Download cellular respiration

CELLULAR RESPIRATION
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CHEMICAL ENERGY & FOOD
• One gram of glucose releases 3811 calories of
energy
 Calorie-amt of energy needed to raise the
temp. of 1g water 1°C
• Calories on food labels is
actually a kilocalorie
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• All activity burns calories
• If # calories is less than that burned then
the body consumes itself
• If # calories taken is more than burned
then they are stored in the form of fat
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What Is ATP?
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ATP = energy used by all Cells
• Adenosine Triphosphate
• organic molecule containing high-energy
Phosphate bonds
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Chemical Structure of ATP
Adenine Base
3 Phosphates
Ribose Sugar
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What Does ATP Do for You?
It supplies YOU with ENERGY!
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How Do We Get Energy From
ATP?
By breaking the
high- energy
bonds between
the last two
phosphates in
ATP
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CELLULAR RESPIRATION
• Cellular respiration- releases energy by
breaking down food/glucose in the
presence of O2
• 6O2 + C6H12O6 →6CO2 + 6H2O +
energy (ATP)
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Where Does Cellular
Respiration Take Place?
• It actually takes
place in two
parts of the cell:
Glycolysis occurs in
the Cytoplasm
Krebs Cycle & ETC
Take place in the
Mitochondria
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Review of Mitochondria
Structure
• Smooth outer
Membrane
• Folded inner
membrane
• Folds called Cristae
• Space inside cristae
called the Matrix
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Diagram of the Process
Occurs
across
Cristae
Occurs in
Cytoplasm
Occurs in
Matrix
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CELLULAR RESPIRATION – STAGES
1. glycolysis,
2. Kreb’s cycle,
3. electron transport chain (ETC)
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GLYCOLYSIS
• Doesn’t need O2
• Occurs in cytoplasm
• metabolic pathway found in all living
organisms
• What goes in? glucose
• What comes out? Pyruvic acid + 2 ATP
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Glycolysis- 1 glucose molecule is broken
in half, making 2 pyruvic acid
molecules
• Glycolysis releases energy, but also
needs energy (needs 2 ATP, makes 4)
• 4 high energy electrons are removed and
carried by NAD+ (NADP+ in psyth) to
other molecules
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• **BUT if too much ATP is made via
glycolysis then all the NAD+ get filled
quickly & so the process stops
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ANAEROBIC RESPIRATION
(w/o O2)
• If O2 is not present after glycolysis
then fermentation may occur
• Fermentation-releases energy from
food by making ATP w/o O2
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FERMENTATION:
alcohol & lactic acid
• Alcohol
 yeast & other microorganisms form
ethyl alcohol & CO2 from sugar
 Makes bread rise, makes wine, beer
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• Lactic acid
 in cells pyruvic acid is changed to
lactic acid
 Made in muscles during strenuous
exercise
 B/c the body can’t supply enough O2
to the tissues
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• Buildup of lactic acid hurts, this is
the cause of sore muscles after the
1st few minutes of exercise
• Some organisms also make lactic
acid as a waste product & are used
to make many foods & drinks like
cheese, yogurt, sour cream, etc…
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AEROBIC RESPIRATION
(w/O2)
• if O2 is present then glycolysis
enters the 2nd step of respiration;
 The Kreb’s cycle
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KREB’S CYCLE
• Needs O2
• Occurs in mitochondria
• What goes in? Pyruvic acid
• What comes out? 3CO2, 1ATP,
4NADH, & 1 FADH2
• CO2 is exhaled
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• ATP is used for cellular processes
• NADH & FADH2 is used to make
large amounts of ATP
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ELECTRON TRANSPORT CHAIN
(ETC)
• Where?- membrane of mitochondria
• What goes in? NADH, FADH2
• What comes out? ~34-36 ATP
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• High energy e-’s carried by
NADH & FADH2 from Kreb’s
cycle pump H+ ions across the
membrane
• The H+ power ATP synthase to
convert ADP to ATP
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• Totals
• 1 glucose = ~36 ATP
• Glycolysis=makes 4 uses 2 = 2;
in cytosol
• Kreb’s cycle + ETC = ~34
ATP; in mitochondria
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