Energy and Metabolism

I. Energy Basics

I. Energy Basics

A. Forms of Energy

- energy is the capacity to cause change

I. Energy Basics

A. Forms of Energy

- energy is the capacity to cause change

1. kinetic = energy of a moving body - thermal = energy of moving atoms

- light = energy of moving photons- electricity = energy of moving charge

2. potential = energy in matter due to location/structure - potential kinetic (position) - potential electric (like in a battery or across a membrane) - chemical (energy that can be release by the breaking of chemical

bonds)

I. Energy Basics

A. Forms of EnergyB. Laws of Thermodynamics

I. Energy Basics

A. Forms of EnergyB. Laws of Thermodynamics

1. Conservation of Energy:Energy/matter can not be

created or destroyed, but it can be transferred and transformed.

I. Energy Basics

A. Forms of EnergyB. Laws of Thermodynamics

1. Conservation of Energy:Energy/matter can not be

created or destroyed, but it can be transferred and transformed.

2. Law of Entropy:Every energy

transformation increases the entropy of the universe.

4H 2 He + E = light ELight E Thermal E of skin, waterThermal E of skin Thermal E of waterPotential on board Kinetic of diverChemical E thermal body heatChemical E kinetic E of musclesKinetic E of muscles Potential E on board

Transformations

TransformationsInefficiencies

Open systems can increase in local complexity as long as “energy in” exceeds the energy needed to increase the complexity of the system; such that there is still an increase in “energy out” - the entropy of the universe … so that the total energy of the universe remains constant and entropy increases.

P E W

En

TransformationsInefficiencies

Open systems can increase in local complexity as long as “energy in” exceeds the energy needed to increase the complexity of the system; such that there is still an increase in “energy out” - the entropy of the universe … so that the total energy of the universe remains constant and entropy increases.

P E

Life En

TransformationsInefficiencies

Open systems can increase in local complexity as long as “energy in” exceeds the energy needed to increase the complexity of the system; such that there is still an increase in “energy out” - the entropy of the universe … so that the total energy of the universe remains constant and entropy increases.

P E

Life En

II. Metabolism Overview

A. Catabolism and Anabolism:

TO build a useful biomolecule (anabolism) or to do mechanical work (kinetic energy), the matter and energy must come from somewhere…. Except for photosynthesis, the source of energy used in living systems is chemical potential energy, harvested by catabolic processes called CELLULAR RESPIRATION.

CATABOLISM

“ENTROPY”ENERGY FOR:

ANABOLISM WORK

Chemical Potential Energy

Energy+

Energy+

Energy+

Energy+

ATP ADP + P + Energy

Coupled Reaction

Coupled Reaction

II. Metabolism Overview

A. Catabolism and Anabolism:

B. Cell Respiration: Harvesting Energyfrom Molecules

MATTER and ENERGY in FOOD

MONOMERS and WASTE

DIGESTION AND CELLULAR RESPIRATION

ADP + P ATP

B. Cell Respiration:

Focus on core process…Glucose metabolism

B. Cell Respiration:

Focus on core process…Glucose metabolism

GLYCOLYSIS

B. Cell Respiration:

Focus on core process…Glucose metabolism

GLYCOLYSIS

Oxygen Present? Oxygen Absent?Aerobic Resp. Anaerobic Resp.

B. Cell Respiration:

Focus on core process…Glucose metabolism

GLYCOLYSIS

Oxygen Present? Oxygen Absent?

Fermentation

A little ATP

B. Cell Respiration:

Focus on core process…Glucose metabolism

GLYCOLYSIS

Oxygen Present? Oxygen Absent?

Fermentation

A little ATP

GatewayCACETC

LOTS OF ATP

B. Respiration:

1. Glycolysis: - Occurs in presence OR absence of oxygen gas. - All cells do this! (very primitive pathway) - Occurs in the cytoplasm of all cells

LE 9-8

Energy investment phase

Glucose

2 ATP used2 ADP + 2 P

4 ADP + 4 P 4 ATP formed

2 NAD+ + 4 e– + 4 H+

Energy payoff phase

+ 2 H+2 NADH

2 Pyruvate + 2 H2O

2 Pyruvate + 2 H2O

2 ATP

2 NADH + 2 H+

Glucose

4 ATP formed – 2 ATP used

2 NAD+ + 4 e– + 4 H+

Net

Glycolysis

ATPATPATP

LE 9-8

Energy investment phase

Glucose

2 ATP used2 ADP + 2 P

4 ADP + 4 P 4 ATP formed

2 NAD+ + 4 e– + 4 H+

Energy payoff phase

+ 2 H+2 NADH

2 Pyruvate + 2 H2O

2 Pyruvate + 2 H2O

2 ATP

2 NADH + 2 H+

Glucose

4 ATP formed – 2 ATP used

2 NAD+ + 4 e– + 4 H+

Net

Glycolysis

ATPATPATP

What's needed to keep the reaction going?

