28
Chapter 9 Cellular Respiration

Chapter 9 Cellular Respiration. I.Catabolic Pathways Yield Energy A.Cellular Respiration 1.C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O 2.Exergonic 3.ATP production

Embed Size (px)

Citation preview

Page 1: Chapter 9 Cellular Respiration. I.Catabolic Pathways Yield Energy A.Cellular Respiration 1.C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O 2.Exergonic 3.ATP production

Chapter 9

Cellular Respiration

Page 2: Chapter 9 Cellular Respiration. I.Catabolic Pathways Yield Energy A.Cellular Respiration 1.C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O 2.Exergonic 3.ATP production

I. Catabolic Pathways Yield Energy

A. Cellular Respiration1. C6H12O6 + 6O2 6CO2 + 6H2O

2. Exergonic

3. ATP production is the benefit for the cell

Page 3: Chapter 9 Cellular Respiration. I.Catabolic Pathways Yield Energy A.Cellular Respiration 1.C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O 2.Exergonic 3.ATP production

B. Redox Reactions: Transfer electrons from one reactant to another reactant

1. Oxidation: Substance loses electrons (Na)

2. Reduction: Substance gains electrons (Cl)

3. Electronegativity: An atoms ability to attract electrons to itself (Cl)

4. Energy is released when an electron changes location.

Page 4: Chapter 9 Cellular Respiration. I.Catabolic Pathways Yield Energy A.Cellular Respiration 1.C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O 2.Exergonic 3.ATP production

C. Redox Reactions when electrons are shared.

1. Some redox reactions change the degree to which electrons are shared.

2. Methane Example

CH4

H

H

HH CO O O O OC

H H

Methane(reducingagent)

Oxygen(oxidizingagent)

Carbon dioxide Water

+ 2O2 CO2 + Energy + 2 H2O

becomes oxidized

becomes reduced

Reactants Products

Figure 9.3

Page 5: Chapter 9 Cellular Respiration. I.Catabolic Pathways Yield Energy A.Cellular Respiration 1.C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O 2.Exergonic 3.ATP production

3. Cellular respiration is similar.a) C6H12O6 + 6O2 6CO2 + 6H2O

b) Hydrogens are transferred to Oxygen

c) More importantly, hydrogen’s electrons move away from it and closer to oxygen

d) Much energy is released in this motion

Page 6: Chapter 9 Cellular Respiration. I.Catabolic Pathways Yield Energy A.Cellular Respiration 1.C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O 2.Exergonic 3.ATP production

D. NAD+ and Energy harvest from e-

1. Hydrogen does not immediately join Oxygen to form water. (C6H12O6 + O2 CO2 H2O)

2. NAD+: (Nicotinamide adenine dinucleotide)a) Allows e- energy to be harvested slowly.

(a) Uncontrolled reaction

Fre

e en

ergy

, G

H2O

Explosiverelease of

heat and lightenergy

Figure 9.5 A

H2 + 1/2 O2

Page 7: Chapter 9 Cellular Respiration. I.Catabolic Pathways Yield Energy A.Cellular Respiration 1.C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O 2.Exergonic 3.ATP production

3. NAD+: (Nicotinamide adenine dinucleotide)a) Allows e- energy to be harvested slowly.

i. NAD+ strips 2 e-s from glucose

ii. Along with them come 2 hydrogens (NADH + H+)

iii. Very little energy is lost from the electrons here.

iv. The 2e- s can be passed to other molecules to release E. to make ATP

2H+

OH2O

ATP

ATP

ATP

Page 8: Chapter 9 Cellular Respiration. I.Catabolic Pathways Yield Energy A.Cellular Respiration 1.C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O 2.Exergonic 3.ATP production

E. The Stages of Cellular Respiration 1. Glycolysis

» Glucose (6C)Pyruvate(3C) » in Cytoplasm

2. Citric Acid Cycle» products of glycolysis broken down to CO2

» inside mitochondria

3. Electron Transport: (Oxidative Phosphorylation)

» High Energy Electrons from 1 and 2 passed down a chain of molecules to produce H2O.

» The energy released in the chain is used to make ATP via (oxidative phosphorylation)

Page 9: Chapter 9 Cellular Respiration. I.Catabolic Pathways Yield Energy A.Cellular Respiration 1.C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O 2.Exergonic 3.ATP production

F. Substrate-Level Phosphorylation: Adding a phosphate to ADP to make ATP1. phosphate from an organic molecule rather than

free floating.

