Chapter 8 Cellular Respiration
Read Chapter 8 in Textbook
Read pages in Cliffs Book on cell
respiration (pg 71-76)
Mills AP Bio 2012
Chapter 8 Cellular Respiration
• Next test
– Ch 6-7-8
– Date: Mon Oct 10th ?
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Chapter 8 Cellular Respiration
• Topics
–
–
–
–
–
8.1
8.2
8.3
8.4
8.5
Cellular Respiration
Glycolysis
Fermentation
Inside the Mitochondria -Kreb’s Cycle and ETS
Metabolic Pool
Mills AP Bio 2012
Chapter 8 Cellular Respiration
8.1 Cellular Respiration
• Living things need energy to live
– Release energy from chemical bonds in foods
they eat
– Process called
cellular respiration
• Occurs in both plants and animals
– Problem:
• How do we eat food, and make it into something a
transitional cell in the bladder can use to carry on its
daily activities?
Mills AP Bio 2012
Chapter 8 Cellular Respiration
8.1 Cellular Respiration
Eat food
• Break down chemical bonds to:
– Create new chemical bonds –
store energy
– Create heat – body heat – can’t
use to do work
• Energy release must happen in
small steps
• Combination of all these steps =
cell respiration
Oxidation
Reduction
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What is being oxidized?
Reduced?
Chapter 8 Cellular Respiration
8.1 Cellular Respiration
• Cell respiration
– Involves many sequential steps, each catalyzed by its
own enzyme
– Begins with a metabolite, most commonly glucose
and ends with ATP
• Steps of cell respiration (using glucose)
–
–
–
–
1. Glycolysis
2. Transition reaction
3. Kreb’s Cycle
4. ETS
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Chapter 8 Cellular Respiration
8.1 Cellular Respiration
• Cell respiration steps - Overview
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Cell Respiration Overview
NADH
e–
NADH
e–
e–
e–
Cytoplasm
e–
NADH and
FADH2
e–
Glycolysis
glucose
pyruvate
Mitochondrion
e–
Citric acid
cycle
Preparatory reaction
Electron transport
chain and
chemiosmosis
2 ATP
2 ATP
4 ADP
4 ATP total
2
ATP
net gain
2 ADP
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2
ATP
32 ADP
or 34
32
or 34
ATP
Because you asked for it……
Totally Unrelated Trivia
• What is the name of the little lump of flesh just forward of
your ear canal, right next to your temple?
Tragus
• At what age does a human fetus acquire fingerprints?
Three months
21 week old fetus undergoing surgery for spina bifida.
Mills AP Bio 2012
Chapter 8 Cellular Respiration
End result of GLYCOLYSIS of
one glucose molecule:
8.2 Outside the Mitochondria - Glycolysis
•
2 pyruvic acid molecules
4 Step
hydrogen
(2 pair) atoms formed
1 Glycolysis
picked up by 2NAD+  2NADH + (2H+)  ETS
– First step in respiration
2 ATP used
– Occurs
4 ATP
formed in cytoplasm
– Doesn’t require oxygen
(anaerobic) can occur
with or without.
– Splits glucose into two
pyruvic acid molecules
– Net gain of 2 ATP and
2NADH (+2H+)
(PGAL)
(PGA)
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Glycolysis
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Glycolysis
Energy-investment Step
G3P
glyceraldehyde-3-phosphate
BPG
1,3-bisphosphoglycerate
3PG
3-phosphoglycerate
glucose
Glycolysis
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Glycolysis
Energy-investment Step
glucose
ATP
ADP
ATP
ADP
G3P
glyceraldehyde-3-phosphate
BPG
1,3-bisphosphoglycerate
3PG
3-phosphoglycerate
Glycolysis
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Glycolysis
Energy-investment Step
G3P
glyceraldehyde-3-phosphate
BPG
1,3-bisphosphoglycerate
3PG
3-phosphoglycerate
glucose
–2
ATP
ATP
ADP
ATP
ADP
Two ATP are used to get started.
Glycolysis
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Glycolysis
Energy-investment Step
glucose
–2
ATP
ATP
ADP
ATP
G3P
glyceraldehyde-3-phosphate
BPG
1,3-bisphosphoglycerate
3PG
3-phosphoglycerate
ADP
Two ATP are used to get started.
Splitting produces two
3-carbon molecules.
G3P
G3P
Glycolysis
Glycolysis
Energy-investment Step
glucose
–2
ATP
ATP
ATP
ADP
G3P
glyceraldehyde-3-phosphate
BPG
1,3-bisphosphoglycerate
3PG
3-phosphoglycerate
ADP
Two ATP are used to get started.
Splitting produces two
3-carbon molecules.
G3P
Energy-harvesting Steps
NAD+
G3P
NAD+
E1
NADH
NADH
BPG
BPG
Oxidation of G3P occurs as
NAD+ receives high-energy
electrons.
