Transcript Chapter 4- Cell Processes

Chapter 4- Cell
Processes
ATP
Photosynthesis
Cellular Respiration
Fermentation
By: Mrs. Stahl
Biology
How do we get our
energy?
 Chemical energy
Two Main Source of
Energy:
 Lipids
 Carbohydrates
Only useable after
it is broken down
by a series of
chemical reactions
Cells convert food > energy through
ATP-> adenosine
triphosphate
ATP
 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 has 3 phosphate
groups:
Third bond is unstable so it
is easily broken
When 3rd is removed its
releasing energy and turns
into ADP
phosphate removed
What is needed to change
ADP into ATP?
 Large group of complex proteins
and a phosphate
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
Swallow your food and then
digestion takes place. Does
each type of food have the
same amount of calories?
- NO!!!
- Different foods have
different calories therefore
provide different amounts of
ATP.
Summary
 The number of ATP molecule
depends on the carbohydrate,
lipid, or protein broken down.
 The organic compound most
commonly broken down to
make ATP is carbohydrates.
Summary Cont.
 Breakdown of sugar glucose
makes = 36 ATP
 Lipids store MOST of the
energy (ATP) and make up
80% of the energy in your
body.
 Fats broken down
Ex.- Triglycerides= 146 ATP
Summary……..
Proteins store about the
same as carbs but are
less likely to be broken
down.
Do plants need ATP?
 YES!!!!!!
 Plants make their own food
through photosynthesis where
they breakdown sugars -> ATP
Chemosynthesis
 Use chemical
energy from
sulfides instead of
light energy to
make carbon
storing molecules.
 Ex- hydrothermal
vents
http://www.youtube.com/watch?
v=BXGF3XS-yAI
Molecule Type Energy
Carbohydrate
4 cal. / mg
36 ATP
Lipid
9 cal./mg
146 ATP
Details
Most
commonly
broken down
for energy.
Produces the
most energy
for your body80%
Protein
4 cal. / mg.
Infrequently
used for
energy
usage
Photosynthesis
Chloro= green
chloroplast
Phyll= Leaf
Plast = Molded
leaf cell
leaf
Where does our energy
directly come from?
ATP
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.
Producers vs. Consumers
Producers /
Autotrophs
Make their own food
from the sun /
photosynthesis
Ex- plants, protists, and
bacteria
Consumers/
heterotrophs
Rely on others for food
Ex- you and other
animals
Photosynthesis is defined
as:
The process that
captures energy from
sunlight to make
sugars that store
chemical energy.
http://www.youtube.com/watch?
v=lDwUVpOEoE4
Functions:
 1. Biochemical process
 2. Plant cells only
 3. Plant growth and development
 4. Builds plants cell walls= cellulose
 5. Helps regulate Earth’s
environment
 6. Removes CO2 in the air
Several Types:
 UV radiation
 Microwaves
 Visible Light (what you see-
appears white but is made up of
several colors or wavelengths)
ROYGBIV
Chlorophyll
 Pigment in
chloroplasts, plants
only
 2 types:
 Chlorophyll a
 Chlorophyll b
Together they absorb
mostly red and blue
wavelengths. Neither
absorbs green light.
Green color comes
from the reflection of
lights green
wavelengths by
chlorophyll.
Carotenoids are
yellow-orange
pigments which
absorb light in
violet, blue, and
green regions.
When chlorophyll
breaks down in fall,
the yellow-orange
pigments in leaves
show through.
Fall Foliage
Photosynthesis occurs in
the………
 Chloroplast!!!!!!!!!
2 Main parts of
Chloroplast
 1. Grana->
Stacks of coin
shaped
membranes with
compartments
called thylakoids
that contain
chlorophyll, other
light absorbing
molecules, and
proteins.
Stroma
grana (thylakoids)
chloroplast
stroma
Fluid
that
surround
s the
grana
Equation for
Photosynthesis
Photosynthesis takes place
in 2 stages!
 Stage 1= Light dependent
Reactions
 Stage 2= Light Independent
Reactions
–
–
–
–
–
–
Light Dependent
Reactions
Requires sunlight
take place in thylakoids
water and sunlight are
needed
chlorophyll absorbs
energy
energy is transferred
along thylakoid
membrane then to lightindependent reactions
oxygen is released
Light Independent
Reactions
– Makes sugars
– takes place in stroma
– needs carbon dioxide
from atmosphere
– use energy to build a
sugar in a cycle of
chemical reactions
granum (stack of thylakoids)
1
chloroplast
6H2O
6O2
2
thylakoid
energy
stroma (fluid outside the thylakoids)
6CO2
1 six-carbon sugar
C6H12O6
3
4
Stage 1 in Detail
 Photosystems->Molecules that
capture and transfer energy in the
thylakoid.
Light Dependent
Reactions
 Sugars are not made yet
 Main function: capture and transfer energy
 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.
 Like a special ticket at an amusement
park that can only be used for a specific
rollercoaster.
 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
 Step 1-> Energy is absorbed from
sunlight
 Step 2-> Water molecules breakdown,
electrons enter, and oxygen is released
as waste.