Figure 9.7

Enzyme Enzyme

ATP

ADP

Product

SubstrateP

+

Page 10: Chapter 9 Cellular Respiration. I.Catabolic Pathways Yield Energy A.Cellular Respiration 1.C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O 2.Exergonic 3.ATP production

CH2O P

Glucose-6-phosphate

Glyceraldehyde-3-phosphate

II. GlycolysisC

Glucose

Hexokinase1

PA P P

PA P P

O

CH2O PC

Fructose-6-phosphate

Phosphoglucoisomerase 2

PO

CH2P CH2O O

Fructose-1,6-bisphosphate

Phosphofructokinase3

CP O

C=O

C PCH2 O

C=O

C

Aldolase4

Isomerase5

Glyceraldehyde-3-phosphate

PCH2 O

C=O

C

Dihydroxyacetone Phosphate

Page 11: Chapter 9 Cellular Respiration. I.Catabolic Pathways Yield Energy A.Cellular Respiration 1.C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O 2.Exergonic 3.ATP production

PCH2 O

C=O

C

Glyceraldehyde-3-phosphate

PCH2 O

C=O

C

P O

1,3-Bisphosphoglycerate

Triose phosphate dehydrogenase

6

PCH2 O

C=O

C

3-Phosphoglycerate

P

C

O

C=O

C

Phosphoenolpyruvate

C

C=O

C=O

Pyruvate

P

A P P

P

Phosphoglycerokinase7

P

A P P

P

C

O

C=O

C

2-Phosphoglycerate

Phosphoglyceromutase8

Enolase9

Pyruvate Kinase10

Page 12: Chapter 9 Cellular Respiration. I.Catabolic Pathways Yield Energy A.Cellular Respiration 1.C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O 2.Exergonic 3.ATP production

III. Citric Acid CycleA. Preparation

1. Pyruvate enters mitochondria

2. If oxygen is present cell resp. proceeds.

3. Acetyl CoA produced1. CO2 removed

2. Oxidation by NAD+

3. Coenzyme A attached to remaining two carbons.

4. Acetyl CoA enters the Citric Acid Cycle

Coenzyme AC

C=O

C=O

Pyruvate

O-

C

C=O

CoANAD+ NADH + H+

CO2

Page 13: Chapter 9 Cellular Respiration. I.Catabolic Pathways Yield Energy A.Cellular Respiration 1.C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O 2.Exergonic 3.ATP production

ATP

2 CO2

3 NAD+

3 NADH

+ 3 H+

ADP + P i

FAD

FADH2

Citricacidcycle

CoA

CoA

Acetyle CoA

NADH

+ 3 H+

CoA

CO2

Pyruvate(from glycolysis,2 molecules per glucose)

ATP ATP ATP

Glycolysis Citricacidcycle

Oxidativephosphorylation

Figure 9.11

Page 14: Chapter 9 Cellular Respiration. I.Catabolic Pathways Yield Energy A.Cellular Respiration 1.C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O 2.Exergonic 3.ATP production

C

C=O

CoA

Acetyl CoA

COO-

O=C

C

COO-

Oxaloacetate

COO-

HO-C

C

COO-

C

COO-

Citrate

COO-

C COO-

C

COO-

HO-C

Isocitrate

COO-

C

C

COO-

O=C

α-Ketogluterate

C

C

COO-

O=C

CoASuccinyl CoAC

C

COO-

COO-

Succinate

C

C

COO-

COO-

Fumarate

C

HO-C

COO-

COO-

Malate

COO-

O=C

C

COO-

Oxaloacetate

H2O

H2O

CO2

NAD+

NADH + H+

CO2

NAD+NADH+ H+

CoA

CoA

AP P

P

PAP P

FAD

FADH2H2O

NAD+

NADH+ H+

Page 15: Chapter 9 Cellular Respiration. I.Catabolic Pathways Yield Energy A.Cellular Respiration 1.C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O 2.Exergonic 3.ATP production

