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Cell Respiration
The cell needs something in
order to eat, breathe,
reproduce, move, and much
more……..
How do the cells get the energy they need?
• Chemical compounds we call FOOD!
 Convert chemical energy stored
in
food into compounds that are more
convenient for the cell to use
 Has 2 membranes
- Inner membrane
- Lots of FOLDS (cristae)= INCREASE
surface area= more ATP being
produced
- Outer membrane
 In Animal AND Plant cells
 Nearly all come from the ovum
 You get your mitochondria from your
mom!
Adenosine Triphosphate: nucleotide
with two extra groups
• Nitrogenous base- adenine
• Sugar- ribose
• 3 Phosphate groups- bound to
ribosome, phosphate tail holds
usable energy
• Body’s currency for energy
Partially
charged
that can
be fully
charged
by the
addition
of a
phosphate
group.
> Even if the equation looks simple, Cellular
respiration is done in a series of steps.
1. When energy is needed somewhere in the cell
2. Chemical energy stored in glucose is released and used to produce
adenosine triphosphate, ATP
3. ATP, is used for short term energy storage and transport in the cell
4. Energy is transferred from Glucose to ATP
5. Then ATP delivers the energy to the places in the cell that need it.
6. This is all done by a long and complicated process called Cell Respiration.
• High energy electrons produced
in these processes are highly
reactive and require a special
“carrier.”
• Think of it like a hot potato straight
from the oven.
• If you had to take it out of the oven,
you would get a mitt—a carrier—to
transport it.
 NADP+: accepts and holds 2 high-energy
electrons, a long with a hydrogen ion.
 This converts NADP+ to NADPH
 This is one way in which energy from
the sun can be trapped in chemical
form and transferred to other parts of
the cell.
 FAD and FADH2 are also electron carriers
 process by which cells release the energy stored in the bonds of
food molecules.
 From sugars, fats, amino acids, and nucleotides.
 However, GLUCOSE is the most important source of energy in
cells.
Aerobic process- requiring oxygen
Glycolysis
Glucose
Electron
Transport
Chain
Krebs Cycle
2 Pyruvic Acid
CO2 +NADH +
FADH2
H2O + 36 ATP
• Occurs in CYTOPLASM
• NO OXYGEN
After Glycolysis occurs:
• 2 Pyruvic acids enter the
Krebs Cycle
• 2 NADH goes to
Electron transport chain
• 4 ATP produced
• (Net gain of 2 per
glucose, since it took
2 ATP to start
glycolysis)
Glycolysis
• Occurs in the MATRIX
• Also known as citric acid
cycle because Citric acid is
the first compound formed
As Krebs Cycle Occurs:
• 3 CO2 is formed and released
into the air
• 2 ATP molecules formed
• Electron carriers: NADH
and FADH2 continue to
Electron Transport Chain
•
•
Reminder: Two pyruvic acids enter the
Krebs Cycle, so all of the above are
doubled
Hint: The 4 carbon compound that is
initially in the process comes from the
citric acid being broken down from a 6
carbon to a 5 then 4 carbon compound.
Krebs Cycle
• Occurs in Cristae (inner
membrane)
• Uses the high-energy
electrons from glycolysis and
the Krebs Cycle to convert
ADP into ATP.
• For every 2 Electrons that travel
down the chain, their energy
helps transport hydrogen ions
across into the intermembrane
space
• Charge difference forces
Hydrogen ions through ATP
synthase channels which
makes the enzyme spin.
• With each rotation, the enzyme
grabs an ADP and attaches a
phosphate group, making ATP.
