requiring energy cellular respiration - mrs. kohout's...

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12/6/2012 1 1 Cellular Respiration 2 Cellular Respiration A catabolic, exergonic, oxygen (O 2 ) requiring process that uses energy extracted from macromolecules (glucose) to produce energy (ATP) and water (H 2 O). Equation for CR? C 6 H 12 O 6 + 6O 2 6CO2 + 6H 2 O + energy glucose ATP 3 Question: In what kinds organisms does cellular respiration take place? 4 Plants and Animals Plants Autotrophs: self-producers. Animals Heterotrophs: consumers. 5 Mitochondria Organelle where cellular respiration takes place. 6 Redox Reaction = Transfer of one or more electrons from one reactant to another. Two types: 1. Oxidation 2. Reduction

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Page 1: requiring energy Cellular Respiration - Mrs. Kohout's ...kohoutbio.weebly.com/uploads/1/3/3/4/13345736/cellular_respiration_ppt.pdf · Cellular Respiration 2 Cellular Respiration

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Cellular Respiration

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Cellular Respiration

A catabolic, exergonic, oxygen (O2) requiring process that uses energy extracted from macromolecules (glucose) to produce energy (ATP) and water (H2O).

Equation for CR?

C6H12O6 + 6O2 6CO2 + 6H2O + energy

glucose ATP

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Question:

In what kinds organisms does cellular respiration take place?

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Plants and Animals

Plants

Autotrophs: self-producers.

Animals

Heterotrophs: consumers.

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Mitochondria Organelle where cellular respiration takes

place.

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Redox Reaction

= Transfer of one or more electrons from one reactant to another.

Two types:

1. Oxidation

2. Reduction

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Oxidation Reaction

= The loss of electrons from a substance. (think backwards)

Or the gain of oxygen.

C6H12O6 + 6O2 6CO2 + 6H2O + energy

glucose ATP

Oxidation

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Reduction Reaction

The gain of electrons to a substance.

Or the loss of oxygen.

glucose ATP

C6H12O6 + 6O2 6CO2 + 6H2O + energy

Reduction

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Breakdown of Cellular Respiration

Four main parts (reactions).

1. Glycolysis (splitting of sugar) Glyco = sugar

Lysis = split

cytoplasm, just outside of mitochondria.

Glucose 2 molecules pyruvic acid

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Just so we’re on the same page…

What is NADH?

NAD is an electron carrier much like NADP+ (photosynthesis) Glycolysis gives off 4 electrons.

2NAD’s pick up the 4 e- (2 each) and become NADH.

NADH holds the electrons until they can be transferred to other molecules

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Breakdown of Cellular Respiration

2. Grooming Phase migration from cytosol to matrix.

3. Krebs Cycle (Citric Acid Cycle)

mitochondrial matrix

4. Electron Transport Chain (ETC) and Oxidative Phosphorylation a. Also called Chemiosmosis b. inner mitochondrial membrane.

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The breakdown

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1. Glycolysis

Occurs in the cytosol just outside of mitochondria.

Two phases

A. Energy investment phase

a. Preparatory phase (first steps). B. Energy yielding phase

a. Energy payoff phase (second steps).

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Glycolysis is an energy releasing reaction. Is energy necessary for glycolysis to start? Why? Need ATP to get things going.

Analogy –earn interest, must put in $ first

4 ATP are released in glycolysis for a net gain of 2 ATP – (“interest” is earned right away)

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1. Glycolysis

Total Net Yield

2 - 3C-Pyruvate (PYR)

2 - ATP (Substrate-level Phosphorylation)

2 - NADH

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3. Krebs Cycle (Citric Acid Cycle)

Location: mitochondrial matrix.

Acetyl CoA (2C) bonds to Oxalacetic acid (4C - OAA) to make Citrate (6C).

It takes 2 turns of the krebs cycle to oxidize 1 glucose molecule.

Mitochondrial

Matrix

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3. Krebs Cycle (Citric Acid Cycle)

Total net yield (2 turns of krebs cycle)

1. 2 - ATP (substrate-level phosphorylation)

2. 6 - NADH

3. 2 - FADH2

4. 4 - CO2

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4. Electron Transport Chain (ETC)

Location: inner mitochondrial membrane.

Uses ETC (proteins) and ATP Synthase (enzyme) to make ATP.

ETC pumps H+ (protons) across inner membrane (lowers pH in inner membrane space).

Inner

Mitochondrial

Membrane

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4. Electron Transport Chain (ETC)

The H+ then move via diffusion through ATP Synthase to make ATP.

All NADH and FADH2 converted to ATP during this stage of cellular respiration.

Each NADH converts to 3 ATP.

Each FADH2 converts to 2 ATP (enters the ETC at a lower level than NADH).

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That’s all for now….

Until we draw the cycles!!!

