Download A. glycolysis

Topic 05
Cellular Respiration
I. Energy for Life
A. ATP and ADP
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1. ATP-adenosine triphosphate – how energy
that is produced during cellular respiration is
packaged
2. ADP-adenosine diphosphate-formed when
one phosphate is removed from ATP-how
energy is released
ATP Molecule:
From ATP to ADP:
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B. oxidation-reduction reactions
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1.oxidation-any chemical change in which an
atom or molecule loses electrons
2. reduction-gaining electrons
3. oxidation-reduction reactions involve a
transfer of energy
4. OIL RIG – Oxidation Is Lose – Reduction Is
Gain
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C. Two types of phosphorylation
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1. oxidative phosphorylation – electrons are
transferred from electron donors to electron
acceptors such as oxygen – the energy released
from this process is used to turn ADP into ATP –
use of an electron transport chain (chemiosmosis)
2. substrate level phosphorylation – addition of a
phosphate group to ADP to make ATP – the
phosphate group is donated by another compound
II. Cellular Respiration
A video overview of cellular respiration
III. Aerobic respiration – respiration
with oxygen
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A. glycolysis- first step in cellular
respiration
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1. takes place in cytoplasm
2. must add 2 ATPs to start-get 4 out-net gain
of 2 ATPs
3. produce pyruvic acid (pyruvate) and 2
NADH (or NADH2)
Glycolysis
glycolysis
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A look at glycolysis
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B. Krebs cycle – second step in aerobic
respiration – also called the citric acid cycle
or the tricarboxylic acid cycle
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1. start with 2 Pyruvate (3 carbon compound)
2. becomes acetyl – CoA (2 carbon compound)
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3. acetyl – CoA changes shape and then joins
with a four carbon compound to make citric acid
(release a CO2 molecule)
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4. goes through a series of changes to produce 2
ATP, 6 NADH, 2 FADH2, and 4 CO2
5. the NADH and FADH2 go into the electron
transport chain
Final equation for the Krebs cycle:
Acetyl CoA + Oxaloacetate  citrate (citric acid)
 6 NADH + 2 FADH2 + 4 CO2 + 2 ATP
The Basics of the Krebs Cycle
The Krebs Cycle
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C. Electron transport chain
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1. All of the NADH and FADH2 produced
during glycolysis and the Krebs cycle are
delivered to the electron transport chain
2. the electron transport chain is responsible for
the majority of ATPs made during cellular
respiration
3. series of oxidation-reduction reactions
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4. the final electron (or hydrogen) acceptor at the
end is oxygen – the oxygen and hydrogen
combine to form water
5. As the electrons move from one acceptor to
another, their energy is used to pump protons
(H+) out of the mitochondrial interior which
creates a pH gradient across the inner
mitochondrial membrane
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6. A protein called ATP synthase found in the
inner mitochondrial membrane harvest the energy
of the pH gradient to produce the bulk of the ATP
from oxidative glucose metabolism
Biological Gradients - ATP Synthase
The Electron Transport chain
The Electron Trasnport Chain
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An indepth look at the electron transport chain
and oxidative phosphorylation.
IV. SUMMARY OF AEROBIC
RESPIRATION
NAME OF STEP
STARTING
MATERIALS
ENDING MATERIALS
1. Glycolysis
Glucose
2 ATP
4 ATP
2 NADH
2 pyruvate
2. Intermediate step
2 pyruvate
2 acetyl – CoA
2 NADH
3. Krebs Cycle (Citric Acid
Cycle)
2 acetyl-CoA
2 ATP
6 NADH
2 FADH2
4. Electron Transport Chain 10 NADH
(and Oxidative
2 FADH2
Phosphorylation)
34 ATP
V. Anaerobic respiration – without
oxygen
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A. glycolysis- first step in cellular
respiration
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1. takes place in cytoplasm
2. see handout
3. must add 2 ATPs to start-get 4 out-net gain
of 2 ATPs
4. produce pyruvic acid
B.fermentation-occurs after glycolysis-releases no
further energy – two types
(1) alcoholic fermentation – yeast cells – glycolysis
happens first and then the yeast cells convert
pyruvic acid into carbon dioxide and ethyl
alcohol
(2) lactic acid fermentation – human muscle cells –
glycolysis happens first and then the muscle cells
convert pyruvic acid into lactic acid
VI. Comparison of aerobic and anaerobic
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Anaerobic (without oxygen)
Two stages:
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1. glycolysis
2. fermentation
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Aerobic (with oxygen)
Three stages
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Must put in two ATPs to start –
get out four – net gain is 2
ATPs
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1. glycolysis
2. intermediate step
Krebs Cycle
3. electron transport chain
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Must put in two ATPs to start –
get out 38 – net gain is 36
ATPS
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Starts in cytoplasm
(glycolysis)and then goes into
the mitochondrion (Krebs cycle
and electron transport chain)
takes place in cytoplasm only