Download ATP

Cellular Respiration
Harvesting Chemical Energy
ATP
Murdoch
Online upload 2014
2009-2010
Harvesting energy stored in food
• Cellular respiration
– breaking down food to produce ATP
• in mitochondria
food
• when using oxygen
–“aerobic” respiration
– usually digesting glucose
• but could be other sugars,
O2
fats, or proteins
ATP
glucose + oxygen  energy + carbon dioxide + water
C6H12O6 +
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6O2
 ATP + 6CO2 + 6H2O
What do we need to make energy?
• The “Powerhouse” for making energy
– mitochondria
• Fuel
– food: carbohydrates, fats, proteins
• Helpers
– oxygen
food
– enzymes
O2
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Make ATP!
Make ATP!
All I do all day…
And no one
even notices!
enzymes
ATP
CO2
H2O
What do we need to make energy?
• Product
– ATP
• Waste products
– carbon dioxide
• then used by plants
– water
• transpiration
Make ATP!
Make ATP!
All I do all day…
And no one
even notices!
food
enzymes
O2
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ATP
CO2
H2O
Mitochondria are everywhere!!
animal cells
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plant cells
Can’t store ATP
too unstable
only used in the cell
that produces each
ATP
ATP is only short
term energy
carbohydrates &
fats are long term
energy storage
Whoa!
Pass me the
glucose & oxygen!
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Using ATP to do work?
ATP
Adenosine TriPhosphate
Adenosine DiPhosphate
ADP
A working muscle recycles over
10 million ATPs per second
work
A Body’s Energy Budget
1
eat
food
make energy
ATP
2
synthesis
(building)
3
storage
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{
{
{
• energy
needed
even at rest
• activity
• temperature
control
• growth
• reproduction
• repair
• glycogen
(animal starch)
• fat
Cellular Respiration
• The first stage, glycolysis, is anaerobic—no oxygen is
required.
• The last two stages are aerobic and require oxygen to
be completed.
SUMMARY EQUATION:
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STAGES OF CELLULAR RESPIRATION
• Respiration occurs in three main stages
High-energy electrons
carried by NADH
GLYCOLYSIS
Cytoplasmic
fluid
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KREBS
CYCLE
ELECTRON
TRANSPORT CHAIN
Mitochondrion
Glycolysis
[Glyco=sweet, sugar; lysis = to split] ≡ a series of
chemical reactions in the cytoplasm of a cell that break
down glucose, a six-carbon compound, into two
molecules of pyruvic acid, a three-carbon compound.
4ATP
2ATP
2ADP
4ADP + 4P
Glucose
2 Pyruvic acid
2NAD+
2NADH + 2H+
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Glycolysis
Produces only two ATP molecules for each glucose
molecule broken down. (4 -2=2)
2 molecules of NADH are formed.
4ATP
2ATP
2ADP
4ADP + 4P
Glucose
2 Pyruvic acid
2NAD+
2NADH + 2H+
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Transition Phase
• Before citric acid cycle and electron transport chain
can begin, pyruvic acid undergoes a series of
reactions in which it gives off a molecule of CO2 and
combines with a molecule called coenzyme A to form
acetyl-CoA.
Acetyl CoA
(acetyl
coenzyme A)
acetyl-CoA
Pyruvic acid
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CO2
The citric acid cycle
(also called the Krebs cycle),
is a series of chemical
reactions in that the
molecule used in the first
reaction is also one of the
end products.
•
Occurs in mitochondrial
matrix
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CO2
The citric acid cycle
For every turn of the cycle,
one molecule of ATP and two
molecules of carbon dioxide,
3 NADH, 1 FADH2 are
produced.
Makes a total of 2 ATP, 6
NADH, & 2 FADH2
Occurs in mitochondrial
matrix
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CO2
The electron transport chain
• In the electron transport chain, the carrier molecules
NADH and FADH2 give up electrons that pass through
a series of reactions. Oxygen is the final electron
acceptor forming water.
• This sets up a H+ (proton) gradient.
• Occurs in the inner mitochondrial membrane
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The electron transport chain
• Allow the protons to flow through ATP synthase
which synthesizes ATP. (ADP + Pi = ATP)
• The electron transport chain adds 32 ATP molecules
to the four already produced during glycolysis & citric
acid cycle.
• Occurs in the inner mitochondrial membrane
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What if oxygen is missing?
• When no (or little) oxygen is available in
the environment = the cell can’t
complete aerobic respiration.
• Anaerobic respiration
– also known as fermentation
• alcohol fermentation
• lactic acid fermentation
– no oxygen or no mitochondria
(bacteria & Archaea)
– can only make very few ATP molecules
– large animals cannot survive
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O2
yeast
bacteria
Anaerobic Respiration
• Fermentation
– alcohol fermentation
• yeast
–glucose  ATP + CO2+ alcohol
–make beer, wine, bread
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Not enough
energy for me!
O2
Alcoholic fermentation
glucose pyruvic acid  2 ATP
GLYCOLYSIS
2 ethyl alcohol + 2 CO2
FERMENTATION
• used by yeast cells and some bacteria to produce CO2
and ethyl alcohol (EtOH).
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Anaerobic Respiration
• Fermentation
– lactic acid fermentation
• bacteria, animals
–glucose  ATP + lactic acid
–bacteria make yogurt
–animals feel muscle fatigue
–feel the “burn”
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Not enough
energy for me!
O2
Lactic acid fermentation
Glucose pyruvic acid  2 ATP
GLYCOLYSIS
2 lactic acid
FERMENTATION
• used to make cheese and yogurt
• during strenuous exercise not enough oxygen from
blood creates an “oxygen debt”
• lactic acid accumulates in muscle; leads to fatigue
and pain
• will be converted back to pyruvic acid in liver
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Compare & Contrast Photosynthesis
& Cellular Respiration
• Photosynthesis
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• Cellular Respiration
Got the energy…
Ask Questions!!
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