Chapter 4- Cell
Processes
ATP
Photosynthesis
Cellular Respiration
Fermentation
By: Mrs. Stahl
Biology
Unit Layout
 Background knowledge
 Energy- where does it all come from?
 Review of Ecological Terms
 Food webs, food chains, and the transfer of energy
in ecosystems. All starts with sunlight and plants.
 ATP and ADP processes
 Photosynthesis
 Anatomy and functions of a plant.
 Process of photosynthesis and the importance of the
chloroplast.
 Cellular Respiration and Fermentation
 Bringing Photosynthesis and Cellular Respiration and
the relationship they have together.
How do we get our
energy?
 Chemical energy- starts with the
sun!
Two Main Sources of
Energy:
 Lipids
 Carbohydrates
Energy is only
useable after it is
broken down by a
series of chemical
reactions
Energy…………
•Energy for living things comes from food.
•Originally, the energy in food comes from the
sun and travels up the food web or food chain.
Let’s review some
terminology!!
 Ecology- The study of living things and
their surroundings.
 Organism- individual living thing.
 Species- a group of organisms that can
reproduce together and produce fertile
offspring. Ex- humans are the same
species.
 Population- group of the same species.
Ex- A group of bottlenose dolphins.
 Community- group of different
species living together. Exampledeer, rabbits, and birds.
 Ecosystem- Made up of both biotic
and abiotic factors. Example- rocks,
water, deer, rabbits
 Biome- A region or area that is
defined by the climate and plants
that grow there. Example- Tropical
Rain Forest.
 Biosphere- Planet Earth
 Biodiversity- Variety of life
 Abiotic- Non-living things. Ex- water, sunlight,
rocks
 Biotic-Living things. Ex- Plants and animals
 Keystone Species- species that keeps an
ecosystem in check / holds it together.
Example- Sea otters keep the sea urchin
population in check so that they don’t eat all
the kelp (algae).
 Producers / Autotrophs- make their own
food via sunlight. Example- Plants
 Consumers / Heterotrophs- rely on others
for food. Example- Animals
Autotrophs
Heterotrophs
Types of Consumers
 Herbivores- Eat only plants
 Carnivores- Meat eaters
 Omnivores- Eat plants and animals
 Detritivores- Eat detritus or dead
organic matter.
 Decomposers- Breakdown dead
organic matter into simpler
compounds.
Herbivores
Carnivores
Omnivores
Detritivores &
Decomposers
Energy Flow
 In ecosystems, energy has to flow
from one organism to another, and
it does this through food chains
and food webs, starting with the
sun and plants!
Food Web
 Network of feeding relationships
between trophic levels in an
ecosystem.
Arrows point in the direction
which the energy is flowing.
Food Chains
 Shows the feeding relationships for
a single chain of producers and
consumers.
Rabbit eats the grass and the hawk eats the rabbit.
How does the energy from the
sun flow through an ecosystem?
 Trophic levels
 Trophic levels are nourishment
levels in a food chain.
 Example- Producer- HerbivoreCarnivore = 3 Trophic levels
 Carnivores are the highest,
herbivore are second, and
producers are the first.
Break it down further…
– Primary consumers are herbivores that eat
producers.
– Secondary consumers are carnivores that
eat herbivores.
– Tertiary consumers are carnivores that eat
secondary consumers.
– Omnivores, such as humans that eat both
plants and animals, may be listed at
different trophic levels in different food
chains.
Trophic Levels
Shark
Triggerfish
Shrimp
Plants, algae,
phytoplankton
How does the energy get
distributed from trophic level to
trophic level?
 We know that ecosystems get their
energy from sunlight, which then
provides the energy for
photosynthesis to occur. That energy
then flows up the food chain.
 The amount of energy that gets
transferred from trophic level to
trophic level is 10% = Biomass
5
tertiary
consumers
secondary
consumers
primary
consumers
5000
Carnivores eat
herbivores and
more energy is
lost
500,000
Herbivores
eat plants but
burn some
energy in the
process
Energy
given off
as heat
producers
producers
5,000,000
Producers
use 100% of
energy from
the sun
How does life continue?
 The sun pumps more energy into
the plants allowing life to carry on.
How do organisms lose
energy?