 Step 3-> Hydrogen ions are transported
across the thylakoid membrane
 Step 4-> Chlorophyll absorbs energy
from sunlight
 Step 5-> NADPH is produced when
electrons are added to NADP+
Steps 6 and 7!!!
 Step 6-> Hydrogen ions diffuse
through a protein channel
 Step 7-> ADP is changed into ATP
when hydrogen ions flow through
ATP synthase (enzyme).
Calvin Cycle
 Does not need sunlight
 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 a
scientists- Melvin Calvin.
Steps
 1. CO2 is added to the 5 carbons that are
already there making a 6 carbon sugar
 2. ATP and NADPH is used from LDR to
split the six carbons into 2 groups of 3.
 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.
Light Independent / Calvin
Cycle- insert into notes
 Occur in the stroma
 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
Calvin Cycle Cont.
 A molecule of
glucose is formed as
it stores some of the
energy captured
from sunlight
 Two three-carbon
molecules bond to
form a sugar
 Remaining molecules
stay in the cycle
Questions on page 109
Figure 4.7
 1. Where do the light reactions
occur?
 Thylakoid membrane of the
chloroplast
2. What is the source of
the electrons in the ETC?
 chlorophyll
3. How are the electrons
released from the water
molecules used?
 To replace energized electrons that
leave the chlorophyll molecules
4. What role do these
electrons play?
 Provide energy to move hydrogen
ions into the thylakoid and to
produce molecules of NADPH
5. What two energy
carriers are produced?
 NADPH and ATP
6. In what step is active
transport occurring?
 Step 3
 Passive = Step 6
7. What enzyme speeds
the process up?
 ATP synthase
Page 111 Figure 4.6
 1. Where in the chloroplast do light
independent reactions occur?
 Stroma of the chloroplast
2. Where are the ATP and
NADPH coming from?
 Light dependent reactions
3. Why are these reactions
called a cycle?
 The five carbon molecule of the
process is regenerated, so the
cycle continues.
Who makes what?
Light Dependent makes
ATP
(photophosphorylation)
Light Independent makes
sugars
Quiz!!!!
 Indicate which system (PS1 or PS2 or
BOTH)
 ____1. Splits water
 ____2. Produces NADPH
 ____3. Has an electron transport chain
 ____4. Requires light
 ____5. Utilizes a primary electron acceptor
 ____6. Occurs in the thylakoid
 ____7. Requires the input of H20
 ____8. The cyclic path
 ____9. Uses chlorophyll
 ____10. Releases oxygen
Videos
 http://highered.mcgraw-
hill.com/sites/0072437316/student
_view0/chapter10/animations.html
#
 http://dendro.cnre.vt.edu/forestbi
ology/photosynthesis.swf
Factors that affect
photosynthesis:
1.
2.
3.
4.
5.
Light Quality (color)
Light intensity
Light Period
Carbon Dioxide Availability
Water Availability
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
Breathe in
oxygen and the
oxygen
releases energy
in sugars and
other carbon
based
molecules
ATP
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
2 Stages
Stage 1= Krebs Cycle
Stage 2= Electron
Transport
Krebs Cycle
 Produces
molecules
that carry
energy to the
second part.
 Occurs in the
matrix of
mitochondria
1
mitochondrion
ATP
matrix (area enclosed
by inner membrane)
and
6CO 2
energy
2
3
energy from
glycolysis
6O 2
and
inner membrane
ATP
and
6H 2O
4
 2- 3 carbons
from
glycolysis
through
pyruvate
enter the
cells matrix
 Pyruvate is broken
down before the
Krebs cycle.
 carbon dioxide released
 NADH produced
 coenzyme A (CoA)
bonds to two-carbon
molecule
Step 1
Step 2
Energy carrying molecules
transfer energy through the
matrix.
Stage 3
Energy is transferred to
the chain of proteins
(electron transport chain)
Stage 4
Large # ATP is made.
Heat and H2O are
released as waste
products.
End Result
 38 ATP molecules are made from 1
glucose molecule-> 2 glycolysis
and 34/36 come from cellular
respiration.
Product created in the body
via metabolism and is the
end product of glycolysis
 Pyruvate-> enzyme that speeds up
the phosphates
What enzyme is directly
associated with the Krebs
Cycle?
 Pyruvate and coenzyme a
What gets formed?
 Citric acid
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.
• Fermentation allows glycolysis to continue
making ATP when oxygen is unavailable.
 Fermentation is an anaerobic
process.
 occurs when oxygen is not available for
cellular respiration
 does not produce ATP
• Lactic acid fermentation occurs in muscle cells.
– glycolysis splits glucose into two pyruvate
molecules
– pyruvate and NADH enter fermentation
– energy from NADH converts pyruvate into lactic
acid
– NADH is changed back into NAD+
 Alcoholic fermentation is similar to lactic
acid fermentation.
 glycolysis splits glucose and the products
enter fermentation
– energy from NADH is used to split
pyruvate into an alcohol and carbon
dioxide
– NADH is changed back into NAD+
– NAD+ is recycled to glycolysis
Fermentation is used in food
production.
Yogurt
Cheese
Bread