Biology January 26, 2015 Copy and answer the following EQ into your science journal. EQ: How does...
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Transcript of Biology January 26, 2015 Copy and answer the following EQ into your science journal. EQ: How does...
BiologyJanuary 26, 2015
Copy and answer the following EQ into your science journal.
EQ: How does the process of photosynthesis relate
to me?
Word of the DaySTOMATA
A microscopic pore on the
surface (epidermis)
of land plants
Diagrams
Draw, color and label the following diagrams into your science journal: Figure 8-4 page 206Figure 8-6 page 208Figure 8-7 page 209Figure 8-10 page 211
PHOTOSYNTHESISPHOTOSYNTHESIS
5
PhotosynthesisPhotosynthesis
• AnabolicAnabolic (small molecules combined) (small molecules combined)• EndergonicEndergonic (stores energy) (stores energy)• Carbon dioxide (COCarbon dioxide (CO22)) requiring process requiring process
that uses that uses light energy (photons)light energy (photons) and and water (Hwater (H22O)O) to produce to produce organic organic macromolecules (glucose).macromolecules (glucose).
6CO2 + 6H2O C6H12O6 + 6O2glucoseglucose
SUNphotonsphotons
6
Question:Question:
Where does Where does photosynthesis photosynthesis
take place?take place?
7
PlantsPlants• Autotrophs Autotrophs – produce their own food – produce their own food
(glucose)(glucose)
• Process called Process called photosynthesisphotosynthesis
• Mainly occurs in the Mainly occurs in the leaves:leaves:
a.a. stoma - poresstoma - pores
b.b. mesophyll cellsmesophyll cells
StomaMesophyllCell
Chloroplast
8
Stomata (stoma)Stomata (stoma)PoresPores in a plant’s cuticle through in a plant’s cuticle through
which which water vaporwater vapor and and gasesgases (CO(CO22
& O& O22)) are exchanged between the are exchanged between the
plant and the atmosphere.plant and the atmosphere.
Guard CellGuard CellCarbon Dioxide (CO2)
Oxygen (O2)
Found on the underside of leavesFound on the underside of leaves
StomaStoma
9
Mesophyll Cell of LeafMesophyll Cell of Leaf
Cell Wall
NucleusNucleus
Chloroplast
Central Vacuole
Photosynthesis occurs in these cells!Photosynthesis occurs in these cells!
10
ChloroplastChloroplast
OrganelleOrganelle where photosynthesisphotosynthesis takes place.
GranumThylakoid
Stroma
Outer Membrane
Inner Membrane
Thylakoid stacks are connected togetherThylakoid stacks are connected together
11
ThylakoidThylakoid
Thylakoid Membrane
Thylakoid SpaceGranum
Grana make up the inner membraneGrana make up the inner membrane
12
Question:Question:
Why are Why are plants plants green?green?
13
Chlorophyll MoleculesChlorophyll Molecules
• Located in the Located in the thylakoid membranesthylakoid membranes• Chlorophyll have Chlorophyll have MgMg++ in the center in the center• Chlorophyll pigments Chlorophyll pigments harvest energy harvest energy
(photons)(photons) by absorbing certain by absorbing certain wavelengths wavelengths (blue-420 nm and red-(blue-420 nm and red-660 nm660 nm are most important) are most important)
• Plants are Plants are greengreen because the because the green green wavelength is reflectedwavelength is reflected, not absorbed, not absorbed.
14
15
Wavelength of Light (nm)Wavelength of Light (nm)
400 500 600 700
Short wave Long wave(more energy) (less energy)
16
Absorption of Light by Absorption of Light by ChlorophyllChlorophyll
wavelengthwavelength
Absorption
violet blue green yellow orange red
Chlorophyll absorbs blue-violet & red light bestChlorophyll absorbs blue-violet & red light best
17
Question:Question:
During the fall, During the fall, what causes the what causes the leaves to change leaves to change
colors?colors?
18
Fall ColorsFall Colors
• In addition to the chlorophyll In addition to the chlorophyll pigments, there are pigments, there are other pigmentsother pigments presentpresent
• During the fall, the During the fall, the green green chlorophyll pigments are greatly chlorophyll pigments are greatly reducedreduced revealing the other revealing the other pigmentspigments
• CarotenoidsCarotenoids are pigments that are are pigments that are either either redred, , orangeorange, or , or yellowyellow
19
Redox ReactionRedox Reaction
The The transfertransfer of one or more of one or more electronselectrons from one reactant to from one reactant to anotheranother
Two types:Two types:
1.1. Oxidation is the Oxidation is the lossloss of e of e--
2.2. Reduction is the Reduction is the gaingain of e of e--
20
Oxidation ReactionOxidation Reaction
The The loss of electronsloss of electrons from a from a substance or the substance or the gain of gain of oxygen.oxygen.
glucoseglucose
6CO2 + 6H2O C6H12O6 + 6O2
OxidationOxidation
Carbon Carbon dioxidedioxide WaterWater
OxygenOxygen
21
Reduction ReactionReduction Reaction
The The gain of electronsgain of electrons to a to a substance or the substance or the loss of loss of oxygen.oxygen.
glucoseglucose
6CO2 + 6H2O C6H12O6 + 6O2
ReductionReduction
22
Question:Question:
Why do cells Why do cells use for use for energy?energy?
