HonorsHonorsBiologyBiologyCh. 8Ch. 8
HonorsHonorsBiologyBiologyCh. 8Ch. 8
Cellular
EnergyCellular
Energy
CELL
Nucleus
Cytoplasm
Outer membrane and cell surface
I. How Organisms Obtain Energy
I. How Organisms Obtain Energy- Cells are miniature factories where
thousands of reactions using energy occur constantly.
A.Transformation of EnergyA.Transformation of Energy1.First Law of Thermodynamics:
- Energy cannot be created or destroyed,but can be transformed and transferred.
Chemicalenergy
2. Second Law of Thermodynamics:
2. Second Law of Thermodynamics:- When energy is transformed, some
energy is lost as heat.
Heat
CO2
H2O+
3.All Organisms Use Energy
3.All Organisms Use Energya. Autotrophs
- organisms that make their own food- photosynthesis- producers
b. Heterotrophsb. Heterotrophs- organisms that obtain energy from
other organisms- consumers
B. MetabolismB. Metabolism- all the chemical reactions in a cell
1.Catabolic Pathways:- break down large molecules into smaller molecules releasing energy- cellular respiration
2.Anabolic Pathways:- build up larger molecules from small
molecules using energy- photosynthesis
P
Adenosine triphosphate (ATP)
H2O
+ Energy
Inorganic phosphate Adenosine diphosphate (ADP)
PP
P PP i
C. ATPC. ATP- adenosine triphosphate- energy transfer molecule- provides energy for cellular functions
Light Energy
ECOSYSTEM
CO2 + H2O
Photosynthesisin chloroplasts
Cellular respiration
in mitochondria
Organicmolecules
+ O2
ATP
powers most cellular work
Heat Energy
Energy Flow and Chemical Recycling in
Ecosystems
Energy Flow and Chemical Recycling in
Ecosystems
II.Photosynthesis II.Photosynthesis - light energy is converted to chemical energy
A. Chloroplasts- organelle of photosynthesis
B. Photosynthetic Pigments B. Photosynthetic Pigments - Pigments are substances that
absorb light energy
Gammarays X-rays UV Infrared
Micro-waves
Radiowaves
10–5 nm 10–3 nm 1 nm 103 nm 106 nm1 m
106 nm 103 m
380 450 500 550 600 650 700 750 nm
Visible light
Shorter wavelength
Higher energy
Longer wavelength
Lower energy
- chlorophyll absorbs violet-blue and red light
- Chlorophyll a is the primary photosynthetic pigment.
Ab
sorp
tion
of
lig
ht
by
ch
loro
pla
st
pig
men
ts
400 500 600 700
Chlorophyll a
Chlorophyll b
Carotenoids
Wavelength of light (nm)
- Chlorophyll b and carotenoids are accessory pigments.
- Chlorophyll b and carotenoids are accessory pigments.
Phycoerythrin is found in red algaePhycoerythrin is found in red algae
Phycocyanin is found in blue-green algae
Phycocyanin is found in blue-green algae
Chlorophyll a, Chlorophyll b, and β - Carotene are found in plants.
Chlorophyll a, Chlorophyll b, and β - Carotene are found in plants.
Chlorophyll bChlorophyll bChlorophyll bChlorophyll bChlorophyll aChlorophyll aChlorophyll aChlorophyll a XanthophyXanthophyllll
XanthophyXanthophyllll
ββ --
CaroteneCaroteneββ --
CaroteneCarotene
Photosynthetic Pigments Found in
Spinach leaves
Photosynthetic Pigments Found in
Spinach leaves
Molecular Structure of Cellulose
Molecular Structure of Cellulose
C. Light Reactions C. Light Reactions - Light energy is used to produce
ATP and NADPH for the Calvin Cycle.
O2
CO2H2O
Light
Light reactions Calvin cycle
NADP+
ADP
ATP
NADPH
+ P 1
RuBP 3-Phosphoglycerate
Amino acidsFatty acids
Starch(storage)
Glucose
G3P
Photosystem IIElectron transport chain
Photosystem I
Chloroplast
STROMA(Low H+ concentration)
Photosystem IICytochrome
complex
H2O O21⁄2
Photosystem ILight
THYLAKOID SPACE(High H+ concentration)
STROMA(Low H+ concentration)
Thylakoidmembrane
ATPsynthase
PqPc
Fd
NADP+
reductase
NADPH + H+
NADP+ + 2H+
ToCalvincycle
ADP
PATP
H+
2 H++2 H+
2 H+
- Light energy is used to produce ATP and NADPH for the Calvin Cycle.
