Transcript Photosynthesis

Bell Ringer Question
Large quantities of proteins modified by
the Golgi apparatus exit the cell
through the process of
A)diffusion.
B)endocytosis.
C)exocytosis.
D)osmosis.
What is the name of the organelle that
carries the above proteins to the cell
membrane?
Photosynthesis
State Objectives!
CLE 3210.3.3 Investigate the
relationship between the processes of
photosynthesis and cellular respiration
SPI 3210.3.3 Compare and Contrast
photosynthesis and cellular respiration
in terms of energy transformation.
Introduction:
Overview
6 CO2 + 6 H2O +
light energy → C6H12O6 + 6 O2
Photosynthesis consists of two
independent pathways
light-dependent reaction (light reaction)
the light-independent reaction (dark
reaction).
Bell Ringer!!
Which is the BEST explanation for how fluid
pressure from freshwater helps plants to stand
upright?
A) Freshwater is a hypertonic solution, which causes the
plant cells to swell with turgor pressure.
B) Freshwater is a hypotonic solution, which causes the
plant cells to swell because of plasmolysis.
C) Freshwater is a hypertonic solution, which causes the
plant cells to swell because of plasmolysis.
D) Freshwater is a hypotonic solution, which causes the
plant cells to swell because of turgor pressure.
Introduction
Light Reactions: the energy in sunlight
is trapped, O2 is released, and both
ATP and NADPH + H+ (hydrogencarrier molecule) are formed
Dark Reactions: the ATP and NADPH +
H+ react with CO2 from the atmosphere
and form glucose
The entire process results in the
transformation of light energy from the
sun into energy stored in the bonds of
the glucose molecule.
Structure of a Chloroplast
The light
reactions take
place in the
thylakoid
membrane
The dark
reactions take
place in the
stroma
Structure of a Chloroplast
Electromagnetic Spectrum
Why are
plants
green?
Pigments
Pigments are light-absorbing
compounds.
Pigments appear colored because they
absorb light of certain wavelengths and
reflect that of others.
Chlorophyll a is the primary pigment in
green plants that absorbs red and
blue/violet light and reflects green light.
Structure
of
Chlorophyll
Why aren’t these leaves green??
Accessory Pigments
Chloroplasts also contain other pigments
called accessory pigments.
Accessory pigments trap wavelengths of light
that cannot be absorbed by chlorophyll a and
then transfer the energy to chlorophyll a
molecules for use in photosynthesis. In this
way, accessory pigments enable plants to
use a greater amount of the sun’s energy
than is available to chlorophyll alone.
Light Reaction
Light Reaction
Also called Light Dependent Reaction
Pigments that are in the chloroplasts
intercept light and begin the light reactions of
photosynthesis.
The light reactions occur in two
photosystems (located in the thylakoid
membrane): -photosystem I (PSI)
-photosystem II (PSII)
Photosystem: a unit of several hundred
chlorophyll a molecules and associated
acceptor molecules
Photosystems
Excited Electrons
NADPH
NADP+ is an electron acceptor
NADP+ + 2 e- + 2 H+
NADPH + H+
Bell Ringer!!
Do this on socrative!
Most animal cell membranes have proteins that
pump ______ ions out of the cell and potassium
ions into the cell.
A) calcium
B) carbon
C) magnesium
D) sodium
NOT using socrative – draw out the light
reactions of photosynthesis in as much detail
as possible.
State Objectives!
CLE 3210.3.3 Investigate the
relationship between the processes of
photosynthesis and cellular respiration
SPI 3210.3.3 Compare and Contrast
photosynthesis and cellular respiration
in terms of energy transformation.
Primary
Electron
Acceptor
ETC
Proton Pump
PSI
PSII
Lumen
Thylakoid
Water (H2O)
Oxygen (O2)
ATP Synthase
Hydrogen Ion (H+)
Electron
Step 1
Step 2
Step 3
Step 3
Step 3
Step 3
Step 3
Step 3
~
e
low
high
Step 4
Step 4
Step 4
Step 4
Step 4
Step 4
Step 5
Step 5
Step 5
Step 5
Step 5
NADP+
NADPH
+ H+
Step 5
high
low
Step 6
Step 6
Step 6
Step 6
Step 6
ADP + P
~
Step 6
e
ATP
NADP+
ADP + P
Reactants
O2 is
released
into the
atmosphere
NADPH
+ H+
DR
Products
ATP
1. A student is comparing hundreds of leaves of the
same tree species. The student will calculate each leaf
area using a formula. The formula requires the
measurements of length and width of each leaf. When
all the data are collected, the student will display
differences of leaves from the individual trees on a
graph. Which of these tools will the student use to
gather and display the data in this investigation?
A) microscope and digital balance
B) magnifying glass and hand calculator
C) metric ruler and spreadsheet program
D) Computer sensor and pie chart generator
2. What do you remember about the light reactions?
Get a copy of the worksheet
“Light Reactions”
The worksheet is on the computer cart
You may answer the questions at the
bottom of the worksheet.
State Objectives!
CLE 3210.3.3 Investigate the
relationship between the processes of
photosynthesis and cellular respiration
SPI 3210.3.3 Compare and Contrast
photosynthesis and cellular respiration
in terms of energy transformation.
Find a Partner
With your Partner: Quick Review
1.Where does
photosynthesis
happen?
2.Where do the
light reactions
happen?
3.What are the
reactants and
products of the
light reactions?
Where does it happen?
Two Stages:
● Light
Cycle:
●
thylakoid
●
Calvin
Cycle:
Takes place in
the stroma
Dark Reaction
Dark Reaction
The dark reaction is also
known as the Calvin Cycle,
after an American scientist
(Melvin Calvin) who figured
out the pathway.
The dark reaction is also
known as the C3 Cycle
because the first stable
products of this pathway are
molecules that contain three
carbon atoms.
The Calvin Cycle occurs in
the stroma.
Calvin Cycle
Reactants:
●
CO2 – from atmosphere
ATP & NADPH – from light cycle
Products:
●
Sugar & other monomers for
macromolecules such as amino
acids (proteins) and fatty acids
(lipids)
Calvin Cycle has 3 Parts.
1.Incorporates atmospheric CO2 into
existing organic molecules (carbon
fixation)
2. CO2 Reduction
3. Regeneration of RUBP
Calvin Cycle
6 CO2
C
6 RuBP
C C C C C
6 ATP
C C C
~
12 PGA
e
6 ADP + P
12 ATP
~
e
12 ADP + P
C C C C C C
Glucose
C C C
12 PGAL
C C C
e-
Making
Connections
Write out the chemical
formula for photosynthesis.
light + 6H2O + 6CO2
6O2 + C6H12O6
Some Botany (Plant) Stuff
Stomata (plural) stoma
(singular):
●
Specialized cells that
create a pore in the
leaves that allow air (CO2,
O2, water vapor) to come
and go.
Diffusion in Action
With your partner
Describe why plant cells may
want to close their stoma.
●
C4
vs.
CAM
WHY??
Exit Ticket
●Write out the chemical
formula for photosynthesis
and explain where each
element comes from.
The End!