 Metabolism
 Maintaining homeostasis- keeping your
body at normal temperature
 Mating, finding food, resting, movement,
growth,
 The same way we use energy so do other
organisms. That’s why we have to
continuously eat.
 Unused material = excreted as waste
Example
 Grass- Prairie Dog- Coyote
 1st- Grass=Photosynthesis traps
energy as carbohydrates = ENERGY!
 2nd Prairie dog eats the grass. The
prairie dog uses some of the energy to
grow, some is used to fuel cellular
respiration.
 The loss of energy between levels may
be as much as 90%, meaning that only
10% of energy is left over.
Some fun review!
 http://www.youtube.com/watch?v
=WLk-9ib0OVA
 http://www.youtube.com/watch?v
=GUY_-LK_lOc
ATP AND ADP- OUR
MAIN ENERGY
CURRENCY
phosphate removed
ATP- Adenosine
Triphosphate
 Molecule that transfers energy
from the breakdown of food
molecules to cell processes.
Starch molecule
Glucose molecule
Cells use ATP to:
1. Carry energy
2. Build molecules
3. Move materials by
active transport
ATP is made up of:
Sugar ribose
Adenine
Three Phosphates
ATP has 3 phosphate
groups:
Third bond is unstable so it
is easily broken
When 3rd is removed it’s
releasing energy and turns
into ADP
How is ATP made?
Breakdown of sugars
Starch molecule
Glucose molecule
How are sugars made?
By capturing energy
from sunlight and
changing it into chemical
energy stored in sugars.
How does ATP work
Exactly?????
 Step 1- The energy carried by ATP is released
when a phosphate group is removed from the
molecule. The third bond is unstable and is
easily broken.
 Step 2- Reaction takes place and the energy is
released for cell functions, meaning the third
phosphate fell off.
 Step 3- ATP (high energy) then becomes ADP
(lower energy molecule) because it just lost a
phosphate.
 Step 4-The molecules get broken down and
energy gets added.
 Step 5- Phosphate is added and it’s back to
ATP!
phosphate removed
What is needed to change
ADP into ATP?
 Large group of complex proteins
and a phosphate
Why is this important?
 The foods that you eat don’t contain
ATP.
 The food needs to be digested and
broken down
 Everything that you eat has a different
calorie amount (measures of energy),
therefore different foods produce
different amounts of ATP.
 The number of ATP produced depends on
what you eat- Carbohydrates, proteins,
or lipids.
Swallow your food and then
digestion takes place (NOT
THAT FAST OF COURSE!).
Does each type of food have the
same amount of calories?
- NO!!!
- Different foods have
different calories, therefore
provide different amounts of
ATP.
Carbohydrates
 Carbohydrates are not stored in
large amounts in your body
because they are the most
commonly broken down molecule.
 The breakdown of glucose yields
36 ATP.
 Carbohydrates DO NOT provide
the body with the most ATP. Lipids
do!
Lipids
 Store the most energy, about 80%
of the energy in your body.
 When they are broken down they
yield the most ATP, 146 ATP
Proteins
 Store about the same amount of
energy as carbohydrates, but they
are less likely to be broken down
to make ATP.
 The amino acids that cells can
break down to make ATP are
needed and used to build new
proteins.
Summary
 The number of ATP molecules
depends on the number of
carbohydrates, lipids, or proteins
broken down.
 The organic compound most
commonly broken down to make
ATP = carbohydrates.
Fun Video
 https://www.youtube.com/watch?
v=V_xZuCPIHvk
 http://www.youtube.com/watch?v
=xUpuuL24NiQ
 http://www.youtube.com/watch?v
=XI8m6o0gXDY
We know that plants use
photosynthesis, but what
about organisms that live
in the deep sea, where
there isn’t any sunlight?
Chemosynthesis
 Some animals don’t
need sunlight &
photosynthesis as a
source of energy.
 Chemosynthesisprocess by which
organisms use
chemical energy to
make their food.
 Example- Deep
Ocean Hydrothermal
Vents.
https://www.youtube.com/watch
?v=XotF9fzo4Vo
Mind Map
Produced
when
phosphate
is added
to ADP
Energy
Carrier
ATP
Releases
energy when
converted back
to ADP
Gets energy
from the
breakdown of
food
molecules
Do plants need ATP?
 YES!!!!!!
