chapter 8: photosynthesis. 8-1 energy of life energy= living organisms depend on energy. living...
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CHAPTER 8: CHAPTER 8: PHOTOSYNTHESISPHOTOSYNTHESIS
8-1 Energy of Life
Energy=
Living organisms depend on energy.
Living things get energy from _______.
The ultimate source of energy is the _____.
The ability to do work
food
sun
A. Autotrophs and Heterotrophs
Autotrophs=
o Example: plants use sunlight to make food
Heterotrophs=
o Example: ___________- eat plants ___________- eat animals that have stored energy from plants they eat
___________- eat decomposing organisms
Organisms that make their own food
Organisms that need to consume food for energy
herbivores
carnivores
detritovores
Adenine Ribose 3 Phosphate groups
Section 8-1
ATPB. Chemical Energy and ATP•Forms of energy: light, heat, electricity, and
•_____ (Adenosine Triphosphate)=
Chemical energy (stored in bonds)
ATP
The basic energy source (chemical energy) of all cells
1. Storing Energy
• ADP (Adenosine Diphospate) contains ____ phosphates instead of 3.
• If a cell has extra energy,
2. Releasing Energy
• To release energy stored in ATP,
2
Small amounts can be stored by adding a phosphate group to ADP molecules to produce ATP.
The cell can break the high energy bond betweenthe 2nd and 3rd phosphate group
ADP ATP
Energy
EnergyAdenosine diphosphate (ADP) + Phosphate Adenosine triphosphate (ATP)
Partiallychargedbattery
Fullychargedbattery
Section 8-1
Figure 8-3 Comparison of ADP and ATP to a Battery
C. Using Biochemical Energy
How ATP is used in the cell- - aids in - -
Cells contain a small amount of ATP. Only enough to provide a few seconds of activity.
ATP is great at ________________ but not good at
C. Glucose stores ___ times more energy than ATP.
The energy stored in Glucose can be used to
Carry out active transportmoving organelles throughout the cell
Protein synthesisProducing light (ex. fireflys)
transferring energy Storing large amounts of energy
90
regenerate ATP when the cell needs it.
8-2 Photosynthesis: An Overview
Photosynthesis=
Plants convert ______________ into ______________ through a series of oxidation/reduction reactions.
Process where plants use energy of sunlight to convert water and carbon dioxide into high-energy Carbohydrates-sugars-starches-and oxygen, a waste product.
Sunlight energy Chemical energy
6 CO2 + 6H2O + SUNLIGHT → C6H12O6 (SUGAR) + 6O2
6 CO2 + 6H2O + SUNLIGHT → C6H12O6 (SUGAR) + 6O2
sunlight
O2
CO2
H2O
C6H12O6
Reduction: Gain electrons
Oxidation: Lose electrons
REDOX REACTIONSLEO: Lose Electrons Oxidationgoes GER: Gain Electrons Reduction
Light Energy
Chloroplast(Chlorophyll)
CO2 + H2O
Sugars + O2
Section 8-2
Photosynthesis: Reactants and Products
A. Investigating Photosynthesis Investigations into photosynthesis began with the following question:
“When a tiny seedling grows into a tall tree with a mass of several tons, where does the tree’s increase in mass come from?”
1. ______________ Experiment (1643)
Put soil in pot and took mass
Took a seedling and took mass
Put seed in soil...watered...waited five years... the seedling became a tree.
He concluded that He determined the
Van Helmont’s
the mass came from water
“hydrate” in the carbohydrate portion of photosynthesis
Von Helmont Willow Tree Experiment
http://www.teachersdomain.org/resource/tdc02.sci.life.stru.photosynth/
2.3 kg. (5 lb.) plant90.8 kg (200 lbs). soil
76.8 kg (169 lbs. 3 oz.) Soil 57 g less
5 years
2. ___________ Experiment (1771)
Put a lit candle in a bell jar- Placed a mint plant in the jar with the candle-
Concluded
He determined
Priestly’s
The flame died out.
Flame lasted longer
plants release a substance neededfor candle burning.
plants release oxygen
Alternate Priestly Experiment
•Credit: The National Science Teachers Association
3. ________________Experiment (1779)
Put aquatic plants in light...
Put aquatic plants in dark... He determined:
4. _______________ (1948)
He determines
Known as the
Jan Ingenhousz
produced oxygen
No oxygen
Light is needed to produce oxygen
Melvin Calvin
carbon’s path to make glucose
Calvin’s cycle
B. Light and Pigments Photosynthesis requires ______ (soil), ____________ (air), and ____ (sun), and ________ (a molecule in chloroplasts).
Energy from the sun is in the form of _____.
Sunlight= perceived as white light=
The wavelengths you can see are part of the _______________.
Plants capture light with light absorbing molecules called ________.