Acetyl CoA

NADH

Oxaloacetate

CitrateMalate

Fumarate

Succinate

SuccinylCoA

-Ketoglutarate

Isocitrate

Citricacidcycle

S CoA

CoA SH

NADH

NADH

FADH2

FAD

GTP GDP

NAD+

ADP

P i

NAD+

CO2

CO2

CoA SH

CoA SH

CoAS

H2O

+ H+

+ H+ H2O

C

CH3

O

O C COO–

CH2

COO–

COO–

CH2

HO C COO–

CH2

COO–

COO–

COO–

CH2

HC COO–

HO CH

COO–

CH

CH2

COO–

HO

COO–

CH

HC

COO–

COO–

CH2

CH2

COO–

COO–

CH2

CH2

C O

COO–

CH2

CH2

C O

COO–

1

2

3

4

5

6

7

8NAD+

+ H+

ATP

Figure 9.12

Results of CAC (one turn)

ATP = NADH = FADH2 =CO2 =

131

2

Page 16: Chapter 9 Cellular Respiration. I.Catabolic Pathways Yield Energy A.Cellular Respiration 1.C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O 2.Exergonic 3.ATP production

C

C=O

CoA

Acetyl CoA

COO-

O=C

C

COO-

Oxaloacetate

COO-

HO-C

C

COO-

C

COO-

Citrate

COO-

C COO-

C

COO-

HO-C

Isocitrate

COO-

C

C

COO-

O=C

α-Ketogluterate

C

C

COO-

O=C

CoASuccinyl CoAC

C

COO-

COO-

Succinate

C

C

COO-

COO-

Fumarate

C

HO-C

COO-

COO-

Malate

CoA

CoA

CoA

H2O

H2O

CO2

CO2 NAD+

NAD+

NAD+

NADH+ H+

NADH+ H+

NADH+ H+

FADFADH2 PAP P

P

AP P

Page 17: Chapter 9 Cellular Respiration. I.Catabolic Pathways Yield Energy A.Cellular Respiration 1.C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O 2.Exergonic 3.ATP production

IV. Electron Transport, Oxidative Phosphorylation and Chemiosmosis

A. Structure of Mitochondria Matrix: Juice. Site

of Citric acid cycle.

A. Cristae: Folds in the inner memebrane. Site of electron

transport.

B. Intermembrane space:

Page 18: Chapter 9 Cellular Respiration. I.Catabolic Pathways Yield Energy A.Cellular Respiration 1.C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O 2.Exergonic 3.ATP production

B. Electron Transport Overview: The following animation and diagram are an overview of the process. Definitions will follow.

-Oxidative Phosphorilation: ATP production using energy derived from redox reactions.

Page 19: Chapter 9 Cellular Respiration. I.Catabolic Pathways Yield Energy A.Cellular Respiration 1.C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O 2.Exergonic 3.ATP production

NADH

Outer Membrane

H+

Inner Membrane

Intermembrane Space

Matrix

H+

H+

FADH2FAD

OH2O

Complex 1

Complex 2

Complex

3

Complex 4

NAD+

ADP

PATP

ATP Synthase

Page 20: Chapter 9 Cellular Respiration. I.Catabolic Pathways Yield Energy A.Cellular Respiration 1.C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O 2.Exergonic 3.ATP production

ubiquinone

NADH

Outer Membrane

H+

Inner Membrane

Intermembrane Space

MatrixH+

H+

O

H2O

Complex 1

Complex 2

Complex 3

Complex 4

NAD+

ADP + P

ATP

2e -

2e-

2e-

2e- 2e -

H+

H+

H+

H+H+

H+

H+

H+ H+

ATP Synthase

Page 21: Chapter 9 Cellular Respiration. I.Catabolic Pathways Yield Energy A.Cellular Respiration 1.C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O 2.Exergonic 3.ATP production

ubiquinone

FAD

Outer Membrane

H+

Inner Membrane

Intermembrane Space

Matrix

H+

O

H2O

Complex 1

Complex 2

Complex 3

Complex 4

FADH2

ADP + P

ATP

2e-

2e-

2e- 2e -

H+

H+

H+H+

H+

H+

H+ H+

ATP Synthase2e

-

Page 22: Chapter 9 Cellular Respiration. I.Catabolic Pathways Yield Energy A.Cellular Respiration 1.C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O 2.Exergonic 3.ATP production

C. Chemiosmosis:1. The process of electron transport makes no

ATP directly.

2. Electron transport creates a H+ gradient.a. Results in high H+ amounts in the intermembrane

space.

b. This is like water build up behind a dam. It has a lot of potential energy.

c. Proton-motive force: The name given to the gradient. i. The force tries to push the protons back across the

membrane to reach equilibrium.

d. Chemiosmosis: Using energy stored in the H+ gradient across a membrane to synthesize ATP.

