Transcript Cellular Respiration

Chapter 9: Cellular Respiration
CP Biology
Powerpoint
We run like cars
• Gasoline is to a car
what food is to
animals
• Mitochondria (the
engines of our cells)
– sugar is burned for
fuel
– the exhaust is CO2
and H2O
• In a car that burned
fuel perfectly, the only
exhaust should
theoretically be CO2
and H2O.
The Point of Cellular Respiration
• to harvest electrons from the food we eat
and use that energy to make ATP.
• ATP is broken down at a slow rate when
needed & provides energy for most of the
immediate work that the cell does.
What is a calorie?
• Energy is released when chemical bonds
in food molecules are broken.
• Energy is measured in a unit called a
calorie.
• Definition: the amount of energy needed
to raise the temperature of 1 gram of
water 1 degree Celsius.
General Equation for Cellular
Respiration
In symbols:
C6H12O6 + 6O2 -- 6CO2 + 6H20 + 36 ATP
In words:
Glucose + Oxygen  Carbon Dioxide + Water + ENERGY
Types of cellular respiration:
• There are two basic types of cellular
respiration:
• 1. Aerobic cellular respiration (with oxygen) &
• 2. Anaerobic cellular respiration (w/o oxygen).
Steps of Aerobic Respiration
• Step 1: Glycolysis (in cytoplasm/cytosol)
• Step 2: Kreb’s Cycle (in matrix of mito.)
• Step 3: Electron Transport System/Chain
(in inner membrane of mito.)
Use this
diagram to
complete
#11 on the
9.1
worksheet
Step 1
Step 2
Step 3
• The whole process of Respiration starts
with the intake of energy (food)!
Three energy storage molecules
involved in respiration
1.
: has two high energy bonds
2. NAD+: like a 2 passenger car that holds
electrons.
NAD+
•When the NAD+ is
NADH
holding 2 electrons
its called NADH.
3. FAD+: Is like NAD+, it carries 2 H
electrons becoming FADH2
Lets begin with the whole process!
Intake of food
“glucose”
Glycolysis begins……>
• Step 1: Glucose is converted into
fructose diphosphate (6c) by adding a
phosphate from the breakdown of 2
ATPs.
H+
e-
H+
e-
• Step 2: Two (3c) molecules of PGAL
are formed via oxidation. (losing 2 H
ions, 2 high energy electrons from the
fructose diphosphate).
• Step 3: Two NAD+ molecules accept
the 2 high energy electrons and
hydrogens making NADH.
• Step 4: Two phosphates are removed
from each PGAL creating two
molecules of pyruvic acid.
• Each phosphate (4) is used to make
ATP (4).
Step 1
H+
2e-
H+
2e-
Step 2
Step 3
Step 4
Glycolysis in summary:
• 2 ATPs (net gain)
• Pyruvate (pyruvic acid) is formed
• 2 NADHs
http://highered.mcgrawhill.com/sites/0072507470/student_view0/chapter25/animation__
how_glycolysis_works.html
Fill in the box
with correct #
of ATPs and
NADHs
Do Now!
1.
2.
3.
4.
In what part of the cell does glycolysis occur?
cytoplasm
What is the first chemical made from glucose?
Fructose diphosphate
How many ATP are needed to start glycolysis?
2
What are the two energy storage molecules
used in glycolysis? ATP & NADH
5. What is the NET gain of ATPs during
glycolysis? 2
6. What are the final products of glycolysis?
Pyruvic acid, 2 ATP. 2 NADH
• If Oxygen is available, the pyruvic acids in the
cytoplasm go into the mitochondria and the
Kreb cycle begins (Aerobic Respiration)
• If oxygen is NOT available, the pyruvic acids
stay in the cytoplasm and Fermentation begins
(Anaerobic respiration) .
(we’ll get to that later)
- where the Electron Transport Chain takes
place
- boundary between the organelle
and the environment
“folds” that
increase the
surface area
for more
ETCs
Place where the
Kreb’s Cycle
occurs
Intermembrane
space: reservoir
for H+ ions
which are used
to make ATP
from ADP
http://www.youtube.com/watch?v=TgJt4KgKQJI&feature=related
Aerobic Respiration
• is the process by which ATP is produced by cells
by the complete oxidation (removal of electrons)
of organic compounds using oxygen .