 Plants make their own food
through photosynthesis where
they breakdown sugars -> ATP
Photosynthesis
Defined as the process that
captures energy from sunlight to
make sugars that store chemical
energy.
Location- Chloroplast of plant
cells.
Photosynthesis
Chloro= Green
chloroplast
Phyll= Leaf
Plast = Molded
leaf cell
leaf
Chloroplast
Leaf
Cell
Leaf
Anatomy of a Flower
Female Parts
 Pistil= made up of the stigma, style,
ovule, and ovary.
 Stigma- Sticky portion that catches
the pollen.
 Style- tube that allows sperm /
pollen to be transported.
 Ovary- becomes the fruit
 Ovule- where the seed develops
Male parts
 Stamen- male parts made up of the
anther and the filament.
 Anther- Produces the pollen
 Filament- Support tube for the anther
 Sepals- green, tough region that protects
the flower before it opens.
 Receptacle- hard, base of the flower,
bears the organs of the flower
 Stem- support, transports water and
nutrients
Two Types of Seed Plants
Angiosperms
 Reproduce with
structures called
flowers and fruits.
 Brightly colored /
highly scented
 Attract animals->
transported from
place to place via
pollination, feces, and
wind
Gymnosperms
 Conifers- cone bearers
like pine trees.
 Naked seeds that
aren’t enclosed in a
fruit.
 Needle shaped leaves
with a protective
cuticle.
 Rely on wind for
pollination.
Angiosperms
Gymnosperms
Leaves
 Major site of photosynthesis / food
production.
 Minimize water loss by collecting water
and transpiration.
 Take in carbon dioxide and produce
oxygen through the stomata.
 Stomata’s are tiny pores in the leaf.
 Protects stems and roots with shade
and shelter.
Basic Structure
 Blade- collects the sunlight
 Petiole- stem that holds the leaf
blade up.
Upper portion / Top of the
leaf
 The tissue mesophyll, has most of
the chloroplasts and is where the
majority of the photosynthesis
takes place.
Bottom portion of the leaf
/ underside
 Has a stomata and is the site of
transpiration and gas exchange.
 Guard cells surround each stomata and
open and close by changing shape.
 Day- stomata is open, allowing the
carbon dioxide to enter and water to
evaporate.
 Night- close
Guard Cells
 Modified epidermal cells that are
photosynthetic and they open and close
the stomata.
 Potassium ions accumulate in the guard
cells and when there is a high
concentration of K+ it causes water to
flow into the cells. When the plant is full
of water, the guard cells plump up and
open the stomata.
Factors that affect the
stomata and guard cells
 Temperature, humidity, hormones,
and the amount of carbon dioxide
in the leaves tells the guard cells
to open and close
4 Types of Plant Tissues
 1. Ground Tissue
 2. Dermal Tissue
 3. Vascular Tissue
 4. Meristematic Tissue
Ground Tissue
most common and they
differ based on their cell
walls- 3 Types
1. Parenchymal
2. Collenchymal
3. Sclerenchymal
Parenchymal Cells
 The most common
plant cell typemesophyll
 Cell walls store and
secrete starch, oils and
water
 Help heal wounds to
the plant
 Have thin, flexible walls
Collenchyma Cells
 Provide support to a growing plant
 They are strong and flexible.
 Celery strings are strands of
collenchyma.
 They have unevenly thick cell walls.
Sclerenchyma cells
 Strongest, support, very thick cell walls
 Second cell wall hardened by lignin
 Die when they reach maturity
 Used by humans to make linen and rope
Dermal Tissue
 Covers and protects the outside
 Secretes cuticle of leaves
 Forms outer bark of trees= dead
dermal cells
 Epidermis= covers the surface, made
up of parenchymal cells
 Guard cells= surrounds the stomata
and has a cuticle that secretes a waxy
substance for protection.
Vascular TissueXylem & Phloem
Transports water, minerals,
nutrients, and organic
compounds to all areas of the
plant.
Made up of two networks of
tubes- xylem and phloem.
Phloem
 Carries the products of
photosynthesis through the plant via
active transport (products = oxygen
and glucose).
 Remember- PHLOEM IS FOR FOOD
 Part of the bark (at or near)
 Have little sieve tubes and plates
that help the fluid flow from one cell
to another.
Xylem
 Carries water and nutrients from
the roots to the rest of the plant.