LE 9-8

Energy investment phase

Glucose

2 ATP used2 ADP + 2 P

4 ADP + 4 P 4 ATP formed

2 NAD+ + 4 e– + 4 H+

Energy payoff phase

+ 2 H+2 NADH

2 Pyruvate + 2 H2O

2 Pyruvate + 2 H2O

2 ATP

2 NADH + 2 H+

Glucose

4 ATP formed – 2 ATP used

2 NAD+ + 4 e– + 4 H+

Net

Glycolysis

ATPATPATP

What's needed t keep the reaction going?

- glucose.... (moot)

LE 9-8

Energy investment phase

Glucose

2 ATP used2 ADP + 2 P

4 ADP + 4 P 4 ATP formed

2 NAD+ + 4 e– + 4 H+

Energy payoff phase

+ 2 H+2 NADH

2 Pyruvate + 2 H2O

2 Pyruvate + 2 H2O

2 ATP

2 NADH + 2 H+

Glucose

4 ATP formed – 2 ATP used

2 NAD+ + 4 e– + 4 H+

Net

Glycolysis

ATPATPATP

What's needed to keep the reaction going?

- glucose....

- ATP... but previous rxn made some, so that's there

LE 9-8

Energy investment phase

Glucose

2 ATP used2 ADP + 2 P

4 ADP + 4 P 4 ATP formed

2 NAD+ + 4 e– + 4 H+

Energy payoff phase

+ 2 H+2 NADH

2 Pyruvate + 2 H2O

2 Pyruvate + 2 H2O

2 ATP

2 NADH + 2 H+

Glucose

4 ATP formed – 2 ATP used

2 NAD+ + 4 e– + 4 H+

Net

Glycolysis

ATPATPATP

What's needed to keep the reaction going?

- glucose....

- ATP... but previous rxn made some, so that's there

- and you need NAD to accept the electrons....

LE 9-8

Energy investment phase

Glucose

2 ATP used2 ADP + 2 P

4 ADP + 4 P 4 ATP formed

2 NAD+ + 4 e– + 4 H+

Energy payoff phase

+ 2 H+2 NADH

2 Pyruvate + 2 H2O

2 Pyruvate + 2 H2O

2 ATP

2 NADH + 2 H+

Glucose

4 ATP formed – 2 ATP used

2 NAD+ + 4 e– + 4 H+

Net

Glycolysis

ATPATPATP

What's needed to keep the reaction going?

- glucose....

- ATP... but previous rxn made some, so that's there

- and you need NAD to accept the electrons....

AS GLYCOLYSIS PROCEEDS, THE [NAD+] DECLINES AND CAN BECOME LIMITING....

LE 9-8

Energy investment phase

Glucose

2 ATP used2 ADP + 2 P

4 ADP + 4 P 4 ATP formed

2 NAD+ + 4 e– + 4 H+

Energy payoff phase

+ 2 H+2 NADH

2 Pyruvate + 2 H2O

2 Pyruvate + 2 H2O

2 ATP

2 NADH + 2 H+

Glucose

4 ATP formed – 2 ATP used

2 NAD+ + 4 e– + 4 H+

Net

Glycolysis

ATPATPATP

What's needed to keep the reaction going?

- glucose....

- ATP... but previous rxn made some, so that's there

- and you need NAD to accept the electrons....

AS GLYCOLYSIS PROCEEDS, THE [NAD+] DECLINES AND CAN BECOME LIMITING....

CELLS HAVE EVOLVED TO RECYCLE NAD+..... SO GLYCOLYSIS CAN CONTINUE....

LE 9-18

Pyruvate

Glucose

CYTOSOL

No O2 presentFermentation

Ethanolor

lactate

Acetyl CoA

MITOCHONDRION

O2 present Cellular respiration

Citricacidcycle

NAD+ NAD+PYRUVATE

B. Respiration

1. Glycolysis:2. Anaerobic Respiration a. in plants, fungi, and bacteria: Ethyl Alcohol Fermentation

LE 9-17a

CO2+ 2 H+

2 NADH2 NAD+

2 Acetaldehyde

2 ATP2 ADP + 2 P i

2 Pyruvate

2

2 Ethanol

Alcohol fermentation

Glucose Glycolysis

B. Respiration:

1. Glycolysis:2. Anaerobic Respiration

- Glycolosis a. in plants, fungi, and bacteria: Ethyl Alcohol Fermentation b. in animals: Lactic Acid Fermentation

LE 9-17b

+ 2 H+

2 NADH2 NAD+

2 ATP2 ADP + 2 P i

2 Pyruvate

2 Lactate

Lactic acid fermentation

Glucose Glycolysis

B. Respiration:

1. Glycolysis:2. Anaerobic Respiration

- Glycolosis a. in plants, fungi, and bacteria: Ethyl Alcohol Fermentation b. in animals: Lactic Acid Fermentation

In both processes, NAD is recycled so glycolysis can continue… that is the primary goal

Energy harvest by glycolysis can continue at a low rate.

