the process can continue and more
ATP can be made.
CO2 produced in alcohol fermentation is used to make bread rise
Pre-lab Write Up