 Found within the wood of the tree.
Tracheids- long, thin, overlapping
cells with tapered ends.
Vessel Members- wider, shorter,
thinner cell walls.
Meristematic Tissue
 Growth tissue
 Where cell division occurs
 Turns into ground, dermal, or vascular
 Apical Meristems- tips of roots and
stems-> primary growth occurs here.
 Lateral Meristems- secondary growth.
Increase the thickness of roots and
stems.
Seeds
 Monocots= one seed
 Dicots= two seeds
 Seed coat= protection
 Embryo
 Epicotyl- top, shoot tip
 Hypocotyl- attached to
the cotyledon, young
shoot
 Radicle- first organ from
the germinating seed->
becomes the root.
 Cotyledon or Endospermstores food for the
embryo
Environmental cues that
are required by the seed:
 Water, light, and temperature
 The seed is mature -> goes into a
dormant stage until all
environmental needs are met.
Germination allows the
seed to turn into a plant:
 1st- Water is absorbed
 2nd- Enzymes get triggered
 3rd- Chemical process= respiration
 4th- Water gets absorbed, causes the
seed to swell and the seed coat cracks.
 5th- Roots grow from the radicle and
anchor the seedling into the soil.
Hypocotyl grows to produce a young
shoot.
Roots and Stems
 Absorb nutrients
 Anchor the plant (hold it down)
 Store food
 They have specialized organs to
carry these out.
Root Organs
1. Epidermis- covers the outside
surface of the root
Has root hairs= increases surface
area and allows for more water to
be absorbed. They are constantly
being replaced.
2. Cortex- makes up most of the
root-> stores starch (sugars) in
the parenchymal cells.
3. Endodermis- tightly packed
ring of cells.
Has suberin, a waxy band that
surrounds each endodermis cell
in a barrier where water can’t
pass through called the
Casparian Strip-> controls the
movement of water and
minerals.
Root Growth
 Root Cap- tip, protects the apical
meristem where primary growth
occurs.
Stems
 Support leaves and flowers
 Move water and food
Fun Tree Rings
 Type of secondary growth
 Form due to uneven growth over the
seasons.
 Age of the tree is done by counting the
rings
 Lighter cell bands =spring growth
 Darker bands = later season growth
 During good growing seasons the rings
are thicker
Physiological Process
of Transpiration,
Photosynthesis, and
Cellular Respiration
Transpiration
 Evaporation of water from leaves
 Water is pushed up through the xylem by
root pressure created from water moving
up the soil to the plants root system and
into the xylem-> results in small droplets
of sap-> called guttation.
 Water is also pulled up through cohesion
through the xylem tissue-> creates a
negative pressure or tension from roots
to leaves.
Rate of Transpiration
 Slows in high humidity
 Accelerates or speeds up in low
humidity
 Increases with wind
 Increases with intense light=
increased photosynthesis and
water vapor
Photosynthesis
 Process of using sunlight as energy
to make carbon compounds
(glucose) to make food.
 Occurs in the chloroplast
 Two processes: Light reactions and
Light independent reactions
Equation
Functions of
Photosynthesis
 1. Biochemical Process
 2. Plant Cells only
 3. Plant growth and development
 4. Builds plant cell walls= cellulose
 5. Helps regulate the Earth’s
environment
 6. Removes CO2 from the air
Chloroplast
Three main parts are:
Grana- stacks of coined shaped
membranes.
Thylakoid
 Inside the grana and they are the
little disks. They contain chlorophyll
and other light absorbing pigments.
 Photosystems- light collecting units.
They proteins that organize
chlorophyll and other pigments into
clusters.
Stroma
 Fluid that surrounds the grana
inside the chloroplast.
Label the one in your
notes!!!!
Chlorophyll- the molecule in the
chloroplast that absorbs the
energy from the sunlight. Two
main types chlorophyll a and b
that absorb mostly red and blue
light. Other pigments absorb the
green.
Green color in plants comes from
the reflection of light’s green
wavelengths by chlorophyll.
Don’t have
to put this
in your
notes!!!
Just a little
fun fact!
Carotenoids are yelloworange pigments which
absorb light in violet, blue,
and green regions.
When chlorophyll breaks
down in fall, the yelloworange pigments in
leaves show through.