The main pigment is chlorophyll (2 kinds)1. 2.
water Carbon dioxidelight chlorophyll
light
A mixture of different wavelengths
Visible Spectrum
pigments
Chlorophyll a
Chlorophyll b
Absorption of Light byChlorophyll a and Chlorophyll b
V B G YO R
Chlorophyll b
Chlorophyll a
Section 8-2
Figure 8-5 Chlorophyll Light Absorption
Chlorophyll absorbs light in the __________ and ___ wavelengths
Gammarays
X-rays UV Infrared Micro-waves
Radiowaves
Visible light
Wavelength (nm)
Blue-violetred
RED
ORANGE
YELLOW
GREEN
BLUE
INDIGO
VIOLET
Chlorophyll reflects ______ wavelengths (that’s why plants appear green)
The energy absorbed by chlorophyll is transferred to _________ (in chloroplasts) which makes photosynthesis work.
green
electrons
QUESTION: So why do plants leaves change color in the fall?
Colorful leaves signal the changes of autumn. As nights grow longer and cooler, the leaves no longer produce chlorophyll, the pigment that makes leaves green and enables the process of photosynthesis. As the green pigment wanes, other pigments take over, producing the brilliant reds, oranges, and yellows of fall foliage.
• The location and structure of chloroplasts
Figure 7.2
LEAF CROSS SECTION MESOPHYLL CELL
LEAF
Chloroplast
Mesophyll
CHLOROPLAST Intermembrane space
Outermembrane
Innermembrane
ThylakoidcompartmentThylakoidStroma
Granum
StromaGrana
Light
Chloroplast
Reflectedlight
Absorbedlight
Transmittedlight
8-3 The Reactions of Photosynthesis A. Inside a Chloroplast
•Site of Photosynthesis=
The chloroplasts
Photosynthesis is a two part process:1.
-aka: 2.
-aka: -aka: -aka:
ChloroplastLight
O2
Sugars
CO2
Light-Dependent Reactions
CalvinCycle
NADPHATP
ADP + PNADP+Chloroplast
Section 8-3
Figure 8-7 Photosynthesis: An Overview
Light-dependent reactions (located in thylakoid membranes)Light Reaction
Light-independent reactions (located in stroma)Dark reactionCalvin CycleCarbon fixation
H20
• An overview of photosynthesis
Figure 7.5
Light
Chloroplast
LIGHTREACTIONS
(in grana)
CALVINCYCLE
(in stroma)
Electrons
H2O
O2
CO2
NADP+
ADP+ P
Sugar
ATP
NADPH
B. Electron Carriers Sunlight energy is transferred to
The electrons
High energy electrons require ANALOGY: If you wanted to transfer hot coals from one campfire to another, it requires a special carrier like a pan or bucket.
Electron carriers pass electrons from carrier to carrier to carrier;
A Key electron carrier in photosynthesis is NADP+. NADP+ + + →→ (electron carrier) (high energy electrons) (hydrogen ions) (energy storing compound)
When energy is needed to do cellular work, the
electrons in chlorophyll.
gain a lot of energy.
a special carrier (molecule/compound).
Forming an electron transport chain.
2e- H+ NADPH
Covalent bonds of NADPH are broken to releasethe high energy electrons.
C. Light-Dependent Reactions (Requires Light)· Located in the ___________________________
· In the light reaction, ___________ is used to
produce _____ and _______
http://www.fw.vt.edu/dendro/forestbiology/photosynthesis.swf
thylakoid membrane
light energyATP NADPH
PSII PSI
2H2O
O2 + 4H+
Electron Transport Chain
NADP+ NADPH
Electron Transport Chain
light
light
ADP ATPe~
4e~
e~
e~
e~
e~
e~
Overview of the Light Reaction
http://www2.kumc.edu/netlearning/examples/flash/photosyn2.html
Primaryelectron acceptor
Primaryelectron acceptor
Electron transport chain
Electron transport
Photons
PHOTOSYSTEM I
PHOTOSYSTEM II
Energy forsynthesis of
by chemiosmosis
http://www2.kumc.edu/netlearning/examples/flash/photosyn2.html
KEY PLAYERS IN LIGHT REACTION:
Photosystem I and II:
Electron carriers:
Water:
• ATP Synthase:
Clusters of chlorophyll pigment
ADP and NADP+
Donates electrons
Enzyme (protein) that makes ATP
Figure 7.7C
Primaryelectron acceptor
Photon
Reaction center
PHOTOSYSTEM
Pigmentmoleculesof antenna
HydrogenIon Movement
Photosystem II
InnerThylakoidSpace
ThylakoidMembrane
Stroma
ATP synthase
Electron Transport Chain Photosystem I ATP Formation
Chloroplast
Light Reaction Process:
• The production of ATP by chemiosmosis in photosynthesis
Figure 7.9
Thylakoidcompartment(high H+)
Thylakoidmembrane
Stroma(low H+)
Light
Antennamolecules
Light
ELECTRON TRANSPORT CHAIN
PHOTOSYSTEM II PHOTOSYSTEM I ATP SYNTHASE
A. Photosystem II (PSII) * Absorbs light to
2H2O
o e- =
o O2 =
o H+=
B. Electron Transport Chain * The light energy
* The electrons get passed
split (break up) water molecules
→ 4H+ + 4e- + O2
Donated to chlorophyll
Released into air providing oxygen for us
Released inside the thylakoid membrane
excites electrons increasing their energy level.
