Transcript Slide 1

Feel the Burn
Do you like to run, bike, or swim? These all are good ways to exercise. When you
exercise, your body uses oxygen to get energy from glucose,
a six-carbon sugar.
1. How does your body feel at the start of exercise, such as a long, slow run?
2. How do you feel 1 minute into the run; 10 minutes into the run?
3. What do you think is happening in your cells to cause the changes
in how you feel?
4. Think about running as fast as you can for 100 meters. Could you
keep up this pace for a much longer distance? Explain your answer.
Marathon vs. dash?
Chapter 8
Cellular Energy
8.3 Cellular Respiration
Overview of Cellular Respiration
 Organisms obtain energy in a process called
cellular respiration.
 The equation for cellular respiration is the
opposite of the equation for photosynthesis.
Cellular respiration is the entire process of using oxygen to break
down glucose to release energy and form molecules of ATP. This
takes place in almost all organisms (including plants).
This takes place in the mitochondria in cells.
Glucose + Oxygen --->Carbon Dioxide + Water + Energy
Breakdown of Glucose (opposite to photosynthesis)
Overview of Energy breakdown:
• Glycolysis (no Oxygen)
Respiration (uses oxygen)
a. Kreb’s Cycle
b. Electron Transport
Goal = release energy from glucose
Why?
Chapter 8
Cellular Energy
8.3 Cellular Respiration
 Cellular respiration occurs in two main parts.
 Glycolysis
 Aerobic respiration
link
Section 9-1
Glucose
Figure 9–3 Glycolysis
2 Pyruvic acid
To the electron
transport chain
Chapter 8
Cellular Energy
8.3 Cellular Respiration
Glycolysis
 Glucose is broken down in the cytoplasm
through the process of glycolysis.
 Two molecules of ATP and two molecules
of NADH are formed for each molecule of
glucose that is broken down.
Figure 9–2
Section 9-1
Mitochondrion
Electrons carried in NADH
Pyruvic
acid
Glucose
Glycolysis
Krebs
Cycle
Electrons
carried in
NADH and
FADH2
Electron
Transport
Chain
Cytoplasm
Mitochondrion
Go to
Section:
Chapter 8
Cellular Energy
8.3 Cellular Respiration
Krebs Cycle
 Glycolysis has a net result of two ATP and
two pyruvate.
 The series of reactions in which pyruvate is
broken down into carbon dioxide is called the
Krebs cycle.
Summary :
reactants – Pyruvic acid
products – carbon dioxide, NADH, ATP, FADH2
(energy carriers)
Kreb’s Cycle –Overview- the first set of reactions in respiration.
Pyruvic acid is broken down producing carbon dioxide (given off),
NADH, ATP and FADH (electron carriers). Takes place in the
mitochondria.
Steps:
a. Pyruvic acid  Carbon dioxide given off
b. ATP, FADH2 and NADH are produced to carry energy to the next
step.
e. Cycle starts over again with remaining carbon compound.
Summary :
reactants – Pyruvic acid
products – carbon dioxide, NADH, ATP, FADH2 (energy carriers)
Chapter 8
Cellular Energy
8.3 Cellular Respiration
 The net yield from the
Krebs cycle is six CO2
molecules, two ATP,
eight NADH, and two
FADH2.
Chapter 8
Cellular Energy
8.3 Cellular Respiration
Electron Transport
Final step in the breakdown of
glucose
 More energy (ATP) is needed. NADH and
FADH2 are used to produce more ATP using
oxygen.
 Total of 36 ATP made during the three steps.
Summary:
Reactants: NADH, FADH2 (energy carriers), oxygen
Products: ATP (energy), Water
Section 9-2
Figure 9–7 Electron
Transport Chain
Electron Transport
Hydrogen Ion Movement
Channel
Mitochondrion
Intermembrane
Space
ATP synthase
Inner
Membrane
Matrix
ATP Production
•Summary of Cell Respiration :
Goal = release energy from glucose
Reactants (in)
Oxygen
Glucose
Products: (out)
Carbon Dioxide
Water
Energy ( ATP- net 36)
Aerobic - very efficient consumes oxygen to break down glucose, most
common form this form is used by animals.
the most energy (36 ATP) is released this way.
This is the way humans get energy for long term activities (over 90 secs).
After 15-20 minutesglycogen is used and fat burning begins.
38% efficient –36 molecules of ATP
Fact: Production of glucose by plants estimated at 91 billion tons per year.