Fall Foliage
So let’s begin
 The sunlight hits the
leaves and CO2 is let in
through the stomata
(little pores) while H2O
is let in through the
roots.
Photosynthesis is broken down into two
different reactions!!!
1st
Light Dependent
Reactions or Light
Reactions
– Requires sunlight
– Take place in thylakoids
– Water and sunlight are needed
– Chlorophyll absorbs energy
– Energy is transferred along thylakoid membrane
then to light-independent reactions
– Oxygen is released
2nd
Light Independent
Reactions
 Uses the energy transferred from the light
dependent reactions to make sugars.
 Reactions occur in the stroma
 Does NOT require sunlight
 Carbon dioxide is absorbed and used at this
stage.
 Calvin Cycle- metabolic pathway found in the
stroma of the chloroplast in which carbon
enters in the form of CO2 and leaves in the
form of sugar.
 ATP is produced as a final step and the
enzyme ATP synthase is responsible for
making ATP by adding phosphate groups to
ADP.
The whole process in
simple terms……….
 Step 1- Chlorophyll absorbs energy from
sunlight. Energy is transferred along the
thylakoid membrane, water molecules are
broken down, and oxygen is released.
 Step 2- Energy carried along the
thylakoid is transferred to molecules that
carry energy, like ATP
 Step 3- CO2 is added and larger
molecules are built.
 Step 4- A molecule of simple sugar
(glucose) is formed.
Calvin
Cycle
Questions to review
 1. Where do the light dependent
reactions occur?
 2. Where do the light independent
reactions occur?
 3. What two reactants are shown
entering the chloroplast?
 4. What two products are shown
leaving the chloroplast?
 5. What does the Calvin Cycle
produce?
Answers
 1. Thylakoid membrane
 2. Stroma
 3. Water and carbon dioxide
 4. Oxygen and sugar
 5. Sugar- converts CO2 into sugar
Videos
http://www.youtube.com/watch?
v=lDwUVpOEoE4
Now that we have a brief
overview let’s look at it in
a little more detail.
Light Dependent
Reactions
 Main function: capture and transfer energy
 Broken down into Photosystem 2 / Electron
Transport and Photosystem 1 / Energy carrying
molecule.
 Water molecules are broken down into
hydrogen ions, electrons, and oxygen gas.
Oxygen is a waste product and sugars are not
made at this point.
 Energy is transferred to electrons.
 Electrons are used for energy during
photosynthesis NOT for the cells general energy
needs.
Light Dependent Cont.
 Electron Transport Chain (ETC)- series of
proteins in the membrane of the thylakoid.
 Energy-> electrons->ATP and NADPH
(transferred to the later stages)
 Arrows represent energy and enzymes!
 NADP= coenzyme that can accept hydrogen
and acts as an enzyme
http://www.biologyonline.org/dictionary/Nicotinamide_adenine_di
nucleotide_phosphate
Lets put it all together, first stop
Photosystem 2 and ETC
 Step 1-> Energy is absorbed from sunlight via
chlorophyll and other pigments. Energy is
transferred to the electrons which enter the
ETC.
 Step 2-> Water molecules are broken down by
enzymes and oxygen is released as waste.
 Step 3-> Electrons jump from protein to
protein down the ETC and their energy is used
to pump the Hydrogen ions from outside to
inside the thylakoid membrane (against the
concentration gradient = ACTIVE TRANSPORT)
Photosystem 1 and Energy
Carrying Molecules
 Step 4-> Energy from sunlight continues
to be absorbed, energizing electrons and
pushing them along the ETC.
 Step 5-> Electrons are then added to the
molecule NADP+ (functions like ADP) to
produce NADPH (functions like ATP).
 Step 6-> Hydrogen ions diffuse through a
protein channel.
 Step 7-> ATP is produced. ADP is
changed into ATP when hydrogen ions
flow through ATP synthase (enzyme).
Now that we have
completed all the steps of
the light reactions, now
we need to finish the
process of photosynthesis
with the dark reactions or
light independent
reactions!
Calvin
Cycle
Light Independent /
Calvin Cycle
 Uses the ATP from light dependent reactions.
ATP is crucial because without it the reaction
would not happen.
 Does not need sunlight
 Occurs in the stroma and produces sugars
 Energy sources are ATP and NADPH
 Energy that is needed for a series of chemical
reaction is called the Calvin Cycle, named after
the scientist- Melvin Calvin.