Stages in Aerobic Respiration
1. Once the pyruvic acid is inside the mitochondria,
carbon dioxide is removed from each three-carbon
pyruvic acid molecule to form acetic acid.
This little step
is the source
of some of the
carbon dioxide
we produce.
AEROBIC RESPIRATION
2. Acetic acid combines with an enzyme
called, coenzyme A, to produce acetyl
coenzyme A, also known as acetyl CoA.
3. Acetyl-CoA combines
with a 4-carbon
compound called
oxaloacetic acid,
producing 6C citric acid.
(The Krebs Cycle is aka
the Citric Acid Cycle)
4. Energy released by the
breaking and
rearranging of carbon
bonds is captured in
ATP, NADH, and
FADH2.
5. CO2 is released
Four types of products of the Kreb’s
Cycle:
1. Two high-energy
electron carriers
(NADH and FADH2)
2. Carbon dioxide
3. Two ATP molecules
(per glucose molecule)
4. Oxaloacetic acid
(needed to start the
cycle again)
DO NOW!
Carbon dioxide
Once the pyruvic acid is inside, _________________
is
removed from each pyruvic acid molecule to form acetic
acid.
2. Acetic acid combines with coenzyme A to produce :
1.
Acetyl-CoA
3 Acetyl-CoA combines with a 4-carbon compound,
producing a 6-carbon molecule called
Citric acid
_____________________.
4. Energy released by the breaking and rearranging of
carbon bonds is captured by what 3 energy storage
molecules?
ATP, NADH, FADH2
5. What gas is released? Carbon dioxide
6. In what part of the mitochondria does the Kreb’s Cycle
take place? Matrix
oxygen
7. The Kreb’s Cycle begins if _______________
is available.
Kreb’s Cycle
Where’s the Oxygen?
• The Kreb’s Cycle (Citric Acid Cycle)
occurs only when oxygen is present but it
doesn't use oxygen directly.
• Oxygen is directly used in Step 3:The
Electron Transport Chain.
Step 3: Electron Transport Chain
(Part A: Making water)
• The electron transport "chain" is a series
of electron carrying proteins in the inner
membrane of the mitochondria.
• These proteins transfer electrons from one
to another, down the chain.
• These electrons are added, along with
some of the H+ protons, to oxygen, which
is the final electron acceptor. This
produces water.
• The rest of the H+ ions, go through the ion
protein channel into the intermembrane
space.
Step 3: Electron Transport Chain
(Part B: Making ATP)
• The H+ ions build up in the
intermembrane space creating a
concentration gradient.
• The H+ ions diffuse back into the
matrix through the enzyme ATP
synthase.
• When The ATP synthase spins, it
creates energy which is trapped by
ADP creating ATP.
• The creating of ATP is known as
chemiosmosis.
• The electron transport chain
produces the remaining 32-34 ATP.
H+
The ETC
• http://www.youtube.com/watch?v=_PgjsfY
71AM
In Summary:
• The electrons pass down the chain of proteins until
finally oxygen is reached and water produced. Hence
the process is aerobic, that is, requiring oxygen.
• The hydrogens build up in between the inner and
outer mitochondrial membranes (increasing the
concentration gradient).
• The hydrogens diffuse through the ATP synthase
and the energy is captured in ATP.(This called
chemiosmosis.)
• 6O2 + C6H12O6 -- 36 ATP + 6CO2 + 6H20
• Music video:
http://www.youtube.com/watch?v=rVXHYx8zYeI&feature=rela
ted
(2 + 6)
Why does
Artificial Respiration work?
• Inhaled air: 78% nitrogen 21% oxygen
1% inert gas such as argon, carbon
dioxide little water vapor
• Exhaled air contains 78% nitrogen 17%
Oxygen, 4.5 % carbon dioxide and other
inert gases.
Photosynthesis and
Cellular Respiration Song
• “The Cycle Don’t Stop”:
• http://www.youtube.com/watch?v=65qBln
UTO3k&NR=1
Anaerobic Respiration
•
•
•
•
Respiration without oxygen
“Plan B” in animals
Produces 2 ATPs (from glycolysis)
Two types:
Depending on what kind of cell you
are, anaerobic respiration
(fermentation) will occur in one of
two ways.
• Fermentation
Lactic Acid
Alcohol
Anaerobic Respiration
• Animals and some bacteria
produce lactic acid.
