Download Ch 9 notes

Name:
Date:
Per:
Row:
Ch 9: Cellular Respiration
9-1 Chemical Pathways
A. Chemical Energy and Food
1. Food serves as a source of raw materials for the cells in
the body and as a source of energy.
2. Both plant and animal cells carry out the final stages of
cellular respiration in the mitochondria.
3. One gram of the sugar glucose (C6H12O6), when burned
in the presence of oxygen, releases 3811 calories of heat
energy.
4. Calorie- the amount of energy needed to raise the
temperature of 1 gram of water 1 degree Celsius.
5. Cells don't “burn” glucose. Instead, they gradually
release the energy from glucose and other food
compounds.
6. This process begins with a pathway called glycolysis.
7. Glycolysis releases a small amount of energy.
B. Overview of Cellular Respiration
Cellular respiration is the process that releases energy by
breaking down glucose and other food molecules in the
presence of oxygen.
1. The equation for cellular respiration is:
6O2 + C6H12O6 →
6CO2
+ 6 H2O + Energy
oxygen + glucose → carbon dioxide + water + Energy
Big Idea/Question/Notes:
Name:
Date:
Per:
Row:
2. Each of the three stages of cellular respiration captures
some of the chemical energy available in food molecules
and uses it to produce ATP.
Cellular Respiration Overview 
Use the words provided to label the diagram of cellular
respiration on the lines provided.
~ ATP, electron transport chain, glycolysis, Krebs cycle,
mitochondria
1. __________________________
2. __________________________
3. __________________________
4. __________________________
5. __________________________
Answer: 1. glycolysis; 2. ATP; 3. Krebs cycle; 4. mitochondria; 5. ETC
Big Idea/Question/Notes:
Name:
Date:
Per:
Row:
B. Glycolysis
1. Glycolysis takes place in the cytoplasm.
2. The Krebs cycle and electron transport take place in the
mitochondria.
3. Glycolysis is the process in which one molecule of
glucose is broken in half, producing two molecules of
pyruvic acid, a 3-carbon compound.
4. ATP Production
a. At the beginning of glycolysis, the cell uses up 2
molecules of ATP to start the reaction.
b. When glycolysis is complete, 4 ATP molecules have
been produced.
c. This gives the cell a net gain of 2 ATP molecules.
5. NADH Production
a. One reaction of glycolysis removes 4 high-energy
electrons, passing them to an electron carrier called
NAD+.
b. Each NAD+ accepts a pair of high-energy electrons
and becomes an NADH molecule.
c. The NADH molecule holds the electrons until they
can be transferred to other molecules.
6. The Advantages of Glycolysis
a. The process of glycolysis is so fast that cells can
produce thousands of ATP molecules in a few
milliseconds.
b. Glycolysis does not require oxygen.
Big Idea/Question/Notes:
Name:
Date:
Per:
Row:
C. Fermentation
1. When oxygen is not present, fermentation follows
glycolysis.
2. Fermentation releases energy from food molecules by
producing ATP in the absence of oxygen.
3. During fermentation, cells convert NADH back into the
electron carrier NAD+ that is needed for glycolysis.
4. This lets glycolysis continue to make a steady supply of
ATP.
5. Fermentation does not require oxygen—it is an anaerobic
process.
6. The two main types of fermentation are lactic acid
fermentation and alcoholic fermentation.
D. Alcoholic Fermentation
1. Yeasts and a few other microorganisms use alcoholic
fermentation
a. forming ethyl alcohol and carbon dioxide as wastes.
2. The equation for alcoholic fermentation after glycolysis
is:
pyruvic acid + NADH → alcohol + CO2 + NAD+
E. Lactic Acid Fermentation
1. Lactic acid fermentation occurs in muscles during rapid
exercise
2. Lactic acid fermentation converts glucose into lactic
acid.
Big Idea/Question/Notes:
Name:
Date:
Per:
Row:
3. The equation for lactic acid fermentation after glycolysis
is:
pyruvic acid + NADH → lactic acid + NAD+
Glycolysis and
Fermentation  
~ Follow the
prompts to identify
the important parts
of glycolysis and
fermentation
 Color the
carbon atoms
blue
 Circle the place
where ATP is
formed
 Mark and X on
the place where
ATP is used
Q: How many carbon
atoms are in one
molecule of glucose?
A: 6
Q: What is the product of glycolysis?