B. Respiration:1. Glycolysis:2. Anaerobic Respiration3. Aerobic Respiration

B. Respiration:

1. Glycolysis:2. Anaerobic Respiration3. Aerobic Respiration (in mitochondria of eukaryotic cells)

- Had Glycolysis: C6 (glucose) 2C3 (pyruvate) + ATP, NADH

a - Gateway step: 2C3 2C2 (acetyl) + 2C (CO2) + NADH

b - Citric Acid Cycle: 2C2 (acetyl) 4C (CO2) + NADH, FADH, ATP

c - Electron Transport Chain: convert energy in NADH, FADH to ATP

LE 9-10

Pyruvate

NAD+

Transport protein

NADH + H+

Coenzyme ACO2

Acetyl Co A

energy harvested as NADH

Gateway step: 2C3 2C2 (acetyl) + 2C (CO2) + NADH

B. Respiration:

1. Glycolysis:2. Anaerobic Respiration3. Aerobic Respiration (in mitochondria of eukaryotic cells)

- Had Glycolysis: C6 (glucose) 2C3 (pyruvate) + ATP, NADH

a - Gateway step: 2C3 2C2 (acetyl) + 2C (CO2) + NADH

b - Citric Acid Cycle: 2C2 (acetyl) 4C (CO2) + NADH, FADH, ATP

c - Electron Transport Chain: convert energy in NADH, FADH to ATP

b - Citric Acid Cycle: 2C2 (acetyl) 4C (CO2) + NADH, FADH, ATP

b - Citric Acid Cycle: 2C2 (acetyl) 4C (CO2) + NADH, FADH, ATP

1. C2 (acetyl) binds to C4 (oxaloacetate), making a C6 molecule (citrate)

b - Citric Acid Cycle: 2C2 (acetyl) 4C (CO2) + NADH, FADH, ATP

1. C2 (acetyl) binds to C4 (oxaloacetate), making a C6 molecule (citrate)

2. One C is broken off (CO2) and NAD accepts energy (NADH)

b - Citric Acid Cycle: 2C2 (acetyl) 4C (CO2) + NADH, FADH, ATP

1. C2 (acetyl) binds to C4 (oxaloacetate), making a C6 molecule (citrate)

2. One C is broken off (CO2) and NAD accepts energy (NADH)

3. The second C is broken off (CO2) and NAD accepts the energy…at this point the acetyl group has been split!!

b - Citric Acid Cycle: 2C2 (acetyl) 4C (CO2) + NADH, FADH, ATP

1. C2 (acetyl) binds to C4 (oxaloacetate), making a C6 molecule (citrate)

2. One C is broken off (CO2) and NAD accepts energy (NADH)

3. The second C is broken off (CO2) and NAD accepts the energy…at this point the acetyl group has been split!!

4. The C4 molecules is rearranged, regenerating the oxaloacetate; releasing energy that is stored in ATP, FADH, and NADH.

b - Citric Acid Cycle: 2C2 (acetyl) 4C (CO2) + NADH, FADH, ATP

1. C2 (acetyl) binds to C4 (oxaloacetate), making a C6 molecule (citrate)

2. One C is broken off (CO2) and NAD accepts energy (NADH)

3. The second C is broken off (CO2) and NAD accepts the energy…at this point the acetyl group has been split!!

4. The C4 molecules is rearranged, regenerating the oxaloacetate; releasing energy that is stored in ATP, FADH, and NADH.

5. In summary, the C2 acetyl is split and the energy released is trapped in ATP, FADH, and 3 NADH. (this occurs for EACH of the 2 pyruvates from the initial glucose).