• Demo
• Yeast and some bacteria produce
alcohol.
• Lab
Anaerobic Respiration
• As you might remember, the electrons collected
during glycolysis are carried away by NAD+
(forming NADH).
• W/O oxygen, the Kreb’s cycle cannot occur so the
NADH DO NOT enter the mitochondria they build
up in the cytosol/ cytoplasm instead.
• Without (recycled) NAD+s to carry away the
continually forming high energy electrons (from the
break down of
glucose),
glycolysis cannot proceed.
Shore
or
bust
NADH stuck in a traffic jam)
(The NADHs are
like cars
N
NADH
Anaerobic Respiration
Continued
• The NADH gives the 2 high energy
electrons to pyruvic acid thus freeing up
the NAD+ to collect more e- from glucose.
• Several products are created.
Remember me?
H+
e-
H+
e-
Glucose “Sugar, Sugar” Song
• http://www.youtube.com/watch?v=jJvALiiLnQ&feature=related
• “Hey There Delilah”
• http://www.youtube.com/watch?v=ClXcQ0
WFjkk
• The History of Yeast, Beer, and Bread
• http://www.youtube.com/watch?v=9v1cCE
uSJZg
Alcohol Fermentation:
Pyruvic acid + NADH ---- ethyl alcohol + NAD+ + 2 ATPs + CO2
• Occurs in yeast and some bacteria
• Makes bread (rise) and alcoholic beverages.
• Results in 2 ATPs and CO2 + alcohol
Formation of alcohol
Alcohol
•
•
•
•
•
•
Grapes ---- wine
Hops & barley ----- beer
Potatoes------ vodka
Rice ------- sake
Rye grain ------- whiskey
Sugarcane (molasses) ------ rum
FYI: Yeast die when alcohol levels reach 12%. The
alcohol becomes too toxic and they are poisoned. 
Is yeast safe?
• Yes and no
• Baker’s yeast or Brewer’s yeast is used
to make bread and alcoholic beverages.
These types of yeast are safe to ingest.
• There are some other types of yeast,
called Candidiasis, that can cause
infection.
What is a yeast infection?
• Animation:
http://www.youtube.com/watch?v=dtgcUQ
UrAxo&feature=related
• Where else can you get a yeast infection?
In your mouth
THRUSH
On your skin
In the cracks or folds of your
fingers, toes, armpit, and
other body creases (Interigo)
Erosio
interdigitalis
Yeast Lab
• See lab
• What do yeasts like to eat?
• http://www.youtube.com/watch?v=4mxqG
F9JZHI&feature=related
Lactic Acid Fermentation:
Pyruvic acid + NADH ---- Lactic acid + NAD+ + 2 ATPs
• Occurs in animals & some bacteria
• Results in sore, fatigued, “burning” or cramped
muscles within the first half hour of exercise.
• It takes approx. 40 minutes to lactic acid to clear
from your system.
• Creates 2 ATPs + lactic acid
• For short term energy production only (>90 sec).
• Animal cells begin to die within 4 to 6 minutes
without oxygen
How can you prevent &/or get rid of
Lactic Acid?
• Stretch : before and after
• Massage
FYI: Frequent cramps or cramps when NOT
exercising are often caused by a lack of
potassium, resulting from an electrolyte
imbalance.
Night leg cramps:
are most probably
caused by a mineral
deficiency of calcium
and/or magnesium.
If you are sore the day after
exercising..
• It is not from lactic acid.
• You are usually sore from small tears in
your muscles.
• Use heat to speed up healing
Lactic Acid (lactate) formation
Heart Rates in Different Mammals
• In humans, the average resting heart rate
is 70 to 80 beats per minute.
• Heart rates among mammalian species
are not at all similar. (Generally speaking, the larger the
animal, the slower its resting heart rate.)
HW: Half page essay:
•
•
•
•
•
•
•
1. What is lactic acid acidosis?
2. How do you get it?
3. What does it do to the body?
-Short term
-Long term
4. How do you get rid of it?
5. Anything else……. (Disease?)
Metabolism Quiz
• Honors Bio:
http://www.biology.arizona.edu/biochemist
ry/problem_sets/metabolism/metabolism.h
tml
Interactive Concept Map
• http://www.biologylessons.sdsu.edu/classe
s/lab4/semnet/cellular_respiration.htm
Cellular Respiration