A: pyruvic acid
Big Idea/Question/Notes:
Name:
Date:
Per:
Row:
9-2 The Krebs Cycle and Electron Transport
A. Introduction
1. When oxygen is available, glycolysis is followed by the
Krebs cycle and the electron transport chain.
2. The three pathways together make up the process called
cellular respiration.
3. Because the pathways of cellular respiration require
oxygen they are aerobic.
B. The Krebs Cycle- Background
1. The Krebs cycle is the second stage of cellular
respiration
2. In eukaryotes, the Krebs cycle takes place in the
mitochondria
3. The Krebs cycle is also known as the citric acid cycle,
because citric acid is one of the first products
4. During the Krebs cycle, pyruvic acid is broken down into
carbon dioxide by a series of energy-extracting reactions
C. The Krebs Cycle- How it works!
1. The Krebs cycle begins when pyruvic acid produced by
glycolysis enters the mitochondrion.
2. One carbon molecule is removed, forming CO2, and
electrons are removed, changing NAD+ to NADH.
3. Coenzyme A joins the 2-carbon molecule, forming
acetyl-CoA.
4. Acetyl-CoA then adds the 2-carbon acetyl group to a 4carbon compound, forming citric acid.
Big Idea/Question/Notes:
Name:
Date:
Per:
Row:
5. Citric acid is broken down into a 5-carbon compound,
then into a 4-carbon compound.
6. Two more molecules of CO2 are released and electrons
join NAD+ and FAD, forming NADH and FADH2
7. In addition, one molecule of ATP is generated.
8. The energy tally from 1 molecule of pyruvic acid is
a. 4 NADH
b. 1 FADH2
c. 1 ATP
The Krebs Cycle  
~ Follow the prompts
to identify the important
parts of the Krebs cycle
 Color the carbon
atoms blue
 Circle the electron
carriers in green
 Circle ATP in
orange
Q: What does the cell
do with all those high-energy electrons in carriers like
NADH?
A:
Big Idea/Question/Notes:
Name:
Date:
Per:
Row:
D. Electron Transport
How are high-energy electrons used by the electron transport
chain?
The electron transport chain uses the high-energy electrons
from the Krebs cycle to convert ADP into ATP.
1. Electron transport is the third stage of cellular
respiration.
2. The electron transport chain uses the high-energy
electrons from the Krebs cycle to convert ADP to ATP.
3. In eukaryotes this process takes place in the inner
membrane of the mitochondria
4. In this pathway, high-energy electrons move from one
carrier protein to the next.
5. Their energy is used to move hydrogen ions across the
membrane through a protein called ATP synthase
6. Each time ATP synthase spins, a phosphate group is
added to an ADP molecule, producing an ATP molecule.
Big Idea/Question/Notes:
Name:
Date:
Per:
Row:
The Electron Transport
~ Label the diagram with the following terms: electron,
hydrogen ion, and inner membrane
Q: Where
in the
mitochond
rion does
the
electron
transport
chain take
place?
A:
Q: What happens to the high-energy electrons from the
Krebs cycle?
A:
7. In the absence of oxygen, all the energy that a cell can
extract from 1 glucose molecule is 2 ATP molecules (the
product of glycolysis)
8. In the presence of oxygen, the cell can extract many
more ATP molecules!
Big Idea/Question/Notes:
Name:
Date:
Per:
Row:
a. The Krebs cycle and the electron transport chain
enable the cell to produce 34 more ATP molecules
per glucose molecule!!!
**Complete the table using the words below. Some words
may be used more than once.
carbon dioxide
energy release
mitochondria
water
Photosynthesis
Cellular
Respiration
Energy capture
Function
Chloroplasts
Location
Glucose & oxygen
Reactants
Oxygen & glucose
Products
Answers:
Function- energy release
Location- mitochondria
Reactants- water and carbon dioxide
Products- carbon dioxide and water
E. Energy and Exercise
1. Human body cells normally contain small amounts of
ATP produced during cellular respiration
2. When the body needs energy in a hurry, muscle cells
produce ATP by lactic acid fermentation
Big Idea/Question/Notes:
Name:
Date:
Per:
Row:
3. On a global level, photosynthesis and cellular respiration
are also opposites
a. Photosynthesis removes CO2 from the atmosphere
and puts back O2
b. Cellular respiration removes O2 and puts back CO2
Big Idea/Question/Notes: