Download presentation
Presentation is loading. Please wait.
1
Cellular Respiration
2
powers most cellular work
LE 9-2 Light energy ECOSYSTEM Photosynthesis in chloroplasts CO2 + H2O Organic molecules + O2 Cellular respiration in mitochondria ATP powers most cellular work Heat energy
3
Cellular Respiration
4
Electron transport chain
+ 1/2 O2 2 H + 1/2 O2 (from food via NADH) Controlled release of energy for synthesis of ATP 2 H+ + 2 e– ATP Explosive release of heat and light energy ATP Free energy, G Free energy, G Electron transport chain ATP 2 e– 1/2 O2 2 H+ H2O H2O Uncontrolled reaction Cellular respiration
5
The Stages of Cellular Respiration: A Preview
Cellular respiration has three stages: Glycolysis (breaks down glucose into two molecules of pyruvate) The citric acid cycle (completes the breakdown of glucose) Oxidative phosphorylation (accounts for most of the ATP synthesis) The process that generates most of the ATP is called oxidative phosphorylation because it is powered by redox reactions
6
Substrate-level phosphorylation
Glycolysis Glucose Pyruvate Cytosol Mitochondrion ATP Substrate-level phosphorylation
7
Glycolysis Citric acid cycle Glucose Pyruvate Cytosol Mitochondrion
ATP ATP Substrate-level phosphorylation Substrate-level phosphorylation
8
Electrons carried via NADH Electrons carried via NADH and FADH2
Oxidative phosphorylation: electron transport and chemiosmosis Glycolysis Citric acid cycle Glucose Pyruvate Cytosol Mitochondrion ATP ATP ATP Substrate-level phosphorylation Substrate-level phosphorylation Oxidative phosphorylation
9
Oxidative phosphorylation accounts for almost 90% of the ATP generated by cellular respiration
A small amount of ATP is formed in glycolysis and the citric acid cycle by substrate-level phosphorylation
10
Glycolysis harvests energy by oxidizing glucose to pyruvate
Glycolysis (“splitting of sugar”) breaks down glucose into two molecules of pyruvate Glycolysis occurs in the cytoplasm and has two major phases: Energy investment phase Energy payoff phase
11
Energy investment phase
LE 9-8 Energy investment phase Glucose 2 ADP + 2 P 2 ATP used Glycolysis Citric acid cycle Oxidative phosphorylation Energy payoff phase ATP ATP ATP 4 ADP + 4 P 4 ATP formed 2 NAD+ + 4 e– + 4 H+ 2 NADH + 2 H+ 2 Pyruvate + 2 H2O Net Glucose 2 Pyruvate + 2 H2O 4 ATP formed – 2 ATP used 2 ATP 2 NAD+ + 4 e– + 4 H+ 2 NADH + 2 H+
12
LE 9-9a_1 Glucose ATP Hexokinase ADP Glucose-6-phosphate Glycolysis
Citric acid cycle phosphorylation Oxidation Glucose ATP ATP ATP ATP Hexokinase ADP Glucose-6-phosphate
13
LE 9-9a_2 Glucose ATP Hexokinase ADP Glucose-6-phosphate
Glycolysis Citric acid cycle Oxidation phosphorylation Glucose ATP ATP ATP ATP Hexokinase ADP Glucose-6-phosphate Phosphoglucoisomerase Fructose-6-phosphate ATP Phosphofructokinase ADP Fructose- 1, 6-bisphosphate Aldolase Isomerase Dihydroxyacetone phosphate Glyceraldehyde- 3-phosphate
14
LE 9-9b_1 2 NAD+ Triose phosphate dehydrogenase 2 NADH + 2 H+
1, 3-Bisphosphoglycerate 2 ADP Phosphoglycerokinase 2 ATP 3-Phosphoglycerate Phosphoglyceromutase 2-Phosphoglycerate
15
LE 9-9b_2 2 NAD+ Triose phosphate dehydrogenase 2 NADH + 2 H+
1, 3-Bisphosphoglycerate 2 ADP Phosphoglycerokinase 2 ATP 3-Phosphoglycerate Phosphoglyceromutase 2-Phosphoglycerate Enolase 2 H2O Phosphoenolpyruvate 2 ADP Pyruvate kinase 2 ATP Pyruvate
16
The citric acid cycle completes the energy-yielding oxidation of organic molecules
Before the citric acid cycle can begin, pyruvate must be converted to acetyl CoA, which links the cycle to glycolysis
17
CYTOSOL MITOCHONDRION NAD+ NADH + H+ Acetyl Co A Pyruvate CO2
LE 9-10 CYTOSOL MITOCHONDRION NAD+ NADH + H+ Acetyl Co A Pyruvate CO2 Coenzyme A Transport protein
18
2 molecules per glucose)
Pyruvate (from glycolysis, 2 molecules per glucose) CO2 Glycolysis Citric acid cycle Oxidation phosphorylation NAD+ CoA NADH ATP ATP ATP + H+ Acetyl CoA CoA CoA Citric acid cycle 2 CO2 FADH2 3 NAD+ FAD 3 NADH + 3 H+ ADP + P i ATP
19
