Download Cellular Respiration

Cellular Respiration
A
quick review…
 When
we eat, we get energy (glucose and
other sugars)
 Food
energy is broken down into usable
energy

Energy used to bond phosphate
groups to ADP to make ATP

ADP – P
ATP
Cellular Respiration
 What
is cell respiration???
 Respiration:
the process of breaking down
food molecules and changing these into
usable energy - ATP
 THE
GOAL:
Create ATP for cells to use
 Free up electrons—have high energy

Cellular Respiration
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Cellular Respiration
Cellular Respiration
 Types
of cell respiration
 Aerobic
Processes:
REQUIRE oxygen to take place
 A lot of energy available (efficient)

 Anaerobic
Processes:
DO NOT require oxygen to take place
 Get energy quickly (inefficient)

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Glycolysis
 Involves
 Break

breaking down 6-carbon sugars
sugars into pyruvic acid molecules
3-Carbon molecules
 This
 No
process is ANAEROBIC
oxygen necessary
 Occurs
in the cytoplasm of cells
Glycolysis
Glycolysis
 Glycolysis
also creates hydrogen ions
and free electrons

H +
The whole point of respiration = high energy
ions bond with NAD+ to form
NADH + H +

NADH carries electrons and H + ions
 This
process uses 4 ADP molecule and
creates 4 ATP molecules
Glycolysis
Glycolysis
 TOTAL
ATP PRODUCTION:
 Glycolysis
Step 1 uses 2 ATP molecules
 Glycolysis
Step 2 converts 4 ADP molecules
into 4 ATP molecules
 Net
ATP production = 2 ATP for every
glucose molecule
Glycolysis
 When
oxygen is present,
aerobic respiration occurs

Happens in the mitochondria
Glycolysis
 Breaking
down Pyruvic Acid…
 Occurs
in the mitochondria
 Pyruvic
Acid = 3-carbon compound
 Broken
down into…
2-Carbon compound—acetic acid
 Carbon Dioxide

Glycolysis
 Intermediate
 2-Carbon
Step in Glycolysis
Compound—Acetic Acid
Combined with coenzyme A (CoA)
 Forms compound called acetyl-CoA

 This
is only an intermediate step—have to
move pyruvic acid into Krebs Cycle
Glycolysis
Glycolysis =
2 ATP
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Citric Acid (Krebs) Cycle
 Produces
electrons
more ATP and releases more
 Electrons

picked up by NAD + and FAD
Organic carrier molecules
 Occurs
inside mitochondria
 Mitochondrial
Matrix
Citric Acid (Krebs) Cycle
 Acetyl
CoA combines with a 4-carbon
molecule to form a 6-carbon molecule

Citric Acid
 Citric
Acid broken down into a 5-carbon
compound
NAD + removes electrons (NADH + H +)
 CO2 released

Citric Acid (Krebs) Cycle
 5-carbon
compound broken down into a
4-carbon compound
ATP created
 NAD + removes electrons (NADH + H +)
 CO2 released

 4-carbon
created

compound (oxaloacetic acid) is
Used to bond with acetyl- CoA to restart cycle
Citric Acid (Krebs) Cycle
Citric Acid (Krebs) Cycle
Citric Acid Cycle =
2 ATP
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Electron Transport Chain
 What
is the ETC ?
A
series of molecules along which electrons
are transferred, releasing energy
 Occurs
in the mitochondria—
wall of mitochondria
 Aerobic

process
Oxygen is involved

Acts as the electron acceptor
Electron Transport Chain
 As
the electrons are passed between
carrier proteins, energy is released
 ATP
is created
 Electrons
molecules
 NADH
are given up by the carrier
and FADH2 ------- NAD + and FAD
Electron Transport Chain
Electron Transport Chain
 As
the electrons (H + ions) travel down
the chain, they bond with oxygen
2 H + + 1 O = water (H2O)
 Electron acceptor

 Carbon
is given off as carbon dioxide
Electron Transport Chain
Glycolysis
ETC =
34 ATP
Electron Transport Chain
A
problem exists if there is no oxygen

Anaerobic process
 When
oxygen is used up, electrons cannot
be removed

 KEY
Traffic jam in the mitochondria
POINT —Electron Transport Chain
cannot run without oxygen
Anaerobic Respiration
 If
no oxygen present after glycolysis,
pyruvic acid can still be broken down
 Fermentation
No ATP made during fermentation
 Uses
electrons carried by NADH + H +
so that NAD+ can regenerate for
glycolysis
Anaerobic Respiration
Anaerobic Respiration
 Two
types of fermentation
 Lactic
Acid Fermentation
Glucose
 Alcoholic
Glucose
2 Pyruvic
Acid
2 Lactic
Acid
Fermentation
2 Pyruvic
Acid
2 Ethanol
+ 2 CO2
Anaerobic Respiration
 Lactic
Acid Fermentation
 Muscle
fatigue
When your muscle cells require more energy
than can be produced
 Lack of oxygen
 Lactic acid build up = muscle fatigue


When oxygen is present, lactic acid breaks down
Anaerobic Respiration
Anaerobic Respiration
 Alcohol
Fermentation
 Occurs
in bacteria, plants and most animals
 Can
you think of a bacteria that is used for
fermentation???
 Pyruvic
Acid is converted into ethanol and
carbon dioxide
Anaerobic Respiration
Cellular Respiration
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Cellular Respiration
General Formula
C6H12O6 + 6 O2
6 CO2 + 6 H2O