respiration. how is a marathoner different from a sprinter? aerobic vs. anaerobic
TRANSCRIPT
Respiration
How Is a Marathoner Different from a Sprinter?
Aerobic vs. anaerobic
Aerobic vs. Anaerobic
Aerobic pathways
• Newer• Require O• Start in cytoplasm• Completed in
mitochondria
Anaerobic pathways
• Older• No O• In cytoplasm
Food Sources
• Autotrophs (producers)
• Hetrotrophs (consumers)
• Both make ATP
CO2
H2O
Glucose
O2
ATP
ECOSYSTEM
Sunlight energy
Photosynthesis in chloroplasts
Cellular respiration in mitochondria
(for cellular work)
Heat energy
Energy Consumption
Why Breathe?
CO2
CO2
O2
O2Bloodstream
Muscle cells carrying out
Cellular Respiration
Breathing
Glucose O2
CO2 H2O ATP
Lungs
Summary Equation for Aerobic Respiration
C6H12O6CO26 H2O ATPs
Glucose Oxygen gas Carbon dioxide
6
Water Energy
O2 6+ + +
Electron Transfers
• Oxidation - lose electron
• Reduction - gain electron
C6H12O6 6 O2 6 CO2 6 H2O
Loss of hydrogen atoms (oxidation)
Gain of hydrogen atoms (reduction)
Energy
(ATP)Glucose
+ + +
Coenzymes
• NAD+ and FAD
• NADH and FADH2
• Carry electrons and hydrogen
Coenzymes
OH H O 2H
Reduction
Dehydrogenase
(carries2 electrons)
NAD 2H
2H 2e
NADH H
Oxidation
+
+
+
+
ETC
H2O
NAD
NADH
ATP
H
H
Controlled release of energy for
synthesis of ATP
Electron transport chain
2 O2
2e
2e
1
2
NADH
NADH FADH2
GLYCOLYSIS
Glucose Pyruvate CITRIC ACID CYCLE
OXIDATIVE PHOSPHORYLATION
(Electron Transport and Chemiosmosis)
Substrate-level phosphorylation
Oxidative phosphorylation
Mitochondrion
and
High-energy electrons
carried by NADH
ATPATPATP
CO2 CO2
Cytoplasm
Substrate-level phosphorylation
Figure 6.6
Overview
• C6H12O6
Glucose
In-text figurePage 136
Glycolysis
Glycolysis
• Two stages
• Energy-requiring steps
– 2 ATP
– Transfers P group
• Energy-releasing steps
– Splits activated glucose
– Forms 2 pyruvate, 4 ATP and 2 NADH
Glycolysis
NAD NADH H
Glucose2 Pyruvate
ATP2P2 ADP
22
2
2
+
+
Figure 6.8_1
Figure 6.8_2
Figure 6.8_3
“Prep” Reaction
Pyruvate is oxidized • 2 C acetyl-CoA
• 3rd C released as CO2
• NAD+ -> NADH
“Prep” Reaction
CO2
Pyruvate
NAD NADH H
CoA
Acetyl CoA(acetyl coenzyme A)
Coenzyme A
Figure 6.8
Citric Acid Cycle
CoACoA
CO2
NAD
NADHFAD
FADH2
ATP P
CITRIC ACID CYCLE
ADP
3
3
3 H
Acetyl CoA
2
Citric Acid Cycle
• Loads e- and H onto NAD+ and FAD
• ATP by substrate-level Phos.
•1 turn yields:– 2 CO2
– 1 ATP,
– 3 NADH
– 1 FADH2
– Regenerates starting product
Citric Acid Cycle
and Steps and
CITRIC ACID CYCLE
Oxaloacetate
CoA
CoA
2 carbons enter cycle
Acetyl CoA
Citrate
leaves cycle
H
NAD
NADH
CO2
Alpha-ketoglutarate
leaves cycleCO2
ADP P
NAD
NADH H
ATP
Succinate
FAD
FADH2
Malate
H
NAD
NADH
Step
Acetyl CoA stokes the furnace.
Steps
NADH, ATP, and CO2 are generated during redox reactions.
Redox reactions generate FADH2 and NADH.
Electron Transport
• Coenzymes deliver electrons• Pump H+ • Forms H+ gradient• H+ flows down gradient• Powers ATP formation (ATP
synthase)
Figure 6.12a
Importance of Oxygen
Intermembrane space
Inner mitochondrial membrane
Mitochondrial matrix
Protein complex
Electron flow
Electron carrier
NADH NAD+
FADH2 FAD
H2OATPADP
ATP synthase
H+ H+ H+
H+
H+H+
H+
H+
H+
H+
H+
H+
H+
H+
P
O2
Electron Transport Chain Chemiosmosis
.
OXIDATIVE PHOSPHORYLATION
+ 212
Figure 6.10
Summary of Energy Harvest
(per molecule of glucose)• Glycolysis
– 2 ATP
• Citric acid and “prep” rxns– 2 ATP
• ETC
– 32 ATP formed
• 686 kcal of energy are released
• 7.5 kcal are conserved in each ATP
• When 36 ATP form, 270 kcal (36 X 7.5) are
captured in ATP
• Efficiency is 270 / 686 X 100 = 39 percent
• Most energy is lost as heat
FYI - Efficiency of Aerobic Respiration
Poisons•Block the movement of electrons (cyanide, CO)
•Block the flow of H+ through ATP synthase (Oligomycin)
H+
H+
H+
H+
H+
H+ H+ H+ H+
H+
H+
H+H+
O2
H2OP ATP
NADH NAD+
FADH2 FAD
Rotenone Cyanide, carbon monoxide
Oligomycin
DNP
ATPSynthase
2
ADP
Electron Transport Chain Chemiosmosis
12
Figure 6.11
Anaerobic Pathways
• Less ATP
• Fermentation pathways
Fermentation Pathways
• Bacteria – Lactobacillus (cheese)
• Animal cells
Fermentation Pathways
• Glycolysis
• 2 ATP
• Regenerate NAD+
Lactate Fermentation
• Muscle cells FAST ATP • Lactic acid builds up
2 Lactate
NAD NADH NADH NAD2 2 22
2 ATP2 ADP 22 Pyruvate
GLYCOLYSIS
P
Glucose
Alcoholic Fermentation• Produces ethanol• Yeast
NAD NADH NADH NAD2 2 2 2
GLYCOLYSIS
2 ADP 2 P ATP
Glucose 2 Pyruvate
releasedCO2
2 Ethanol
22
Figure 6.13B
Figure 6.16
Question of the Day
How does the insecticide rotenone work? Is it safe?