down an electron transport chain tophotosystem I (PSI)
C. Photosystem I· Light energy energizes electrons.· NADP+ accepts the electrons and an H+ and are
used to make _________. D. Hydrogen Ion Movement
· When water splits,
· The difference in charges
http://highered.mcgraw-hill.com/olcweb/cgi/pluginpop.cgi?it=swf::535::535::/sites/dl/free/0072437316/120068/bio05.swf::Proton%20Pump
E. ATP Formation· _____ do not cross the membrane directly.
It needs the help of a membrane protein.· H+ ions pass through the protein:
NADPH
H+ ions fill up the inner thylakoid membrane (making it positively charged). As a result, the stroma is negatively charged.
Provides the energy to make ATP.
Ions
ATP synthase is an enzyme that converts ADP to ATP
PRODUCTS OF THE LIGHT REACTION:
· ____ : Released in the air
· ______________: These contain abundant chemical energy but they are unstable. So, they are used to power the dark reaction to _________________ which can store the energy for longer periods of time.
O2
ATP & NADPH
help build glucose
ChloropIast
CO2 Enters the Cycle
Energy Input
5-CarbonMoleculesRegenerated
Sugars and other compounds
6-Carbon SugarProduced
Section 8-3 D. The Calvin Cycle (dark reaction; light independent) * Occurs in the
http://faculty.nl.edu/jste/calvin_cycle.htm
Figure 8-11 Calvin CycleStroma with or without light.
The Calvin Cycle The Calvin Cycle
(CO2)
(Unstable intermediate)
ATP
ADP +
ADP +
(Sugars and other carbohydrates)
NADPH
NADP+
(PGAL)
(PGAL)
ATP
(PGAL)
(RuPB)
DARK REACTION PROCESS: A. CO2 enters the system• • product=
B. Energy input• The _________________________________ are used to
C. 6-Carbon Sugar is produced• ___ of the 12 3-C are used to make glucose and other compounds.
D. 5-Carbon Molecules Regenerated• ___ remaining 3-C are converted into 6 5-C molecules
6 CO2 combines with 6 5-C compounds12 3-C compounds
ATP & NADPH (from the light reaction)convert the 12 3-C compounds into a higher energy form.
2
10
PRODUCTS OF THE CALVIN CYCLE (DARK REACTION):*
E. Factors Affecting Photosynthesis* * Plants often have a ______ coating to protect against
* * The greater the _____________, the better photosynthesis functions (up to a point).
High Energy Sugars
Shortage of water can stop/slow down photosynthesis
waxy
Very low/high temperatures (damages enzymes) can stop/slow down photosynthesis (optimal temp.= 0°– 35° C
Light intensity
Photosynthesis
includes
of
take place intakes place in uses
to produce to produce
use
Light-dependentreactions
Calvin cycle
Thylakoidmembranes Stroma NADPHATPEnergy from
sunlight
ATP NADPH O2 Chloroplasts High-energysugars
Section 8-3
Concept Map
California State StandardsCalifornia State Standards
Cell BiologyCell Biology
1a: usable energy is captured from 1a: usable energy is captured from sunlight by chloroplasts and is stored sunlight by chloroplasts and is stored through the synthesis of sugar from through the synthesis of sugar from carbon dioxidecarbon dioxide
Warm up 8-1Warm up 8-1
Draw an ATP molecule and describe why it is Draw an ATP molecule and describe why it is considered an energy molecule.considered an energy molecule.
Why do animals have to eat to gain energy and Why do animals have to eat to gain energy and plants do not?plants do not?
Why do organisms need energy?Why do organisms need energy?
Warm-up 8-2Warm-up 8-2
Describe what the data represents in figure 8-5 Describe what the data represents in figure 8-5 pg 207.pg 207.
Why are plants green?Why are plants green?
What do plants need to grow? Where are they What do plants need to grow? Where are they obtaining these substances?obtaining these substances?
Warm-up 8-3Warm-up 8-3
Diagram the process of photosynthesis in Diagram the process of photosynthesis in detail.detail.
http://www.unitedstreaming.com/search/assetDetail.cfm?guidAssetID=083C802D-4438-4FEA-A20C-79909E7CB830
United Streaming video:Photosynthesis (13 min)