Transcript ch9cellrespir

Chapter 9
Cellular
Respiration
•Feel the Burn
Section 9-1
Interest Grabber
•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? How do you feel 1 minute into the run; 10
minutes into the run?
2. What do you think is happening in your cells to
cause the changes
in how you feel?
3. 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.
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Section:
I. Chemical Pathways
***Food serves as a source of raw
materials for molecular synthesis
and energy
A. Chemical Energy and Food
–
•
1 g glucose when burned in the presence of O2
releases 3811 calories of heat energy.
– A _______________is the amount of energy
needed to raise the temperature of 1 g water 1
degree C.
The calorie used on food labels is a kilocalorie,or
1000 calories
calorie
– Cells don’t “burn” glucose.Instead,they gradually
release the energy from glucose and other food
compounds.
– Begins w/ __________________________-a
pathway that releases a small amount of energy .If
O2 is present,it turns to 2 other pathways that
release a lot of energy ---and if O2 is not
present,glycolysis is followed by another
pathway.
glycolysis
Section 9-1
Chemical Pathways
Glucose
Glycolysis
Krebs
cycle
Fermentation
(without oxygen)
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Section:
Electron
transport
Alcohol or
lactic acid
• Final steps of cellular respiration takes
place in the _________________
mitochondrion
Overview of Cellular Respiration
•
In the presence of O2,Glycolysis is followed by the
Krebs cycle and the electron transport chain .
– Glycolysis,electron transport chain and Kreb’s
cycle make up___________________-the process
that releases energy by breaking down glucose
and other food in the presence of O2
– CELL RESPIRATION
equation:_________________________
– Requires O2 ,food and gives off CO2 ,water and
energy
• The cell has to find a way to trap these little bits of
energy to make ATP
Make correction on
notes here !
6 O2+ C6H12O6- 6 CO2 + 6 H2O +energy
Cellular
respiration
Section 9-1
Electrons carried in NADH
Electrons
carried in
NADH and
FADH2
Pyruvic
acid
Glucose
Glycolysis
Mitochondrion
Krebs
Cycle
Electron
Transport
Chain
Cytoplasm
Mitochondrion
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Section:
• Glycolysis= process in which one molecule of
glucose is broken in ½ ,producing 2 molecules of
_________________,a 3-C compound
Pyruvic acid
Section 9-1
Figure 9–3 Glycolysis
Glucose
2 Pyruvic
acid
To the electron
transport chain
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Section:
Glycolysis Process
•
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1) ATP Production
2 molecules of _____ used @ beginning/4
molecules ATP are produced @ end-net
gain of 2 molecules
ATP
2- NADH Production
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4 high energy molecules are removed and passed onto
electron carrier _____________-nictotinamide adenine
dinucleotide-these accept a pair of high energy electrons
making ________________ and it passes
electrons onto next molecule.Energy is passed from glucose
to other pathways.
Process is fast so ATP is produced –a lot in a short amount
of time.
Does not require O2
A problem:when a lot of ATP is made from glycolysis-NAD+
fills w/electrons and w/o NAD+,glycolysis stops
Nad+
nadh
D. Fermentation
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Follows glycolysis if O2 is not present
_______________releases energy from food
molecules by making ATP in the Absence of O2.
Cells convert NADH to NAD+ by passing electrons
to _____________acid.This coverts NADH back to
carrier NAD+,allowing glycolysis to continue
Called__________because it does not require O2
Fermentation
anaerobic
Pyruvic
acid
Types of Fermentation
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1)
Alcoholic Fermentation
– Used by___________________
– Ethyl alcohol and CO2 are made as waste
Pyruvic acid + NADH-- alcohol + CO2 + NAD+
Causes bread dough to rise due to _____
Yeasts and other
microorganisms
CO2
2) Lactic Acid Fermentation
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Fermentation that uses pyruvic acid produced to
convert to lactic acid
Regenerates NAD+ so glycolysis can continue
Pyruvic acid + NADH-- lactic acid + NAD+
Produced in muscles during rapid exercise when the
body cannot supply enough ___ to the tissues.(for
ATP production)
Causes a painful burning sensation
Unicellular organisms also produce lactic acid as a
waste during fermentation…..eg .prokaryotes in
yogurt production,buttermilk,sauerkraut…
O2
Section 9-1
Glucose
Go to
Section:
Figure 9–4 Lactic
Acid Fermentation
Pyruvic acid
Lactic acid
Section 9-2
Interest Grabber
• Rolling and Folding
• Some of the steps in cellular respiration
take place in the membrane inside the cell
structure called the mitochondrion, which
has a folded inner membrane. What
purpose do these folds serve?
• To find out the answer to this question,
Go to
perform this activity.