• For every 2 Electrons= 3 ATP
Electron Transport Chain
Site of Cell Respiration: requires oxygen
(AEROBIC)
“Cell Respiration Song”
Three stages:
1. Glycolysis
1. Makes some ATP (4 to be exact)
2. Oxygen NOT needed
3. Location: CYTOPLASM
2. Kreb’s Cycle
1. Makes some ATP
2. Oxygen needed
3. MATRIX OF MITOCHONDRIA
3. Electron Transport Chain
1. Makes ALOT of ATP
2. Oxygen needed
3. Location: Inner membrane of
Mitochondria(CRISTAE)
 Aerobic
 Anaerobic
 “in air”
 “without air”
 REQUIRES OXYGEN
 DOES NOT REQUIRE
 Krebs cycle and Electron
Transport Chain
OXYGEN
 Glycolysis
 Fermentation
NO OXYGEN= FERMENTATION
-If there is no oxygen available, cell switches to fermentation
-Fermentation is Glycolysis over and over again
- Happens in cytoplasm
- Makes some ATP, but can do so quickly
-Alcohol Fermentation
-Bacteria and Fungi
-Such as yeast
-Produce ethyl alcohol and CO2
- Lactic Acid Fermentation
-In humans and mammals
-After exercising, you feel really sore
-It’s the lactic acid build up in your muscles
Yeast is a one-celled fungus that
converts sugar and starch into
carbon dioxide bubbles and
alcohol.
Cells get energy by:
•
•
•
•
•
•
Herbivores
Omnivores
Carnivores
Decomposers
detritivores
Scavengers
Autotroph
Heterotroph
• Obtain food by
consuming other
living things
• Consumers:
• Make
their own
food
• Producers
•Plant and bacteria cells only
(NEVER in animal cells)
•Captures energy from the
sunlight and convert it into
chemical energy
PHOTOSYNTHESIS
• Two membranes:
> inside has large stacks
of other membranes
that contain chlorophyll
Chloroplast
Cellular organelle where
photosynthesis occurs
Double membrane
Outer membrane
 Inner membrane
Stroma (fluid filled space)
Granum (stack of thylakoids)
Innermembrane space
 Thylakoids
Contains CHLOROPHYLL
Contain chemical compound
called chlorophyll-gives plants
their green color

1. Stomata (PLANT)
1. Small pores in the underside of leaves that
release water and oxygen and take in carbon
dioxide
2. Guard cells (PLANT)
1. Control the opening and closing of stomata
depending on environment
3. Stroma (CHLOROPLAST)
1. Thick fluid enclosed by the inner membrane
4. Thylakoids (CHLOROPLAST)
1. Disc-like sacs suspended in the stroma
2. Has membrane that surrounds inner thylakoid
space
5. Grana (sing. Granum) (CHLOROPLAST)
1. Stacks of thylakoids
Does this equation look familiar?
VS.
EVERYTHING IS MADE POSSIBLE BY THE SUN
AND THE PROCESS OF PHOTOSYNTHESIS!
• Energy from the sun travels to the earth in the
form of light.
• Sunlight, “white light” is actually a mixture of
different wavelengths.
• Our eyes see the different wavelengths of the
visible spectrum as different colors: red,
orange, yellow, green, blue, indigo, and
violet.
• Plants gather the sun’s energy with light-absorbing
molecules called PIGMENTS.
• Plant’s principle pigment is CHLOROPHYLL
• Chlorophyll a & Chlorophyll b absorb light in the blueviolet and red regions.
• DOES NOT absorb light well in the green region, it
reflects that color which is why we see plants as green.
-Carotene
-Secondary plant pigment
- Red and orange pigments
-Absorb light in other regions of the
spectrum
-So it reflects orange and red back to
us
Light-Dependent
Reaction
Light-Independent
Reaction
1. use energy absorbed
from chlorophyll and to
produce ATP and
NADPH
1. CALVIN CYCLE
2. Series of reactions that
form glucose from CO2 and
Water.
Lyn Margulis, American Biologist
said that chloroplasts descended
from prokaryotes
Organelle
DNA
• Mitochondria and
Chloroplasts contain their own
genetic information
• In a form of small, circular
DNA molecules
 Ancient Prokaryotes from way back in the day had a symbiotic relationship
with the ancient eukaryotes
 What is symbiosis?
• A relationship of mutual benefit or dependence.
•The prokaryotes lived inside the eukaryotes
•There were prokaryotes that used oxygen to make
energy (ATP)
•Mitochondria
• There were prokaryotes that used photosynthesis
to get energy
•Chloroplasts
AGAIN, DO YOU SEE
THE SIMILARITIES?