C. Light Reactions C. Light Reactions
P700
+
Photosystem II
e
Primary acceptor
2 H+
1⁄2
H2O
e
e
En
erg
y o
f e
lec
tro
ns
Pq
Cytochromecomplex
Pc
ATP
Electron transport chain
Primary acceptor
e
Photosystem I
LightLight
Fd
Electron
Transportchain
NADP+
reductaseNADPH
NADP+
+ 2 H+
+ H+
P680
O2
e
e
1. Light absorbed by Photosystem II
1. Light absorbed by Photosystem II - Water molecules are split, oxygen
released.- Electron becomes ‘excited’ and enters
electron transport chain.
2. The Electron Transport Chain 2. The Electron Transport Chain
- Energy from electrons ‘pumps’ H+ into thylakoid space as it passes along the
electron transport chain.
P700
+
Photosystem II
e
Primary acceptor
2 H+
1⁄2
H2O
e
e
En
erg
y o
f e
lec
tro
ns
Pq
Cytochromecomplex
Pc
ATP
Electron transport chain
Primary acceptor
e
Photosystem I
LightLight
Fd
Electron
Transportchain
NADP+
reductaseNADPH
NADP+
+ 2 H+
+ H+
P680
O2
e
e
3. More Light Absorbed by
Photosystem I3. More Light Absorbed by
Photosystem I
- Electron becomes ‘re-excited’.- NADPH (an electron carrier and energy
transport molecule) is formed.
P700
+
Photosystem II
e
Primary acceptor
2 H+
1⁄2
H2O
e
e
En
erg
y o
f e
lec
tro
ns
Pq
Cytochromecomplex
Pc
ATP
Electron transport chain
Primary acceptor
e
Photosystem I
LightLight
Fd
Electron
Transportchain
NADP+
reductaseNADPH
NADP+
+ 2 H+
+ H+
P680
O2
e
e
STROMA(Low H+ concentration)
Photosystem IICytochrome
complex
H2O O21⁄2
Photosystem ILight
THYLAKOID SPACE(High H+ concentration)
STROMA(Low H+ concentration)
Thylakoidmembrane
ATPsynthase
PqPc
Fd
NADP+
reductase
NADPH + H+
NADP+ + 2H+
ToCalvincycle
ADP
PATP
H+
2 H++2 H+
2 H+
4. Chemiosmosis 4. Chemiosmosis - Hydrogen ions (protons) move down
their concentration gradient out of the thylakoid space.
5. ATP Synthase 5. ATP Synthase
- ATP synthesized by ATP synthase as hydrogen ions pass out of the thylakoid space.
STROMA
THYLAKOID SPACE
H+
H+
H+
H+
H+
H+ H+
H+
P i
+
ADP
ATP
A rotor within the membrane spins clockwise whenH+ flows pastit down the H+
gradient.A stator anchoredin the membraneholds the knobstationary.
A rod (or “stalk”)extending into the knob alsospins, activatingcatalytic sites inthe knob.
Three catalytic sites in the stationary knobjoin inorganic Phosphate to ADPto make ATP.
D.Calvin Cycle D.Calvin Cycle - Glucose produced with energy
from ATP and NADPH from the light reactions.
1. Carbon Fixation 1. Carbon Fixation
- 6 CO2 are joined to 6 5-C molecules of RuBP to form 12 3-C molecules of PGA.
The Calvin Cycle
The Calvin Cycle
LightH2O CO2
LIGHTREACTIONS
ATP
NADPH
NADP+
[CH2O] (sugar)
CALVINCYCLE
ADP
(Entering oneat a time)CO2
3
Phase 1: Carbon fixation
Rubisco
Short-livedintermediate
3 P P
3 P P
Ribulose bisphosphate(RuBP)
P
3-Phosphoglycerate6 ATP
6 ADP
Input
CALVINCYCLE
O2
6
2. G3P Produced 2. G3P Produced
- Energy from 12 ATP and 12 NADPH is used to produce 12 G3P (glyceraldehyde 3-phosphate) molecules.
- 2 G3P molecules are used to make glucose.
