Transcript CH4.4-4.5 Cellular Respiration

Chapter 5
Section 3 Cellular Respiration
Objectives
• Summarize how glucose is broken down in the first
stage of cellular respiration.
• Describe how ATP is made in the second stage of
cellular respiration.
• Identify the role of fermentation in the second stage
of cellular respiration (next class)
• Evaluate the importance of oxygen in aerobic
respiration.
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New Vocabulary
•
•
•
•
•
•
•
Aerobic
Anaerobic
Glycolysis
Krebs Cycle
NADH
FADH2
Fermentation
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• What type of organic compounds are made during
photosynthesis?
Sugars (carbohydrates)
• Before organisms use the energy in organic
compounds, they must convert this energy to
ATP
cellular
_________
during the process of _______________
respiration
__________________
all
• Remember, ________
organisms respire…even
plants
expire
• If they don’t respire, they ____________
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Chapter 5
Section 3 Cellular Respiration
Oxygen
• __________________
in the air you breathe makes
the production of ATP more efficient, although some
without
ATP is made ______________
oxygen.
• Metabolic processes that require oxygen are called
aerobic
___________________.
• Metabolic processes that do not require oxygen are
anaerobic
called _______________,
which means “without air.
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Chapter 5
Section 3 Cellular Respiration
• In the process of
cellular respiration,
glucose
__________________
is broken down to
produce
energy
____________
within
a mitochondrion
__________________
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Structure of the mitochondrion
2 membranes
• _____
• Inner membrane is
folded
_________
• Space between the two
membranes is called
intermembrane
the ______________
space
• Space inside the inner
membrane is called the
mitochondrial
matrix
matrix
____________
Intermembrane space
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• The equation for cellular respiration is…
C6H12O6 + 6O2  6CO2 + 6H2O + ATP
Which reactant is needed for cellular respiration to be
efficient?
oxygen
In addition to energy, what other products are made?
Carbon dioxide, water
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Chapter 5
Section 3 Cellular Respiration
The Stages of Cellular Respiration
• Cellular respiration occurs in three main stages:
cytoplasm
Stage 1 Glycolysis: occurs in the ______________
mitochondrial
Stage 2 Krebs Cycle: occurs in the _____________
matrix
_________
Stage 3 Electron Transport Chain: occurs along the
folded __________
membrane
inner
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Chapter 5
Section 3 Cellular Respiration
Glycolysis
• Process in which ___________
glucose is
broken down into ____________
pyruvates
pyruvic
or _____________
acid
cytoplasm
• Occurs in the ______________
not need oxygen!
• Does _____
• 4 steps
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Chapter 5
Section 3 Cellular Respiration
Glycolysis: Step 1
2 ATP jumpstart
• _____
glycolysis
2 phosphates from ATP
• ____
glucose to form an
join __________
unstable 6-carbon
compound
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Chapter 5
Section 3 Cellular Respiration
Glycolysis: Step 2
• This unstable 6-carbon
compound immediately
2
breaks into ____
3-carbon compounds
PGAL
called ___________
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Chapter 5
Section 3 Cellular Respiration
Glycolysis: Step 3
• As glucose is broken
down some of its
hydrogen atoms join
___________
_________
to form
NAD+
NADH
__________,
which is an
energy storing molecule
• The hydrogen atoms are
replaced by two more
phosphate groups
__________
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Chapter 5
Section 3 Cellular Respiration
Glycolysis: Step 4
• The ____
4 phosphates bond
with 4 molecules of ADP to
make 4 _______
ATP molecules
• The remaining products are
two 3-carbon pyruvates,
which are ions of
pyruvic
acid
___________
________
• Remember that 2 ATP are needed to start the process,
2
so glycolysis produces a net gain of ______
ATP
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Chapter 5
Section 3 Cellular Respiration
Entering the Mitochondria
• The 3-carbon pyruvates are small enough to
___________
through the mitochondrial membranes,
diffuse
where they are each broken down into….