B. Respiration:

1. Glycolysis:2. Anaerobic Respiration3. Aerobic Respiration a - Glycolysis: C6 (glucose) 2C3 (pyruvate) + ATP, NADH

b - Gateway step: 2C3 2C2 (acetyl) + 2C (CO2) + NADH

c - Citric Acid Cycle: 2C2 (acetyl) 4C (CO2) + NADH, FADH, ATP

d - Electron Transport Chain: convert energy in NADH, FADH to ATP

d - Electron Transport Chain: transfer energy in NADH, FADH to ATP

LE 9-13

ATP ATP ATP

GlycolysisOxidative

phosphorylation:electron transportand chemiosmosis

Citricacidcycle

NADH

50

FADH2

40 FMNFe•S

I FADFe•S II

IIIQ

Fe•SCyt b

30

20

Cyt cCyt c1

Cyt aCyt a3

IV

10

0

Multiproteincomplexes

Free

ene

rgy

(G) r

elat

ive

to O

2 (k

cal/m

ol)

H2O

O22 H+ + 1/2

electron

ADP + P

ATP

RELEASES ENERGY

STORES ENERGY

LE 9-13

ATP ATP ATP

GlycolysisOxidative

phosphorylation:electron transportand chemiosmosis

Citricacidcycle

NADH

50

FADH2

40 FMNFe•S

I FADFe•S II

IIIQ

Fe•SCyt b

30

20

Cyt cCyt c1

Cyt aCyt a3

IV

10

0

Multiproteincomplexes

Free

ene

rgy

(G) r

elat

ive

to O

2 (k

cal/m

ol)

H2O

O22 H+ + 1/2

electron

ADP + P

ATP

RELEASES ENERGY

STORES ENERGY

HEY!!! Here’s the first time O2 shows up!!! It is the final electron acceptor, and water is produced as a waste product!

LE 9-15

Protein complexof electroncarriers

H+

ATP ATP ATP

GlycolysisOxidative

phosphorylation:electron transportand chemiosmosis

Citricacidcycle

H+

Q

IIII

II

FADFADH2

+ H+NADH NAD+

(carrying electronsfrom food)

Innermitochondrialmembrane

Innermitochondrialmembrane

Mitochondrialmatrix

Intermembranespace

H+

H+

Cyt c

IV

2H+ + 1/2 O2 H2O

ADP +

H+

ATP

ATPsynthase

Electron transport chainElectron transport and pumping of protons (H+),

Which create an H+ gradient across the membrane

P i

ChemiosmosisATP synthesis powered by the flow

of H+ back across the membrane

Oxidative phosphorylation

ETC: energy and electrons from NADH and FADH are used to pump H+ against gradient to inner membrane space…potential E.

LE 9-15

Protein complexof electroncarriers

H+

ATP ATP ATP

GlycolysisOxidative

phosphorylation:electron transportand chemiosmosis

Citricacidcycle

H+

Q

IIII

II

FADFADH2

+ H+NADH NAD+

(carrying electronsfrom food)

Innermitochondrialmembrane

Innermitochondrialmembrane

Mitochondrialmatrix

Intermembranespace

H+

H+

Cyt c

IV

2H+ + 1/2 O2 H2O

ADP +

H+

ATP

ATPsynthase

Electron transport chainElectron transport and pumping of protons (H+),

Which create an H+ gradient across the membrane

P i

ChemiosmosisATP synthesis powered by the flow

of H+ back across the membrane

Oxidative phosphorylation

ETC: energy and electrons from NADH and FADH are used to pump H+ against gradient to inner membrane space…potential E.

Chemiosmosis: E in flow of H+ used to make bond in ATP.

B. Respiration:

1. Glycolysis:2. Anaerobic Respiration3. Aerobic Respiration a - Glycolysis: C6 (glucose) 2C3 (pyruvate) + ATP, NADH

b - Gateway step: 2C3 2C2 (acetyl) + 2C (CO2) + NADH

c - Citric Acid Cycle: 2C2 (acetyl) 4C (CO2) + NADH, FADH, ATP

d - Electron Transport Chain: convert energy in NADH, FADH to ATP

- OXYGEN is just an electron ACCEPTOR - WATER is produced as a metabolic waste - All carbons in glucose have been separated - Energy has been harvested and stored in bonds in ATP

If O2 is NOT present, the ETC backs up and NADH and FADH can’t give up their electrons and H+ to the ETC

If O2 is NOT present, the ETC backs up and NADH and FADH can’t give up their electrons and H+ to the ETC

What happens then????

If O2 is NOT present, the ETC backs up and NADH and FADH can’t give up their electrons and H+ to the ETC

NADH is recycled through FERMENTATION to NAD so at least GLYCOLYSIS can continue!!

FOOD CO2, water, and waste

ADP + PATP

ANABOLISM WORK

Phosphorylation of myosin causes it to toggle and bond to actin; release of phosphate causes it to return to low energy state and pull actin…contraction.

FOOD CO2, water, and waste

ADP + PATP

ANABOLISM WORK