(Entering oneat a time)CO2
3
Phase 1: Carbon fixation
Rubisco
Short-livedintermediate
3 P P
3 P P
Ribulose bisphosphate(RuBP)
P
3-Phosphoglycerate
P6 P
1,3-Bisphosphoglycerate
6 NADPH
6 NADP+
6 P i
P6
Glyceraldehyde-3-phosphate(G3P)
Phase 2:Reduction
6 ATP
CALVINCYCLE
P1
G3P(a sugar)Output
Glucose andother organiccompounds
6 ADP
InputLightH2O CO2
LIGHTREACTIONS
ATP
NADP+
[CH2O] (sugar)
CALVINCYCLE
NADPH
ADP
O2
6
The Calvin Cycle
The Calvin Cycle
3. Calvin Cycle Completed 3. Calvin Cycle Completed
- 6 RuBP molecules produced from 10 G3P molecules to complete the Calvin Cycle.
(Entering oneat a time)CO2
3
Phase 1: Carbon fixation
Rubisco
Short-livedintermediate
3 P P
3 P P
Ribulose bisphosphate(RuBP)
P
3-Phosphoglycerate
P6 P
1,3-Bisphosphoglycerate
6 NADPH
6 NADP+
6 P i
P6
Glyceraldehyde-3-phosphate(G3P)
Phase 2:Reduction
6 ATP
3 ATP
3 ADP CALVINCYCLE
P5
Phase 3:Regeneration ofthe CO2 acceptor(RuBP)
P1
G3P(a sugar)Output
Glucose andother organiccompounds
G3P
6 ADP
LightH2O CO2
LIGHTREACTIONS
NADPH
NADP+
[CH2O] (sugar)
CALVINCYCLE
Input
ATP
ADP
O2
6
The Calvin Cycle
The Calvin Cycle
Alternative Photosynthesis Pathways:
C4 and CAMAlternative Photosynthesis Pathways:
C4 and CAM
Organic acidsrelease CO2 toCalvin cycle
Spatial separation of steps. In C4 plants, carbon fixation and the Calvin cycle occur in different types of cells.
Temporal separation of steps. In CAM plants, carbon fixation and the Calvin cycle occur in the same cells at different times.
PineappleSugarcane
Bundle-sheath
cell
Mesophyll Cell
Organic acid
CALVINCYCLE
Sugar
CO2 CO2
Organic acid
CALVINCYCLE
Sugar
C4 CAM
CO2 incorporatedinto four-carbon
organic acids(carbon fixation)
Night
Day
1
2 Organic acidsrelease CO2 toCalvin cycle
CO2
C4
Photosynthesis
C4
Photosynthesis
CAM Photosynthe
sis
CAM Photosynthe
sis
III. Cellular Respiration III. Cellular Respiration - Organic molecules (glucose) are broken
down to release energy in the form of ATP to do cellular work.
Intermembrane
Space
ATP Synthase
Inner Membrane
Outer MembraneDNA
RibosomeCrista
e
Matrix
Granules
MitochondrionMitochondrion
- Occurs in 2 main parts: glycolysis and aerobic respiration
Electrons
carriedvia
NADH
Glycolysis
Glucose Pyruvate
ATP
Electrons carried via NADH and
FADH2
Kreb’s Cycle
Electron Transportand
Chemiosmosis
ATPATP
MitochondrionAerobic
Respiration
A. Glycolysis A. Glycolysis - splits glucose (6-C) into
pyruvate (3-C) to release energy
- produces 2 ATP and 2 NADH- occurs in the cytoplasm - does not require oxygen
2 ADP + 2 P i 2 ATP
GlycolysisGlucose
2 NAD+ 2 NADH
2 Pyruvate
O–
OC
C O
CH3
ATP
NAD+
2 CO2
3 NAD+
3 NADH
+ 3 H+
ADP + P i
FAD
FADH2
Kreb’sCycle
CoA
CoA Acetyle CoA
NADH+ H+
CoA
CO2
Pyruvate
- completes the energy yielding break down of pyruvate
- produces (for each glucose) 2 ATP, 6 NADH, 2 FADH2, and 3 CO2
- takes place in the matrix of the mitochondrion
B. Krebs Cycle B. Krebs Cycle
Electron Transportand Chemiosmosis
Glycolysis
ATP ATP ATP
H+
H+H+
H+
H+
ATPP i
Protein complexof electron carners
Cyt c
(Carrying electronsfrom food)
NADH+
FADH2
NAD+
FAD+ 2 H+ + 1/2 O2
H2O
ADP +
Electron Transport ChainElectron transport and pumping of H+,
which create an H+ gradient across the membrane
ChemiosmosisATP synthesis powered by the flow of H+ back across the membrane
ATPsynthase
Q
Intermembranespace
Innermitochondrialmembrane
Mitochondrialmatrix
Kreb’sCycle
C. Electron Transport Chain C. Electron Transport Chain - a series of protein molecules embedded in
the inner membrane of the mitochondrion- requires oxygen
- Energy from electrons from NADH and FADH2 pumps H+ ion into the intermembrane space creating a H+ gradient.