CO2
– One ________
acetyl
– One 2-carbon compound called an ___________
____________
group
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Chapter 5
Section 3 Cellular Respiration
• This process releases another hydrogen atom which
joins NAD+ to make one more molecule of
__________
NADH
• The acetyl group is attached to a molecule called
Coenzyme A (______)
CoA forming the compound
______________,
_________________
Acetyl-CoA
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• Each acetyl CoA enters the _________
Krebs cycle to start
stage 2 of cellular respiration
twice
– It turns __________,
once for each acetyl CoA
– This cycle is name after ___________________,
Hans Krebs
the scientist who discovered it
4 main steps
– Occurs in ____
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Chapter 5
Section 3 Cellular Respiration
Stage Two: Krebs Cycle (Step 1)
• Acetyl-CoA
enters the Krebs
cycle by joining
a 4-carbon
compound
called
oxaloacetic
_____________
_____________
acid
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Chapter 5
Section 3 Cellular Respiration
Stage Two: Krebs Cycle (Step 1)
• The new 6-carbon
compound is called
citric
_____________
___________
acid
• Since this is the
first product of the
Krebs cycle, it also
often called the
_____________
citric
acid
_________
cycle
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Chapter 5
Section 3 Cellular Respiration
Stage Two: Krebs Cycle (Step 2)
CO2 is released
• _____
from citric acid,
5
resulting in a ___
carbon compound
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Chapter 5
Section 3 Cellular Respiration
Stage Two: Krebs Cycle (Step 3)
CO2 is released
• _____
from the 5-carbon
compound, forming
a ____
4 carbon
compound
• So how many
molecules of CO2
are made during
the Krebs cycle?
2, but it turns
twice so 4
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Chapter 5
Section 3 Cellular Respiration
Stage Two: Krebs Cycle (Step 4)
• The 4-carbon
compound is
_____________,
rearranged
making
oxaloacetic acid
available for the
cycle again
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Chapter 5
Section 3 Cellular Respiration
• This cycle also
makes energy
storing
compounds…
– ____
3 NADH
– ____
1 ATP
– ____
1 FADH2
• Remember that the
cycle turns twice,
so it is really…
– ____
6 NADH
– ____
2 ATP
– ____
2 FADH2
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Chapter 5
Section 3 Cellular Respiration
Stage Three: Electron Transport Chain
• _________
NADH
and ________
FADH2 carry high energy
_________
electrons to the inner membrane of the
mitochondria, where they pass through an
electron
transport chain
______________
_____________
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Chapter 5
Section 3 Cellular Respiration
• The energy released from the moving electrons is
used to pump _____________
ions from
hydrogen
mitochondrial matrix to the _______________
intermembrane space
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Chapter 5
Section 3 Cellular Respiration
• This creates a build-up of hydrogen ions which will
_____________
through the ATP _____________
diffuse
synthetase
large
pump, producing __________
amounts of ATP
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Chapter 5
Section 3 Cellular Respiration
• As the diffusion of water is called osmosis, the
diffusion of chemicals, like H+, is called
chemiosmosis
___________________
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Chapter 5
Section 3 Cellular Respiration
• The last molecule in the electron transport chain to
O2
receive an electron is oxygen gas _______.
It binds
H2O
with hydrogen ions to make _________
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Chapter 5
Section 3 Cellular Respiration
• Without ___________,
oxygen
the electron transport chain
cannot pass along electrons and it easily gets
_________
blocked or clogged up
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Chapter 5
Section 3 Cellular Respiration
• This is why oxygen is so essential for most
organisms…without it the electron transport chain will
_____
stop working and _____
ATP will no longer be produced
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• The process of making large amounts of ATP in the
electron transport chain is called ______________
oxidative
______________________
phosphorylation
electrons are lost or
– Oxidation results when ___________
donated to other molecules
• Electrons are _________
passed from molecule to
molecule in the electron transport chain
phosphate
– Phosphorylation occurs when a ____________
group is added to a molecule
ADP
• Phosphates are added to _____
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• Summary of ATP made during cellular respiration
2 ATP
– Glycolysis
= ____
2 ATP
– Krebs Cycle
= ____
32 ATP to ___
34 ATP
– Electron Transport Chain = ____
– Total…
36 ATP to ___
38 ATP
= ____
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Question 1
•
What substance is broken down during cellular
respiration?
A. CO2 (carbon dioxide)
B. H2O (water)
C. O2 (oxygen)
D. C6H12O6 (glucose)
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Question 2
•
Why must glucose be converted to 2 pyruvates in
the cytoplasm, before these molecules cross
through the mitochondrial membranes?
Glucose is too big to diffuse across
the membranes
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Question 3
•
What is the first compound made during the Krebs
cycle?
A. Oxaloacetic acid
B. Citric acid
C. Acetyl CoA
D. pyruvate
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Question 4
•
Which energy storing compound is not made during
the Krebs cycle?
A. ATP
B. NADH
C. NADPH
D. FADH2
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Question 5
•
Which molecule is necessary to prevent the electron
transport chain from becoming clogged or backed
up?
A. CO2 (carbon dioxide)
B. H2O (water)
C. O2 (oxygen)
D. C6H12O6 (glucose)
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