Page 23: Chapter 9 Cellular Respiration. I.Catabolic Pathways Yield Energy A.Cellular Respiration 1.C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O 2.Exergonic 3.ATP production

D. ATP Synthase: The enzyme that makes the ATP

1. ATP synthase is the only place protons can go back through the membrane

INTERMEMBRANE SPACE

H+

H+

H+

H+

H+

H+ H+

H+

P i

+ADP

ATP

A rotor within the membrane spins clockwise whenH+ flows past it down the H+

gradient.

A stator anchoredin the membraneholds the knobstationary.

A rod (for “stalk”)extending into the knob alsospins, activatingcatalytic sites inthe knob.

Three catalytic sites in the stationary knobjoin inorganic Phosphate to ADPto make ATP.

MITOCHONDRIAL MATRIXFigure 9.14

Page 24: Chapter 9 Cellular Respiration. I.Catabolic Pathways Yield Energy A.Cellular Respiration 1.C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O 2.Exergonic 3.ATP production

E. Energy Totals for Cellular Respiration1. ATP Formed

– Glycolysis = 2

– Pyruvate Oxydation = 0

– CAC = 2

2. NADH Generated

– Glycolysis = 2

– Pyruvate OXydation = 2

– CAC = 6

– ATP/ NADH = 3

– Total ATP from all NADH = 30

3. FADH2 Generated

– Glycolysis = 0

– Pyruvate Oxydation = 0

– CAC= 2

– ATP generated per FADH2 = 2

– Total ATP from FADH2 = 4

• Total ATP from catabolism of one glucose = 38 sometimes 36

Page 25: Chapter 9 Cellular Respiration. I.Catabolic Pathways Yield Energy A.Cellular Respiration 1.C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O 2.Exergonic 3.ATP production

V. Fermentation: Production of ATP from glucose when no oxygen is present (Anaerobic)

A. General Rules:1. Cellular respiration can’t happen w/o oxygen

2. Fermentation allows us to make ATP anyway.

3. Glycolysis makes 2 ATP by subtrate level phosphorilation. a. If done rapidly this could be enough to get by

b. The limiting factor is the amount of available NAD+ available.

4. Fermentation allows glycolysis to continue by oxidizing the NADH for reuse.

Page 26: Chapter 9 Cellular Respiration. I.Catabolic Pathways Yield Energy A.Cellular Respiration 1.C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O 2.Exergonic 3.ATP production

B. Types: 1. Alcohol Fermentation: Pyruvate is converted to

ethanol.– Often used by bacteria and yeast

– Step 1: Pyruvate releases 2CO2 Acetaldehyde

– Step 2: Acetaldehyde oxidizes NADH ethanol and NAD+

2 ADP + 2 P1 2 ATP

GlycolysisGlucose

2 NAD+ 2 NADH

2 Pyruvate

2 Acetaldehyde 2 Ethanol

(a) Alcohol fermentation

H

H OH

CH3

C

O –

OC

C O

CH3

H

C O

CH3

CO22

Page 27: Chapter 9 Cellular Respiration. I.Catabolic Pathways Yield Energy A.Cellular Respiration 1.C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O 2.Exergonic 3.ATP production

2 ADP + 2 P1 2 ATP

GlycolysisGlucose

2 NAD+ 2 NADH

2 Pyruvate

2 Acetaldehyde 2 Ethanol

(a) Alcohol fermentation

2 ADP + 2 P1 2 ATP

GlycolysisGlucose

2 NAD+ 2 NADH

2 Lactate

(b) Lactic acid fermentation

H

H OH

CH3

C

O –

OC

C O

CH3

H

C O

CH3

O–

C O

C O

CH3O

C O

C OHH

CH3

CO22

Figure 9.17

2. Lactic Acid Fermentation1. Happens in human muscles as well as bacteria that

make cheese.

2. One Step: Pyruvate oxidizes NADH NAD+ + Lactic Acid.

Page 28: Chapter 9 Cellular Respiration. I.Catabolic Pathways Yield Energy A.Cellular Respiration 1.C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O 2.Exergonic 3.ATP production

c. Comparing Fermentation and Cellular Respiration

Cellular Respiration1.Aerobic2.38 ATP produced3.NADH oxidized to produce H20

Fermentation1.Anaerobic2.2 ATP produced3.NADH oxidized to make ethanol or lactate