Light Independent / Calvin
Cycle continues
* A molecule of glucose is formed as it
stores some of the energy captured from
sunlight.
 Carbon dioxide molecules enter the Calvin
cycle
 Energy is added and carbon molecules are
rearranged
 A high-energy three-carbon molecule leaves
the cycle
Steps in Detail….
 1. CO2 is added to the 5 carbons that are
already there making a 6 carbon sugar.
 2. Energy is added. ATP and NADPH is used
from LDR to split the six carbons into 2
groups of 3, and to keep the cycle going.
 3. Three carbon molecules exit. After they
both exit they bond together to form glucose.
 4. Three carbon molecules are recycled and
changed back to five carbon molecules by
energy from ATP. It takes two turns of the
Calvin Cycle to produce 1 molecule of
glucose.
Review Questions
 1. Where do the light reactions occur?
 2. Where do the electrons come from in
the ETC?
 3. What role do these electrons play?
 4. What two energy carriers are
produced?
 5. When does active transport take
place?
 6. What enzyme speeds up the process?
 7. Where in the chloroplast do light
independent reactions occur?
 8. Where does the ATP and NADPH come
from for the light independent reactions?
 9. What does the LDR make? What does
the LIR make?
 10. How many cycles or turns does it
take to make one glucose molecule?
Answers
 1. Thylakoid membrane
 2. Chlororphyll
 3. Provide energy to move hydrogen ions
into the thylakoid and to produce
molecules of NADPH
 4. NADPH and ATP
 5. Step 3 when hydrogen ions are
transported
 6. ATP synthase
7. Stroma
8. LDR
 9. LDR= makes ATP, LIR= makes sugars
 10. 2
Let’s Summarize
Write the Equation for Photosynthesis
Process
Light Dependent
Reactions
Where the
photosystems
take place.
Light
Independent
Reactions.
Where the Calvin
Cycle takes place
Location
Reactants
Ending Products
Let’s Summarize
6CO2 + 6H2O -> C6H12O6 + 6O2
Process
Location
Reactants
Ending Products
Light Dependent
Reactions
Thylakoid
Membrane
Sunlight
H2O
ATP
NADPH
O2
Stroma
ATP
NADPH
CO2
Glucose
Where the
photosystems
take place.
Light
Independent
Reactions.
Where the Calvin
Cycle takes place
Videos
http://www.youtube.com/watch?v=
k17bJQSQeQ4
Now we take
photosynthesis and see
how we, HUMANS and
other organisms use it
through a process called
Cellular Respiration.
Cellular Respiration!!
Releases chemical energy
from sugars and other
carbon based molecules to
make ATP when oxygen is
present.
By the time you reach
16 you have taken
about 200 million
breaths
FUN
FACT!
Animals use cellular
respiration
Plants use photosynthesis
Breakdown food-> ATP
Aerobic-> Need Oxygen
Anaerobic= no oxygen
Takes place in the
Mitochondria
After you eat and the food is
broken down into glucose then
the glucose needs to get
broken down by glycolysis (2-3
carbon chains, ATP), which
takes place in the cytoplasm
and is anaerobic.
Glycolysis
Glycolysis
 Ongoing process in all cells
 Happens before cellular respiration in the
cytoplasm, outside the mitochondria
 Anaerobic= no oxygen required
 Makes a small number of ATP molecules.
Makes 4 ATP, BUT it uses 2 to split up the
carbons, therefore only 2 ATP molecules enter
the mitochondria.
 Series of reactions converts the three-carbon
molecules to pyruvate / pyruvic acid.
 Pyruvate and NADH are used for cellular
respiration.
What is pyruvate?
 Our bodies actually make it
naturally during metabolism and
when we digest sugars and
starches. It is crucial for the Kreb’s
cycle in cellular respiration.
2 Stages
Stage 1= Krebs Cycle
Stage 2= Electron
Transport
Krebs Cycle
 Main function- transfer high energy
electrons to molecules that carry
them to the ETC
 Occurs in the matrix of mitochondria
 Also known as the Citric Acid Cycle
because it’s the first molecule
formed.
