Lets Review Glycolysis
and Fermentation
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Chapter 7
Photosynthesis-Cellular Respiration Cycle
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Chapter 7
Cellular Respiration Versus Fermentation
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Chapter 7
Section 1 Glycolysis and Fermentation
Two Types of
Fermentation
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After Glycolysis , When there IS
oxygen: Aerobic Respiration
occurs and NOT Fermentation!
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Chapter 7-2
I. Overview of Aerobic Respiration
A. In eukaryotic cells, aerobic respiration occurs in
the mitochondria In prokaryotes aerobic respiration
occurs in the cytosol
1. Pyruvic acid to ATP is the goal.
2. Aerobic produces 20 x more ATP than
glycolysis alone.
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Mitochondria Review
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Why do you think glucose has
to be broken down in
glycolysis to produce two
pyruvic acids BEFORE it
enters the mitochondria?
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B. The Krebs cycle occurs in the mitochondrial matrix
or the space inside of the inner membrane of the
matrix.
1. The e- transport chain (which is associated with
chemiosmosis) is located in the inner membrane.
2. When pyruvic acid enters the mitochondrial matrix
it reacts with coenzyme A and makes acetyl
conenzyme A (aka acetyl CoA).
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II. The Krebs Cycle
A. Acetyl CoA enters the Krebs cycle. Acetyl CoA is made of 2
Carbon Chain.
B. One glucose molecule is completely broken down in 2 turns
of the Krebs cycle and produces four CO2 molecules, two
ATP molecules, and hydrogen atoms that are used to make
six NADH and two FADH2 molecules.
C. The bulk of the energy released by the oxidation of glucose
still has not been transferred to ATP.
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Look at page 138.
Lets check out the
Kreb’s Cycle
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First Check out this stud!
Hans Kreb- German won the nobel prize in 1953 for the
discovery of this cycle!
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• He also discovered the urea cycle which switches
ammonia to urea in the animals!
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We need more ATP:
Random Fact: A human body uses
ATP at the rate of 1 million
molecules per cell per second.
There are 100 trillion cells in the
body. So that means that 1 x 10^20
ATP molecules are used each
second!
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III. e-Transport Chain
A. is the same in the thylakoid membrane as in
the mitochondria inner membrane
1. e- are donated from NADH and FADH2.
They are passed along losing energy until
they are received by an Oxygen
2. E- give off energy to pump protons
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B. Protons (hydrogen ions, H+) are also given
up by NADH and FADH2.
1. The high concentration of protons creates
a concentration gradient of protons and a
charge gradient across the inner membrane.
2. ATP is made as protons move through
ATPO synthase. Oxygen combines with the
electrons and protons to form water.
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Cyanide Poisoning
Cyanide binds irreversibly to the
last stop on the e- transport
chain causing the e- to back up
and the Cycle to shut down.
Once Kreb’s is stopped cells
use fermentation to create ATP
however it is not enough! Too
little ATP causes death of the
cells (especially brain cells).
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C. The Importance of Oxygen
1. ATP can be synthesized by chemiosmosis only if
e- continue to move along the electron transport
chain.
2. By accepting e- from the last molecule in the
electron transport chain, oxygen allows additional
electrons to pass along the chain.
3. As a result, ATP can continue to be made
through chemiosmosis.
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IV. Efficiency
• Cell respiration can produce up to 38 ATP from the
one glucose. Most eukaryotic cells produce 36 ATP
from 1 glucose.
• Thus, cellular respiration is nearly 20 times more
efficient than glycolysis alone.
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V.
Another Role of Cell Respiration
Molecules formed at different steps in glycolysis and the
Krebs cycle are used by cells to make compounds
that are missing in food.
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Chapter 7
Section 2 Aerobic Respiration
Summary of Cellular Respiration
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