Electron Transportand Chemiosmosis
Glycolysis
ATP ATP ATP
H+
H+H+
H+
H+
ATPP i
Protein complexof electron carners
Cyt c
(Carrying electronsfrom food)
NADH+
FADH2
NAD+
FAD+ 2 H+ + 1/2 O2
H2O
ADP +
Electron Transport ChainElectron transport and pumping of H+,
which create an H+ gradient across the membrane
ChemiosmosisATP synthesis powered by the flow of H+ back across the membrane
ATPsynthase
Q
Intermembranespace
Innermitochondrialmembrane
Mitochondrialmatrix
Kreb’sCycle
- At the end of the chain, electrons are passed to oxygen, forming water.
Electron Transportand Chemiosmosis
Glycolysis
ATP ATP ATP
H+
H+H+
H+
H+
ATPP i
Protein complexof electron carners
Cyt c
(Carrying electronsfrom food)
NADH+
FADH2
NAD+
FAD+ 2 H+ + 1/2 O2
H2O
ADP +
Electron Transport ChainElectron transport and pumping of H+,
which create an H+ gradient across the membrane
ChemiosmosisATP synthesis powered by the flow of H+ back across the membrane
ATPsynthase
Q
Intermembranespace
Innermitochondrialmembrane
Mitochondrialmatrix
Kreb’sCycle
D. Chemiosmosis D. Chemiosmosis - H+ ions move down their concentration
gradient out of the intermembrane space.- ATP synthesized by
ATP Synthase as H+ ions pass
out of the intermembrane
space.
MITOCHONDRIAL MATRIX
INTERMEMBRANE SPACE
H+
H+
H+
H+
H+
H+ H+
H+
P i
+ADP
ATP
A rotor within the membrane spins clockwise whenH+ flows pastit down the H+
gradient.
A stator anchoredin the membraneholds the knobstationary.
A rod (or “stalk”)extending into the knob alsospins, activatingcatalytic sites inthe knob.
Three catalytic sites in the stationary knobjoin inorganic Phosphate to ADPto make ATP.
ATP Synthase
ATP Synthase
D. Chemiosmosis D. Chemiosmosis - H+ ions move down their concentration
gradient out of the intermembrane space.- ATP synthesized by
ATP Synthase as H+ ions pass
out of the intermembrane
space.- Produces 32 ATP
ATP Synthase
ATP Synthase
IV. Anaerobic Respiration (Fermentation)
IV. Anaerobic Respiration (Fermentation)- Uses glycolysis to produce ATP in the
absence of O2.
- Regenerates NAD from NADH. - Produces only 2 ATP from glucose.
Glucose
CYTOSOLPyruvate
No O2 present:Fermentation
O2 present: Cellular Respiration
Ethanolor
Lactate
Acetyl CoAMITOCHONDRION
Kreb’scycle
A. Lactic Acid FermentationA. Lactic Acid Fermentation- Occurs when skeletal muscles use up O2
faster than lungs can supply O2.
- Lactic acid produced from pyruvate and NADH converted to NAD.
2 ADP + 2 P i 2 ATP
GlycolysisGlucose
2 NAD+ 2 NADH
2 Lactate
Lactic acid fermentation
O–
C O
C O
CH3O
C O
C OHH
CH3
2 Pyruvate
Usain Bolt
- Also produced by bacteria when processing milk into yogurt and cheese.
B.Alcohol FermentationB.Alcohol Fermentation- Occurs in yeast and some bacteria.- Ethanol and CO2 produced
from pyruvate and NADH converted to NAD.
2 ADP + 2 P i 2 ATP
GlycolysisGlucose
2 NAD+ 2 NADH
2 Pyruvate
2 Acetaldehyde2 Ethanol
Alcohol fermentation
H
H OH
CH3
C
O–
OC
C O
CH3
H
C O
CH3
CO22 +2 H+
How Cells Obtain EnergyA Review of Cellular Respiration and Photosynthesis
(14:02)
The
End
The
End
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