1
mitochondrion
ATP
matrix (area enclosed
by inner membrane)
and
6CO
2
energy
2
3
energy from
glycolysis
inner membrane
ATP
and
and
6O
6H O 2
2
4
Step 1
 Pyruvate is broken
down into 2 carbon
molecules and CO2 is
released as a waste
product.
 NADH is produced
Step 2
 Coenzyme A bonds to the 2 carbon
molecule made from pyruvate and enters
the Kreb’s Cycle.
 Acetyl-CoA is one of the most important
molecules in the body because all
nutrients (carbs, lipids, and proteins)
generate it when they break down. This
molecule is produced in large amounts
and is pumped into the Kreb’s cycle if the
body is in need of energy, or into
synthesis of fat to be stored for later use.
Step 3
 Citric Acid is formed- the two
carbon molecule binds with a four
carbon molecule to make a six
carbon molecule which is called
citric acid.
Step 4
 Citric acid is broken down
 NADH is made
 CO2 is given off as a waste
product.
Step 5
 Five carbon molecule is broken
down
 Four carbon molecule, ATP, and
NADH are formed.
 NADH leaves the Krebs cycle
Step 6
 Four carbon molecules are
rearranged
 High energy electrons are released
 NADH and FADH2 (electron
carrier) are made
One Molecule of Pyruvate
makes these products:
 3 molecules of CO2 have been
given off
 1 molecule of ATP
 4 molecules of NADH2 to the ETC
 1 molecule of FADH2 to the ETC
If Glycolysis produces 2
molecules of pyruvate,
how much of each product
do we have????
Answer
 6 molecules of CO2 have been
given off
 2 molecules of ATP
 8 molecules of NADH2 to the ETC
 2 molecules of FADH2 to the ETC
Electron Transport Chain
 Takes place along the inner
membrane of the mitochondria
 Made up of proteins
 Proteins use energy from NADH and
FADH2 to pump hydrogen ions
against the gradient (active
transport)
Step 1
Proteins take electrons.
They take 2 NADH and 1
FADH2.
Step 2
 Proteins use energy from the
electrons to pump the hydrogen
ions through the inner membrane
and the hydrogen ions build up on
the inside of the membrane.
Step 3
 ATP is produced
 Flow of hydrogen ions helps make
the ATP
 ATP synthase adds phosphate
groups to ADP to make the ATP
molecules.
 For each pair of electrons that
passes through 3 ATP molecules
are made.
Step 4
 Oxygen enters and water is
formed.
 Water is given off as a waste
product
End Result / Products of
Cellular Respiration
 CO2 and pyruvate (from Kreb’s)
 H2O from the ETC
 Net gain of about 38 ATP molecules are
made from 1 glucose molecule->
 2 glycolysis
 2 from Kreb’s Cycle
 34 from the ETC
Photosynthesis
Cellular Respiration
Location
Chloroplast
Mitochondria
Reactants
CO2 and H2O
C6H12O6 and O2
Products
C6H12O6 and O2
CO2 and H2O
Electron
Transport
Chain
Proteins within the thylakoid
membrane
Proteins within the inner
mitochondrial membrane
Cycle of
chemical
reaction
Calvin cycle in the stroma of
chloroplasts builds sugar
molecules.
Krebs cycle in matrix of
mitochondria breaks down
carbon based molecules.
What happens to your
cells when there isn’t
enough oxygen to keep
cellular respiration going?
Fermentation
 Allows glycolysis to continue
 Does NOT make ATP
 Removes electrons from NADH and
recycles NAD+
 Important for NAD+ to still pick up
electrons because if it didn’t, glycolysis
would stop and wouldn’t be able to make
ATP.
Lactic Acid Fermentation
 Occurs when oxygen is unavailable
 Causes your muscles to be sore / burn
 When oxygen is available your cells
return to using cellular respiration and
the lactic acid is broken down / removed.
This is why you breathe heavy after
exercising and it takes a few minutes to
recover because your body is trying to
recover from the oxygen depletion in
your muscle cells.
Alcoholic Fermentation
 Forms the same way as the other two:
Glycolysis splits a molecule of glucose to
make 2 ATP, 2 pyruvate, and 2 NADH
molecules.
 Occurs in many yeasts- CO2 causes the
dough to rise
 End product is CO2, NAD+, and ethyl
alcohol
Fermentation is used in food
production.
Yogurt
Cheese
Bread