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Cellular Respiration
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Athletes get the energy they need from the break down of glucose during cellular respiration.
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2. What types of cells does CR take place in?
Cellular respiration takes place in both ANIMAL and PLANT cells.
Animal Cells
Animal
Mitochondrion
Plant
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Plant Cells
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What organelle doe CR take place in?
The MITOCHONDRIA is where cellular respiration takes place.
Intermembrane space
Outer membrane
Inner membrane
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Mitochondrion
Matrix
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Key Facts about Cellular Respiration
1. Food is required.
2. The food is GLUCOSE (C6H12O6).
3. Glucose is broken down into ENERGY.
4. The energy made is in the form of ATP.
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The equation for cellular respiration is:
6O2 + C6H12O6 → 6CO2 + 6H2O + Energy
oxygen + glucose → carbon dioxide + water + energy
(ATP)
What are the reactants? ___________ and __________
What are the products? _________ and ________ and ____________
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6. Overview of Cellular Respiration
What is cellular respiration?
Cellular respiration is the process that releases energy by breaking down glucose and other food molecules in the presence of oxygen.
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Cellular Respiration has 3 parts:
Glycolysis
2.Kreb Cycle (Citric Acid Cycle)
3. Electron Transport Chain (ETC)
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8. Overview of Cellular Respiration
Electrons carried in NADH
Electrons carried
in NADH and
FADH2
Pyruvic acid
Glucose
Glycolysis
Cytoplasm
Cellular respiration is the process that releases energy by breaking down food molecules in the presence of oxygen. Glycolysis takes place in the cytoplasm. The Krebs cycle and electron transport take place inside the mitochondria.
Mitochondrion
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Anaerobic vs. Aerobic
ANAEROBIC - no oxygen required
GLYCOLYSIS, then FERMENTATION
AEROBIC - oxygen required
GLYCOLYSIS, then:
CITRIC ACID CYCLE
ELECTRON TRANSPORT CHAIN
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Glycolysis (part 1)
Where does it take place? cytoplasm of cell
(outside of mitochondria)
What is it? A series of chemical reactions that break down glucose
How? Breaks down glucose through chemical
reactions
Why? To make 2 molecules of pyruvic acid and 2
molecules of ATP
Does it require oxygen? NO – it’s anaerobic
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Glycolysis
ATP Production
At the beginning of glycolysis, the cell uses up 2 molecules of ATP to start the reaction.
2 ATP
2 ADP
4 ADP
4 ATP
Glycolysis is the first stage in cellular respiration. During glycolysis, glucose is broken down into 2 molecules of pyruvic acid.
Glucose
2 Pyruvic
acid
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Glycolysis
When glycolysis is complete, 4 ATP molecules have been produced.
2 ATP
2 ADP
4 ADP
4 ATP
Glucose
2 Pyruvic
acid
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Glycolysis
This gives the cell a net gain of 2 ATP molecules.
2 ATP
2 ADP
4 ADP
4 ATP
Glucose
2 Pyruvic
acid
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14. Kreb Cycle (Citric Acid Cycle) [Part 2]
Where does it take place? Mitochondria (inner matrix)
What is it? A series of chemical reactions that breaks down pyruvic acid
How? Pyruvic acid is changed into acetyl-CoA then
to Citric Acid -then to other carbon compounds
Why? Makes Carbon Dioxide and 2 ATP
Does it require oxygen? YES – it’s aerobic!
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15. The Krebs cycle begins when pyruvic acid produced by glycolysis enters the mitochondrion.
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Electron Transport Chain (ETC) [Part 3]
Where? Mitochondria (inner membrane)
What? Energized electrons move from protein to protein located in the
inner membrane of mitochondria
How? NADH and FADH2 give up electrons
Why? To make 32 ATP!!!
Does it require oxygen? YES – it’s aerobic!
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18. Electron Transport
High-energy electrons from NADH and FADH2 are passed along the electron transport chain from one carrier protein to the next.
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19. Electron Transport
As it rotates, the enzyme grabs a low-energy ADP, attaching a phosphate, forming high-energy ATP.
Channel
ATP synthase
ATP
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Fermentation
Fermentation
What happens when oxygen is not present?
Fermentation takes place after glycolysis.
NO KREBS CYCLE OR ETC!!!!
Fermentation releases energy from food molecules by producing ATP in the absence of oxygen.
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Fermentation
What are the two main types of fermentation?
Lactic Acid Fermentation
Alcoholic Fermentation
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23. (b) Lactic acid fermentation
Fig. 9-18b
2 ADP + 2 P
2 ATP i
Glucose
Glycolysis
2 NAD+
2 NADH
+ 2 H+
2 Pyruvate
Figure 9.18b Fermentation
2 Lactate
(b) Lactic acid fermentation

24. (a) Alcohol fermentation
Fig. 9-18a
2 ADP + 2 P
2 ATP i
Glucose
Glycolysis
2 Pyruvate
2 NAD+
2 NADH 2
CO2
+ 2 H+
Figure 9.18a Fermentation
2 Acetaldehyde
2 Ethanol
(a) Alcohol fermentation

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FERMENTATION
When? When cells are short on oxygen
What? Anaerobic process that follows glycolysis until oxygen is available.
How? Lactic Acid Fermentation or Alcoholic Fermentation
Why? To produce energy when oxygen is low
Requires Oxygen? No- it’s anaerobic!
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FERMENTATION
LACTIC ACID
Glucose
Pyruvic Acid
Lactic Acid + 2ATP
Occurs in bacteria, plants, and animals
Muscle fatigue
ALCOHOLIC
Glucose
Pyruvic Acid
Alcohol + 2ATP + CO2
Yeast
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27. Ethanol or lactate Citric acid cycle
Fig. 9-19
Glucose
Glycolysis
CYTOSOL
Pyruvate
O2 present:
Aerobic cellular
respiration
No O2 present:
Fermentation
MITOCHONDRION
Ethanol or
lactate
Acetyl CoA
Figure 9.19 Pyruvate as a key juncture in catabolism
Citric
acid
cycle

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9-1
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9-1
The raw materials required for cellular respiration are
carbon dioxide and oxygen.
glucose and water.
glucose and oxygen.
carbon dioxide and water.
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9-1
Glycolysis occurs in the
mitochondria.
cytoplasm.
nucleus.
chloroplasts.
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9-1
The net gain of ATP molecules after glycolysis is
3 ATP molecules.
2 ATP molecules.
3 pyruvic acid molecules.
4 pyruvic acid molecules.
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9-1
Fermentation releases energy from food molecules in the absence of
oxygen.
glucose.
NADH.
alcohol.
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9-1
The first step in fermentation is always
lactic acid production.
the Krebs cycle.
glycolysis.
alcohol production.
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