Section:
Interest Grabber continued
Section 9-2
• 1. Obtain two sheets of paper and a metric ruler.
What is the surface area of the paper?
• 2. Roll one sheet of paper into a tube lengthwise.
What is the surface area of the rolled paper?
• 3. Fold the second sheet of paper into a fan. Then,
roll the first
sheet of paper around the folded paper so it is inside
the rolled paper.
What has happened to the surface area of the inside
of the rolled paper?
• 4. What would be the value of increasing the
surface area of the membrane inside a
mitochondrion?
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Section:
Section 9-2
Flowchart
Cellular Respiration
Glucose
(C6H1206)
+
Oxygen
(02)
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Section:
Glycolysis
Krebs
Cycle
Electron
Transport
Chain
Carbon
Dioxide
(CO2)
+
Water
(H2O)
A. The Kreb’s Cycle
–
–
CO2
During the Kreb’s Cycle,pyruvic acid is broken
down into ______ in a series of energyextracting steps
Because ________________is the 1st
compound formed,it is also called
___________________.
Citric acid
Citric acid
cycle
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1) Begins when pyruvic acid produced by
glycolysis enters the _________________.
– 1 C-atom pyruvic acid becomes part of
CO2 and gets released into the air.
2) Citric acid is broken down into a 4-C
molecule,more CO2 is released,and
_________________are transferred to
energy carriers
electrons
mitochondrion
• For each turn of the cycle,a molecule similar to
ADP is converted into a molecule similar to ATP.
• Electron carrier NAD+ changes to ____________
• Electron carrier FAD(flavine adenine dinucleotide)
changes to _________________
NADH
FADH2
What happens to each of the
Kreb’s Cycle Products?
• CO2 released is the source of all CO2 you exhale
• __________produced directly can be used for
cellular activities
• In the presence of O2,high-energy electrons from
electron carriers are used to make large amounts
of ATP.
ATP
Kreb’s CyCle
Section 9-2
Citric Acid
Production
Mitochondrion
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Section:
B. Electron Transport
•
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Kreb’s Cycle produces high-energy electrons
passed to NADH and FADH2
These electrons are passed from the electron
carriers to _______________________,which
uses high energy electrons from Kreb’s cycle to
convert ADP into ATP
Electron
Transport Chain
High energy electrons are passed from NADH and
FADH2 are passed along electron transport chain
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In eukaryotes,the chain is composed of carrier
proteins in the inner membrane of the
mitochondrion.
In prokaryotes,the same chain is in the
____________________
At the end of the chain,an enzyme combines
these electrons w/H+ ions and O2 to form
__________
O2,then ,serves as the final electron acceptor of
the electron transport chain,getting rid of
wastes(low energy electrons and H+ ions.)
Cell
membrane
H2O
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2) Every time 2 high energy electrons
transport down the transport chain,their
energy is used to transport H+ across the
membrane…..H+ ions build up in the
intermembrane space making it positive….
and the other side is negative.
3) How does the cell use the charge
difference?....The inner membranes of
mitochondria contain protein spheres called
ATP synthase….As H+ ions escape into the
proteins,the enzyme rotates,adding
phosphate to low energy ADP to make
_____.
ATP
On the average,each pair of high
energy electrons moves down the
chain,providing enough energy to
make 3 ATP from 3 ADP.
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
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Section:
The totals
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Glycolysis makes 2 ATP for each glucose
molecule
w/o O2,that’s all the energy extracted
w/ O2,the Kreb’s Cycle and the transport
chain make 34 more ATP(36 molecules
total,counting glycolsis)----18 x as much
These 36 molecules of ATP are 38% the total
energy in glucose…actually efficient
The other 62 % is released as
_______________---one reason why you feel
warmer after exercise
heat
D.Energy and Exercise
•
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Glycolysis covers a few seconds of a runners
run
• Next –lactic acid fermentation produces
ATP w/o O2 present
• At end of race,runner breathes extra to
use O2 to help rid body of lactic acid
• For long term energy(eg. Cross-country
running),cellular respiration releases a
continual supply of ATP
• Muscles store _____________ that help
out w/ about 20 min. of activity
After that,stored fats are broken down
glycogen
E. Comparing Photosynthesis & Cellular
Respiration
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__________________deposits energy by making
glucose
____________________withdraws energy by breaking
down glucose
Photosynthesis removes CO2 from atmosphere and
cellular respiration puts it back.
Photosynthesis releases ____ into atmosphere and
Cellular Respiration uses it to release energy from
food.
Cellular Respiration happens in eukaryotes and some
prokaryotes and________________________only
happens in plants ,algae and some bacteria.
O2
photosynthesis
photosynthesis
Cellular
respiration