Glycolysis
Glycolysis
Energy-investment Step
G3P
glyceraldehyde-3-phosphate
BPG
1,3-bisphosphoglycerate
3PG
3-phosphoglycerate
glucose
–2
ATP
ATP
ATP
ADP
ADP
Two ATP are used to get started.
Splitting produces two
3-carbon molecules.
G3P
Energy-harvesting Steps
NAD+
G3P
NAD+
E1
NADH
NADH
BPG
A DP
Oxidation of G3P occurs as
NAD+ receives high-energy
electrons.
BPG
ADP
E2
Substrate-level ATP synthesis.
+2
ATP
ATP
ATP
3PG
3PG
Glycolysis
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Glycolysis
Energy-investment Step
glucose
–2
ATP
ATP
ATP
ADP
G3P
glyceraldehyde-3-phosphate
BPG
1,3-bisphosphoglycerate
3PG
3-phosphoglycerate
ADP
Two ATP are used to get started.
Splitting produces two
3-carbon molecules.
G3P
NAD+
G3P
NAD+
E1
Energy-harvesting Steps
NADH
NADH
BPG
ADP
Oxidation of G3P occurs as
NAD+ receives high-energy
electrons.
BPG
ADP
E2
Substrate-level ATP synthesis.
+2
ATP
ATP
ATP
3PG
3PG
E3
H2O
H2 O
PEP
PEP
Oxidation of 3PG occurs by
removal of water.
Glycolysis
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
End result of GLYCOLYSIS of
one glucose molecule:
Glycolysis
Energy-investment Step
glucose
–2
ATP
ATP
ATP
G3P
glyceraldehyde-3-phosphate
BPG
1,3-bisphosphoglycerate
3PG
3-phosphoglycerate
2 pyruvic acid molecules
4 hydrogen (2 pair) atoms formed
picked up by 2NAD+  2NADH + (2H+)  ETS
2 ATP used
4 ATP formed
ADP
ADP
Two ATP are used to get started.
Splitting produces two
3-carbon molecules.
G3P
Energy-harvesting Steps
NAD+
G3P
NAD+
E1
NADH
NADH
BPG
ADP
Oxidation of G3P occurs as
NAD+ receives high-energy
electrons.
BPG
ADP
E2
Substrate-level ATP synthesis.
+2
ATP
ATP
ATP
3PG
3PG
E3
H2 O
H2 O
PEP
ADP
+2
2
ATP
PEP
ADP
E4
ATP
ATP
(net gain)
Oxidation of 3PG occurs by
removal of water.
Substrate-level ATP synthesis.
ATP
pyruvate
pyruvate
Two molecules of pyruvate
are the end products of glycolysis.
Chapter 8 Cellular Respiration
End result of GLYCOLYSIS of
8.2molecule:
Outside the
one glucose
Mitochondria - Glycolysis
2 pyruvic
molecules
• Step
1 acid
Glycolysis
4 hydrogen (2 pair) atoms formed
– First step in respiration
picked up by 2NAD+  2NADH + (2H+)  ETS
Occurs
2–ATP
used in cytoplasm
4–ATP
formedrequire oxygen
Doesn’t
(anaerobic) can occur
with or without.
– Splits glucose into two
pyruvic acid molecules
– Net gain of 2 ATP and
2NADH (+2H+)
(PGAL)
(PGA)
Mills AP Bio 2012
Chapter 8 Cellular Respiration
8.3 Outside the Mitochondria - Fermentation
• In absence of oxygen
Fermentation Efficiency
– Glycolysis is only source of energy
– Pyruvic acid may be further 2 ATP x 7.3kcal each = 14.6 kcal
metabolized (reduced to lactate or
14.6/686
alcohol and CO2), but no more
energy = 2% which is < 39%
produced (only 2 ATP)
– This is called fermentation
– Used in wine and bread industries
among others
– Happens in our cells when energy
demands are high – especially in
muscles – leads to oxygen debt
Mills AP Bio 2012
Fermentation
glucose
–2
ATP
2
ATP
E1
2ADP
G3P
2NAD;
E2
2 NADH
BPG
4ADP
E3
+4
4
ATP
ATP
pyruvate
E4
or
2
ATP
2CO 2
(net gain)
2 lactate or 2 alcohol
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Animals
Plants
Chapter 8 Cellular Respiration
8.4 Inside the Mitochondria - Transition Reaction
• Step 2 Transition Reaction
(Preparatory Step)
– Connects glycolysis to Kreb’s
End Cycle
result of Transition Reaction
– Pyruvate  acetyl CoA, which
enters Krebs cycle
2 CO2 molecules
– Takes place in matrix of
4 H mitochondria
atoms (2 pair) 2NADH + 2H+  ETS
2 Acetyl CoA
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Chapter 8 Cellular Respiration
Mitochondria
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Chapter 8 Cellular Respiration
8.4 Inside the Mitochondria - Kreb’s Cycle
• Step 3 Kreb’s Cycle
– Series of reactions in a repeating
cycle, takes place in matrix of
mitochondria
– Does need oxygen (aerobic)
– Starts with acetyl CoA
– Each “turn” of the Krebs cycle
produces
• 1 molecule ATP
• 2 molecules of CO2
• 8 (4 pairs) of hydrogen atoms
(most of energy from glucose
carried here)
– Hydrogen atoms will later be
picked up by NAD+ and FAD
Mills AP Bio 2012
Chapter 8 Cellular Respiration
End result
of Kreb’s
Cycle:
8.4 Inside
the
Mitochondria - Kreb’s Cycle
• A closer look
4 CO2 molecules
16 H atoms (8 pairs) 6NADH + 6H+ + 2 FADH2
2 ATP
ATP used for enrgy to run
cell reactions.
x2
H eventually enters electron
transport chain,
used to produce ATP, then
combines with O2 to make
water.
CO2 dissolves in cytoplasm,
eventually carried away
in blood.
Mills AP Bio 2012
Chapter 8 Cellular Respiration
8.4 Inside the Mitochondria - ETS
• Step 4 Electron Transport System
–
–
–
–
Takes place in the cristae of mitochondria
Most of energy of cell respiration is produced here
Series of protein molecules in membrane
NADH + H+ and FADH2 deliver H+ and electrons to
system
– Ultimately ATP is formed
Mills AP Bio 2012
Chapter 8 Cellular Respiration
8.4 Inside the Mitochondria - Kreb’s Cycle
Because oxygen is the last hydrogen acceptor, and ADP has a
phosphate added, this process is called oxidative phosphorylation.
Occurs on membrane
of mitochondrial cristae
Hydrogen ions pumped from matrix to
intermembrane space of mitochondria
Hydrogen ions
pass back into
mitochondrial
matrix producing
ATP in the process
ELECTRON TRANSPORT CHAIN/SYSTEM (ETC/ETS)
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Chemiosmosis/simple H pump animation
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How is this ATP actually
produced?
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Chapter 8 Cellular Respiration
8.4 Inside the Mitochondria - Kreb’s Cycle
• Chemiosmosis
– Electrochemical gradient
of H ions used to
produce ATP
– Of the 36 molecules of
ATP produced from one
molecule of glucose
(being completely
metabolized), 32 come
from electron transport
system’s oxidative
phosphorylation.
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Mills AP Bio 2012
Chapter 8 Cellular Respiration
8.4 Inside the Mitochondria - Kreb’s Cycle
• Parkinson’s Disease
– The first time we spoke of the ETS, a student asked “what does this have
to do with anything?” Here’s an example.
• Problem with ETS proteins in mitochondria of certain dopamine producing brain
cells, leads to less ATP production. These cells then die. Less dopamine
produced.
• Dopamine is a neurotransmitter.
Mills AP Bio 2012
Chapter 8 Cellular Respiration
8.4 Inside the Mitochondria - Kreb’s Cycle
ATP Production/NADH/FADH/Chemiosmosis Animation
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Chapter 8 Cellular Respiration
8.4 Inside the Mitochondria - Kreb’s Cycle
• Cell Respiration – adding up the energy
Mills AP Bio 2012
Chapter 8 Cellular Respiration
8.4 Inside the Mitochondria - Kreb’s Cycle
• Cell Respiration – adding up the energy
32-34 ATP
produced by:
4 ATP produced
by:
Oxidative
phosphorilation
Substrate level
phosphorilation
Mills AP Bio 2012
36 ATP x 7.3kcal each = 263 kcal
Efficient
ourkcal
Cell
SoHow
263 kcal
of theis686
areMachinery?
held in the bonds of ATP
263/686 = 39% which is > 25%
• Facts:
Other
195 (686 – 263) kcal are lost from the cell as heat.
– The difference between the energy contained in the reactants
(glucose and oxygen), and the products (ATP, CO2 and H2O) is
+686 kcal (exergonic).
– Each ATP (high energy) bond holds about 7.3 kcal of energy.
– Car engine is about 25% efficient.
• Questions
– What is more efficient; a car or a cell?
– What happened to the rest of the energy?
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Chapter 8 Cellular Respiration
8.5 Metabolic Pool
• Anabolism
• Catabolism
• Metabolic pool
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• Read Connecting the Concepts to the Big Ideas pg 149
• Cell Resp Lab
– Ideal gas law
• http://www.chemistry.ohiostate.edu/betha/nealGasLaw/fr2.2.html
Mills AP Bio 2012
AP Lab #1 Osmosis/Diffusion
Percent Change in MassSucrose Molarity in Beaker
Contents in
Beaker
Percent
Change in
Mass
Graph 1.2 Percent Change in Mass of Potato Cores in Different Molarities of
Sucrose
Water
21.4
25
0.2M Sucrose
6.9
20
0.4M Sucrose
-4.5
15
0.6M Sucrose
-12.8
10
0.8M Sucrose
-23.0
1.0M Sucrose
-23.5
5
0
-5
-10
-15
-20
-25
0.0M
0.2 M
0.4M
0.6M
Sucrose Molarity in Beaker
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0.8M
1.0M
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