23
Energy for Life on EarthEnergy for Life on Earth
• Sunlight is the ULTIMATE energy for all life on Earth
• Plants store energy in the chemical bonds of sugars
• Chemical energy is released as ATP during cellular respiration
24
Structure of ATPStructure of ATP
• ATP stands for adenosine triphosphate
• It is composed of the nitrogen base ADENINE, the pentose (5C) sugar RIBOSE, and three PHOSPHATE groups
• The LAST phosphate group is bonded with a HIGH ENERGY chemical bond
• This bond can be BROKEN to release ENERGY for CELLS to use
25
Removing a Phosphate Removing a Phosphate from ATPfrom ATP
Breaking the LAST PHOSPHATE bond from ATP, will ---– Release ENERGY for cells to use– Form ADP– Produce a FREE PHOSPHATE
GROUP
26
High Energy Phosphate BondHigh Energy Phosphate Bond
27
FREE PHOSPHATE can be re-FREE PHOSPHATE can be re-attached to ADP reforming ATPattached to ADP reforming ATP
Process called Process called PhosphorylationPhosphorylation
28
PhosphorylationPhosphorylation
29
Parts of Parts of PhotosynthesisPhotosynthesis
30
Two Parts of Two Parts of PhotosynthesisPhotosynthesis
Two reactions make up Two reactions make up photosynthesis:photosynthesis:
1.1.Light Reaction or Light Light Reaction or Light Dependent ReactionDependent Reaction - -
Produces energy from solar Produces energy from solar power (photons) in the form of power (photons) in the form of ATP and NADPH.ATP and NADPH.
SUNSUN
31
Two Parts of Two Parts of PhotosynthesisPhotosynthesis
2. 2. Calvin Cycle or Light Calvin Cycle or Light Independent Reaction Independent Reaction
• Also called Also called Carbon FixationCarbon Fixation or or CC33 Fixation Fixation
• Uses energy (Uses energy (ATP and ATP and NADPHNADPH) from light reaction to ) from light reaction to make sugar make sugar (glucose).(glucose).
32
Light Reaction Light Reaction (Electron Flow)(Electron Flow)
• Occurs in the Occurs in the Thylakoid Thylakoid membranesmembranes
• During the During the light reactionlight reaction, there , there are are twotwo possible routes for possible routes for electron flow:electron flow:
A.A. Cyclic Electron FlowCyclic Electron Flow
B.B. Noncyclic Electron FlowNoncyclic Electron Flow
33
Cyclic Electron FlowCyclic Electron Flow
• Occurs in the Occurs in the thylakoidthylakoid membrane. membrane.
• Uses Uses Photosystem I onlyPhotosystem I only
• P700P700 reaction center- chlorophyll a reaction center- chlorophyll a
• Uses Electron Transport Chain Uses Electron Transport Chain (ETC)(ETC)
• Generates Generates ATP onlyATP only
ADP + ADP + ATP ATPP
34
Cyclic Electron FlowCyclic Electron Flow
P700
PrimaryElectronAcceptor
e-
e-
e-
e-
ATPATPproducedby ETC
Photosystem I
AccessoryPigments
SUN
Photons
Pigments absorb light energy & excite e- of Pigments absorb light energy & excite e- of Chlorophyll a to produce ATP Chlorophyll a to produce ATP
35
Noncyclic Electron FlowNoncyclic Electron Flow• Occurs in the Occurs in the thylakoidthylakoid membrane membrane• Uses Uses Photosystem II Photosystem II and and
Photosystem IPhotosystem I• P680 P680 reaction center reaction center (PSII)(PSII) - -
chlorophyll achlorophyll a• P700P700 reaction center reaction center (PS I)(PS I) - -
chlorophyll achlorophyll a• Uses Electron Transport Chain Uses Electron Transport Chain
(ETC)(ETC)• Generates Generates OO22, ATP and NADPH, ATP and NADPH
36
Noncyclic Electron FlowNoncyclic Electron Flow
P700
Photosystem IP680
Photosystem II
PrimaryElectronAcceptor
PrimaryElectronAcceptor
ETC
EnzymeReaction
H2O
1/2O1/2O22 + 2H+
ATPATP
NADPHNADPH
Photon
2e-
2e-
2e-
2e-
2e-
SUN
Photon
HH22O is split in PSII & ATP is made, while the energy carrier NADPH is O is split in PSII & ATP is made, while the energy carrier NADPH is
made in PSImade in PSI
37
Noncyclic Electron FlowNoncyclic Electron Flow
• ADP +ADP + ATPATP
• NADPNADP++ + H + H NADPHNADPH