Section 9-2
Flowchart
Cellular
Respiration
Glucose
(C6H1206)
+
Oxygen
(02)
Go to
Section:
Glycolysis
Krebs
Cycle
Electron
Transport
Chain
Carbon
Dioxide
(CO2)
+
Water
(H2O)
and Energy
Chapter 8
Cellular Energy
Anaerobic Respiration
 The anaerobic pathway that follows glycolysis
 Two main types
1. Lactic acid fermentation
2. Alcohol fermentation
Cellular
Respiration
Section 9-1
Figure 9–4 Lactic Acid
Fermentation
Glycolysis
Glucose
Go to
Section:
Pyruvic
acid
Lactic acid
How do you get energy if no oxygen is available?
Anaerobic (fermentation)-without oxygen not very efficient - doesn't provide
much energy (2 ATP).
Starts with Glycolysis and recycles NAD+ so Glycolysis can continue
ex. bacteria, yeast, some plants, some animals (people too!)
2 types of fermentation: (Both start with Glycolysis)
1. Lactic Acid FermentationPyruvic Acid + NADH Lactic acid + NAD+
This is how humans get energy in 90 seconds or less of strenuous activity. Lactic
acid is toxic, kills cells (ex. pitcher's arm)
Oxygen Debt- have to get rid of lactic acid
-Breath hard after strenuous exercise to get rid of CO2 and lactic acid.
2. Alcohol Fermentation (anaerobic) (bacteria and yeast)
Pyruvic Acid + NADH --> CO2 + Alcohol + NAD+
-carbon dioxide and alcohol are wastes
-alcohol fumes give bread its smell
-Net gain is 2 ATP from Glycolysis.
Products of fermentation cheese
yogurt
bread
Fermentation cont.
ex. activated yeast - feeds on sugar (must heat up to activate)
Produces Carbon Dioxide that causes air pockets in the bread, stops rising
when all carbohydrates are used up or enzymes are killed.
-Carbon Dioxide causes bubbles in beer.
-Tanks sealed to prevent air (oxygen).
If process becomes aerobic ---> no alcohol will be produced.
Wine and Vinegar also produced this way but with bacteria and yeast.
Big business all over the world.
History: Louis Pasteur studied fermentation to help the French wine
industry. He discovered “the Pasteur Effect” – When yeast and grape
juice are sealed into a fermentation vessel, the yeast grows until all the
oxygen is used up. At this point the yeast switches to fermentation and
alcohol is produced. The yeast uses up sugar very quickly during
fermentation since little energy can be released from each glucose
molecule without O2 (2ATP).
Chapter 8
Cellular Energy
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Chapter 8
Cellular Energy
Chapter Diagnostic
Questions
Which statement describes the law of
conservation of energy?
A. Energy cannot be converted or destroyed.
B. Energy can be converted and destroyed.
C. Energy can be converted but not destroyed.
D. Energy can be destroyed but not converted.
Chapter 8
Cellular Energy
Chapter Diagnostic
Questions
In which metabolic process are molecules
broken down to produce carbon dioxide and
water?
A. photosynthesis
B. cellular respiration
C. homeostasis
D. fermentation
Chapter 8
Cellular Energy
Chapter Diagnostic
Questions
At the end of the Calvin cycle, where is energy
stored?
A. NADPH
B. ATP
C. chloroplast
D. glucose
Chapter 8
Cellular Energy
8.1 Formative
Questions
Which law of thermodynamics explains
why the ladybug receives the least amount
of usable energy?
Chapter 8
Cellular Energy
8.1 Formative
Questions
A. the first law of thermodynamics
B. the second law of thermodynamics
Chapter 8
Cellular Energy
8.1 Formative
Questions
True or False
All of the energy from the food you eat
comes from the sun.
Chapter 8
Cellular Energy
8.1 Formative
Questions
Why is cellular respiration a catabolic pathway?
A. Energy is used to form glucose and
oxygen.
B. Energy is converted from water to
carbon dioxide.
C. Energy that is lost is converted to
thermal energy.
D. Energy is released by the breakdown
of molecules.
Chapter 8
Cellular Energy
8.1 Formative
Questions
Why is adenosine triphosphate (ATP) such an
important biological molecule?
A. It captures light energy from the sun.
B. It is produced in anabolic pathways.
C. It stores and releases chemical energy.
D. It converts mechanical energy to thermal
energy.
Chapter 8
Cellular Energy
8.2 Formative
Questions
Where in the plant cell does photosynthesis
take place?
A. chloroplasts
B. Golgi apparatus
C. mitochondria
D. vacuoles
Chapter 8
Cellular Energy
8.2 Formative
Questions
Which range of wavelengths is reflected by
chlorophylls a and b?
