Big picture overview of cellular respiration

1. DO NOW
• Take out a piece of binder
paper & fold it into thirds
1.1. Top third – furthest placeTop third – furthest place
you’ve ever traveledyou’ve ever traveled
2.2. Middle third – middle nameMiddle third – middle name
3.3. Bottom third – last personBottom third – last person
you huggedyou hugged
Ankara, Turkey
RuthRuth
My momMy mom

2. An Overview of
Cellular
Respiration
Chapter 7
He’s getting
chemical
energy from
his food!

3. Big Diagram
Diagrams – 1 per team
• Phase 1: Glycolysis – glucose
enters cell and is broken in half to
make pyruvate
• Phase 2: Formation of Acetyl-CoA –
pyruvate enters mitochondria and
acetyl-CoA is formed
• Phase 3: Kreb’s Cycle (aka citric
acid cycle) – complete breakdown
of acetyl-CoA
• Phase 4: Electron Transport Chain –
the formation of a hydrogen ion
gradient
• Phase 5: Chemiosmosis – formation
of ATP
Include
• Everything!
• Be consistent with colors
with other teams
• Be consistent with size with
other teams

4. The Big Picture
• All cells require energy to do their work
• Cellular respiration produces this energy

5. What is cellular respiration?
• It is the main way that
chemical energy is
harvested from food
• Food molecules have
LOTS of energy – but that
energy can’t be used all
at once
• Food energy is stored as
ATP energy
Breathing
Cellular
respiration
Muscle
cells

6. Cellular respiration releases
energy
• Cellular respiration is catabolic and
exergonic
C6H12O6 + 6O2 --> 6CO2 + 6H2O + Energy (ATP and heat)
∆G = -686 kcal/mol of glucose broken down

7. • The energy released is stored in molecules of
ATP
• ATP is then used to power the cell
• Catabolic
reactions are not
directly used to
power the cell

8. Quick Think 1 – hug buddies
• Why don’t organisms use the
metabolic breakdown of food
directly to power the cell?
• In other words, why bother making
ATP?

9. General Information about
redox reactions
• Redox =
oxidation-
reduction
reactions
• Cellular respiration
is a series of redox
reactions

10. Many chemical reactions involve
the transfer of electrons from one
molecule to another
• These kinds of reactions
are called redox
reactions
• The loss of
electrons from a
substance =
oxidation
• The addition of
electrons to a
substance =
reduction

11. • The electron donor = reducing
agent (it reduced the other
substance)
• The electron acceptor = oxidizing
agent

12. Quick Think 2 – travel buddy
• In the following redox reaction, which
compound is oxidized and which is
reduced?
C4H6O5 + NAD+
 C4H4O5 + NADH + H+

13. Oxygen is a powerful
oxidizing agent
• Oxygen is very electronegative
• The more electronegative an atom is, the
more energy it takes to pull away its
electrons

14. When electrons
move from a less
electronegative
atom to a more
electronegative
atom, it releases
energy
• A reaction that puts electrons closer
to oxygen releases energy

15. Respiration - the oxidation of
glucose by oxygen
• During cellular respiration, hydrogen and
its bonding electrons change partners
• Hydrogen and its electrons go from sugar
to oxygen, forming water
Oxidation
[Glucose loses electrons (and hydrogens)]
Reduction
[Oxygen gains electrons (and hydrogens)]

16. The Overall Equation for Cellular Respiration
Oxidation:
Glucose loses electrons
(and hydrogens)
Glucose Carbon dioxide
Electrons
(and hydrogens) Energy
Oxygen
Reduction:
Oxygen gains
electrons (and
hydrogens)

17. • Why does transferring
electrons to oxygen
release energy?
When electrons
move from glucose
to oxygen, it is as
though they were
falling
This “fall” of
electrons releases
energy during
cellular respiration
Release
of heat
energy

18. Glucose is a good fuel
• It has a lot of hydrogens
• Makes it a reservoir of
electrons
• Those electrons want to go to
a lower energy state by
moving toward the more
electronegative oxygen

19. Quick Think 3 – middle buddy
• Redox reactions involve ___________.
• Oxygen is very __________ so it is a
good _________.
• In cellular respiration, oxygen is used
to _________ glucose, thereby
releasing __________ due to the fall
of ___________ from glucose to ____.

20. • Enzymes help glucose get
oxidized in a series of
controlled steps
• So that the energy being
released is released in a
controlled, useful way

21. Overall redox
summary of cellular
respiration
• Cellular respiration = electrons in
glucose --> NADH --> electron
transport chain --> oxygen

22. Big Diagram
Diagrams – 1 per team
• Phase 1: Glycolysis – glucose
enters cell and is broken in half to
make pyruvate
• Phase 2: Formation of Acetyl-CoA –
pyruvate enters mitochondria and
acetyl-CoA is formed
• Phase 3: Kreb’s Cycle (aka citric
acid cycle) – complete breakdown
of acetyl-CoA
• Phase 4: Electron Transport Chain –
the formation of a hydrogen ion
gradient
• Phase 5: Chemiosmosis – formation
of ATP
Include
• Everything!
• Be consistent with colors
with other teams
• Be consistent with size with
other teams