• OxygenOxygen comes from the splitting comes from the splitting of Hof H22O, not COO, not CO22
HH22O O 1/2 O 1/2 O22 + 2H + 2H++
PP
38
ChemiosmosisChemiosmosis
• Powers Powers ATP synthesisATP synthesis
• Takes place across the thylakoid Takes place across the thylakoid membranemembrane
• Uses Uses ETCETC and and ATP synthase ATP synthase (enzyme)(enzyme)
• H+H+ move down their move down their concentration gradient through concentration gradient through channels of ATP synthasechannels of ATP synthase forming forming ATP from ADPATP from ADP
39
ChemiosmosisChemiosmosisH+ H+
ATP Synthase
H+ H+ H+ H+
H+ H+ high Hhigh H++
concentrationconcentration
H+ADP + P ATP
PS II PS IE
TC
low Hlow H++
concentrationconcentration
H+ThylakoidThylakoidSpaceSpace
ThylakoidThylakoid
SUN (Proton Pumping)
40
Calvin CycleCalvin Cycle• Carbon Fixation Carbon Fixation (light independent (light independent
reaction)reaction)• CC33 plants (80% of plants on earth) plants (80% of plants on earth)• Occurs in the Occurs in the stromastroma• Uses Uses ATP and NADPHATP and NADPH from light from light
reaction as energyreaction as energy• Uses Uses COCO22
• To produce To produce glucoseglucose: it takes : it takes 6 turns 6 turns and uses 18 ATP and 12 NADPH. and uses 18 ATP and 12 NADPH.
41
ChloroplastChloroplast
GranumThylakoid
STROMA– where Calvin Cycle occursOuter Membrane
Inner Membrane
42
Calvin Cycle (CCalvin Cycle (C33 fixation) fixation)
6CO2
6C-C-C-C-C-C
6C-C-C 6C-C-C
6C-C-C-C-C
12PGA
RuBP
12G3P
(unstable)
6NADPH 6NADPH
6ATP 6ATP
6ATP
C-C-C-C-C-CGlucose
(6C)(36C)
(36C)
(36C)
(30C)
(30C)
(6C)
6C-C-C 6C-C-C
C3
glucose
43
Calvin CycleCalvin Cycle
Remember: CRemember: C33 = Calvin Cycle = Calvin Cycle
C3
Glucose
44
PhotorespirationPhotorespiration
• Occurs on hot, dry, bright daysOccurs on hot, dry, bright days
• Stomates closeStomates close
• Fixation of OFixation of O22 instead of CO instead of CO22
• Produces Produces 2-C molecules 2-C molecules instead of 3-C sugar moleculesinstead of 3-C sugar molecules
• Produces Produces no sugarno sugar molecules molecules or or no ATPno ATP
45
PhotorespirationPhotorespiration
Because of photorespiration, plants Because of photorespiration, plants have special adaptations to limit the have special adaptations to limit the effect of photorespiration:effect of photorespiration:
1.1. CC44 plants plants
2.2. CAM plantsCAM plants
46
CC44 Plants Plants
• Hot, moist Hot, moist environmentsenvironments
• 15% of plants 15% of plants ((grasses, corn, grasses, corn, sugarcane)sugarcane)
• Photosynthesis Photosynthesis occurs in 2 placesoccurs in 2 places
• Light reactionLight reaction - - mesophyll cellsmesophyll cells
• Calvin cycleCalvin cycle - - bundle sheath cellsbundle sheath cells
47
CC44 Plants Plants
Mesophyll CellMesophyll Cell
CO2
C-C-C
PEP
C-C-C-CMalate-4C sugar
ATP
Bundle Sheath CellBundle Sheath Cell
C-C-C
Pyruvic Acid
C-C-C-C
CO2
C3
Malate
Transported
glucoseVascular Tissue
48
CAM PlantsCAM Plants
• Hot, dry environmentsHot, dry environments• 5%5% of plants (cactus and ice of plants (cactus and ice
plants)plants)• Stomates closed during dayStomates closed during day• Stomates open during the nightStomates open during the night• Light reaction - occurs during the Light reaction - occurs during the
dayday• Calvin Cycle - occurs when COCalvin Cycle - occurs when CO22 is is
presentpresent
49
CAM PlantsCAM PlantsNight (Stomates Open) Day (Stomates Closed)
Vacuole
C-C-C-CMalate
C-C-C-CMalate Malate
C-C-C-CCO2
CO2
C3
C-C-CPyruvic acid
ATPC-C-CPEP glucose
50
Question:Question:
Why do CAM Why do CAM plants close their plants close their stomata during stomata during
the day?the day?
Cam plants close Cam plants close their stomata in their stomata in the hottest part the hottest part
of the day to of the day to conserve waterconserve water