A. 400-500 nm
B. 500-600 nm
C. 600-700 nm
Chapter 8
Cellular Energy
8.2 Formative
Questions
Which mechanism of photosynthesis uses
the movement of hydrogen ions (H+) across
a concentration gradient to synthesize ATP?
A. absorption
B. chemiosmosis
C. electron transport
D. C2 pathway
Chapter 8
Cellular Energy
8.2 Formative
Questions
How are the C4 pathway and the CAM pathway
an adaptive strategy for some plants?
A. They accelerate photosynthesis.
B. They release more oxygen.
C. They help the plant conserve water.
D. They reduce the requirement for ATP.
Chapter 8
Cellular Energy
8.3 Formative
Questions
What is the overall purpose of cellular
respiration?
A. to make ATP
B. to process H2O
C. to store glucose
D. to deliver oxygen
Chapter 8
Cellular Energy
8.3 Formative
Questions
Which represents the general sequence of
cellular respiration?
A. TCA cycle
chemiosmosis
B. glycolysis
Krebs cycle
C. electron absorption
phosphorylation
D. aerobic pathway
fermentation
glycolysis
electron transport
catalysis
anaerobic pathway
Chapter 8
Cellular Energy
8.3 Formative
Questions
Which stage of cellular respiration is the
anaerobic process?
A. glycolysis
B. Krebs cycle
C. electron transport
Chapter 8
Cellular Energy
8.3 Formative
Questions
Which molecule generated by the Krebs
cycle is a waste product?
A. CoA
B. CO2
C. FADH2
D. NADH
Chapter 8
Cellular Energy
Chapter Assessment
Questions
Look at the following figure. Which part of the
chloroplast is a sac-like membrane arranged in
stacks?
A. grana
B. stroma
C. thylakoids
D. Golgi apparatus
Chapter 8
Cellular Energy
Chapter Assessment
Questions
During the Krebs cycle,
pyruvate is broken down
into what compound?
A. H2O
B. O2
C. CO
D. CO2
Chapter 8
Cellular Energy
Chapter Assessment
Questions
Look at the following figure. Which molecule is
released when ATP becomes ADP?
A. phosphate group
B. water molecule
C. ribose sugar
D. energy cells
Chapter 8
Cellular Energy
Standardized Test
Practice
Which metabolic process is photosynthesis?
A
B
Chapter 8
Cellular Energy
Standardized Test
Practice
At the beginning of photosynthesis, which
molecule is split to produce oxygen (O2) as
a waste product?
A. CO2
B. H2O
C. C6H12O6
D. 3-PGA
Chapter 8
Cellular Energy
Standardized Test
Practice
Which molecule helps provide the energy that
drives this cycle?
A. 3-PGA
B. CO2
C. NADPH
D. rubisco
Chapter 8
Cellular Energy
Standardized Test
Practice
Which product of the Calvin cycle is used for
the production of glucose and other organic
compounds?
A. ADP
B. CO2
C. G3P
D. NADP+
Chapter 8
Cellular Energy
Standardized Test
Practice
What is the final step of cellular respiration?
A. O2 and H+ form H2O.
B. Electrons and H2O generate ATP.
C. C6H12O6 is broken down into CO2.
D. NADH and FADH2 gain electrons.
Chapter 8
Cellular Energy
Standardized Test
Practice
What prevents pyruvate from entering the Krebs
cycle and instead results in this pathway?
A. a buildup of CO2
B. a lack of oxygen
C. an excess of
glucose
D. an increased
demand for ATP
Chapter 8
Cellular Energy
Standardized Test
Practice
Which is not a process that occurs in both
cellular respiration and glycolysis?
A. chemiosmosis
B. electron transport
C. glycolysis
D. production of G3P
Chapter 8
Cellular Energy
Glencoe Biology Transparencies
Chapter 8
Cellular Energy
Image Bank
Chapter 8
Cellular Energy
Vocabulary
Section 1
energy
thermodynamics
metabolism
Photosynthesis
cellular respiration
adenosine triphosphate (ATP)
Chapter 8
Cellular Energy
Vocabulary
Section 2
thylakoid
granum
stroma
pigment
NADP+
Calvin cycle
rubisco
Chapter 8
Cellular Energy
Vocabulary
Section 3
anaerobic process
aerobic respiration
aerobic process
glycolysis
Krebs cycle
fermentation
Chapter 8
Cellular Energy
Animation
 Visualizing Electron Transport