The citric acid cycle has eight steps, each catalyzed by a specific enzyme
The acetyl group of acetyl CoA joins the cycle by combining with oxaloacetate, forming citrate The next seven steps decompose the citrate back to oxaloacetate, making the process a cycle The NADH and FADH2 produced by the cycle relay electrons extracted from food to the electron transport chain
20
LE 9-12_1 Acetyl CoA H2O Oxaloacetate Citrate Isocitrate Citric acid
Glycolysis Citric acid cycle Oxidation phosphorylation ATP ATP ATP Acetyl CoA H2O Oxaloacetate Citrate Isocitrate Citric acid cycle
21
LE 9-12_2 Acetyl CoA H2O Oxaloacetate Citrate Isocitrate CO2 Citric
Glycolysis Citric acid cycle Oxidation phosphorylation ATP ATP ATP Acetyl CoA H2O Oxaloacetate Citrate Isocitrate CO2 Citric acid cycle NAD+ NADH + H+ a-Ketoglutarate CO2 NAD+ NADH Succinyl CoA + H+
22
LE 9-12_3 Acetyl CoA H2O Oxaloacetate Citrate Isocitrate CO2 Citric
Glycolysis Citric acid cycle Oxidation phosphorylation ATP ATP ATP Acetyl CoA H2O Oxaloacetate Citrate Isocitrate CO2 Citric acid cycle NAD+ NADH Fumarate + H+ a-Ketoglutarate FADH2 CO2 NAD+ FAD Succinate P NADH i GTP GDP Succinyl CoA + H+ ADP ATP
23
LE 9-12_4 Acetyl CoA NADH + H+ H2O NAD+ Oxaloacetate Malate Citrate
Glycolysis Citric acid cycle Oxidation phosphorylation ATP ATP ATP Acetyl CoA NADH + H+ H2O NAD+ Oxaloacetate Malate Citrate Isocitrate CO2 Citric acid cycle NAD+ H2O NADH Fumarate + H+ a-Ketoglutarate FADH2 CO2 NAD+ FAD Succinate P NADH i GTP GDP Succinyl CoA + H+ ADP ATP
24
During oxidative phosphorylation, chemiosmosis couples electron transport to ATP synthesis
Following glycolysis and the citric acid cycle, NADH and FADH2 account for most of the energy extracted from food These two electron carriers donate electrons to the electron transport chain, which powers ATP synthesis via oxidative phosphorylation
25
The Pathway of Electron Transport
The electron transport chain is in the cristae of the mitochondrion Most of the chain’s components are proteins, which exist in multiprotein complexes The carriers alternate reduced and oxidized states as they accept and donate electrons Electrons drop in free energy as they go down the chain and are finally passed to O2, forming water
26
LE 9-13 NADH 50 FADH2 Multiprotein complexes 40 I FMN FAD Fe•S Fe•S II
Q III Cyt b Oxidative phosphorylation: electron transport and chemiosmosis Glycolysis Citric acid cycle Fe•S 30 Cyt c1 Free energy (G) relative to O2 (kcal/mol) IV Cyt c Cyt a ATP ATP ATP Cyt a3 20 10 2 H+ + 1/2 O2 H2O
27
How many molecules of ATP are created in aerobic respiration – from start to finish?
A. TWO B. FOUR C. THIRTY SIX D. FORTY TWO
28
Net Totals in Energy Production:
Glycolysis = 2 ATP Krebs Cycle = 2 ATP Electron Transport Chain = 32 ATP Total = 36 ATP
29
Energy & Exercise Quick energy – Lactic Acid fermentation is used to get quick energy and gives off lactic acid as a by product, thus the muscle pain. Long-Term Energy – Use oxidative cellular respiration to produce energy. Exercising or activities that last for at least 15 to 20 minutes. Best form for weight control.
30
Comparing Photosynthesis & Respiration
Cellular Respiration Function Energy Storage Energy Release Location Chloroplasts Mitochondria Reactants CO2 and H2O C6H12O6 and O2 Products Equation 6CO2 + 6H2O C6H12O6 + 6O2 C6H12O6 + 6O2 6CO2 + 6H2O
31
Why does it matter?? How is respiration used in the food industry?
How does respiration allow us to do the things that we do? Can Respiration happen without photosynthesis?
32
Ethanol or lactate Citric acid cycle
Glucose CYTOSOL Pyruvate No O2 present Fermentation O2 present Cellular respiration MITOCHONDRION Ethanol or lactate Acetyl CoA Citric acid cycle
33
Your Assignment: Anaerobic respiration is used in the food industry to develop many of the foods we enjoy every day. Choose ONE food produced through fermentation and research how it is made. Write a ½-1 page summary of this process for MONDAY!
Similar presentations