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1. Glycolysis

A. Energy Investment Phase:

Glucose (6C)

Glyceraldehyde phosphate (2 - 3C)

(G3P or GAP)

2 ATP - used

0 ATP - produced

0 NADH - produced

2ATP

2ADP + P

C-C-C-C-C-C

C-C-C C-C-C

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1. Glycolysis

B. Energy Yielding Phase

Glyceraldehyde phosphate (2 - 3C)

(G3P or GAP)

Pyruvate (2 - 3C)

(PYR)

0 ATP - used

4 ATP - produced

2 NADH - produced 4ATP

4ADP + P

C-C-C C-C-C

C-C-C C-C-C

GAP GAP

(PYR) (PYR)

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Substrate-Level Phosphorylation

ATP is formed when an enzyme transfers a phosphate group from a substrate to ADP. Enzyme

Substrate

O-

C=O

C-O-

CH2

P P P Adenosine

ADP (PEP)

Example:

PEP to PYR

P P P

ATP

O-

C=O

C=O

CH2

Product

(Pyruvate)

Adenosine

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2. Grooming Phase

End Products: grooming phase

2 - NADH

2 - CO2

2- Acetyl CoA (2C)

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3. Krebs Cycle (Citric Acid Cycle)

Krebs

Cycle

1 Acetyl CoA (2C)

3 NAD+

3 NADH

FAD

FADH2

ATP ADP + P

(one turn)

OAA (4C) Citrate (6C)

2 CO2

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3. Krebs Cycle (Citric Acid Cycle)

Krebs

Cycle

2 Acetyl CoA (2C)

6 NAD+

6 NADH

2 FAD

2 FADH2

2 ATP 2 ADP + P

(two turns)

OAA (4C) Citrate (6C)

4 CO2

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4. Electron Transport Chain (ETC) and Oxidative Phosphorylation (Chemiosmosis)

Inner

membrane

Outer

membrane

Inner

membrane space Matrix

Cristae

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4. ETC and Oxidative Phosphorylation

(Chemiosmosis for NADH)

NADH

+ H+

ATP

Synthas

e

1H+ 2H+ 3H+

higher H+

concentration

H+

ADP + ATP

lower H+

concentration

H+

(Proton Pumping)

P

E T C

NAD+

2H+ + 1/2O2 H2O

Intermembrane Space

Matrix

Inner

Mitochondrial

Membrane

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4. ETC and Oxidative Phosphorylation (Chemiosmosis for FADH2)

FADH2 + H+

ATP

Synthas

e

1H+ 2H+

higher H+

concentration

H+

ADP + ATP

lower H+

concentration

H+

(Proton Pumping)

P

E T C

FAD+ 2H+ +

1/2O2

H2O

Intermembrane Space

Matrix

Inner

Mitochondrial

Membrane

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TOTAL ATP YIELD

1. 04 ATP - substrate-level phosphorylation

2. 34 ATP - ETC & oxidative phosphorylation

38 ATP - TOTAL YIELD

ATP 32

Eukaryotes (Have Membranes)

Total ATP Yield

02 ATP - glycolysis (substrate-level phosphorylation)

04 ATP - converted from 2 NADH - glycolysis

06 ATP - converted from 2 NADH - grooming phase

02 ATP - Krebs cycle (substrate-level phosphorylation)

18 ATP - converted from 6 NADH - Krebs cycle

04 ATP - converted from 2 FADH2 - Krebs cycle

36 ATP - TOTAL

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Maximum ATP Yield for Cellular Respiration (Eukaryotes)

36 ATP (maximum per glucose)

Glucose

Glycolysis

2ATP 4ATP 6ATP 18ATP 4ATP 2ATP

2 ATP (substrate-level phosphorylation)

2NADH

2NADH

6NADH

Krebs

Cycle

2FADH2

2 ATP (substrate-level phosphorylation)

2 Pyruvate

2 Acetyl CoA

ETC and Oxidative

Phosphorylation

Cytosol

Mitochondria

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Fermentation

Occurs in cytosol when “NO Oxygen” is present (called anaerobic).

Remember: glycolysis is part of fermentation.

Two Types:

1. Alcohol Fermentation

2. Lactic Acid Fermentation

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Alcohol Fermentation

Plants and Fungi beer and wine

glucose

Glycolysis

C

C

C

C

C

C

C

C

C 2 Pyruvic

acid

2ATP 2ADP

+ 2

2NADH

P

2 NAD+

C

C

2 Ethanol 2CO2

released

2NADH 2 NAD+

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Alcohol Fermentation

End Products: Alcohol fermentation

2 - ATP (substrate-level phosphorylation)

2 - CO2

2 - Ethanol’s

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Lactic Acid Fermentation

Animals (pain in muscle after a workout).

2 Lactic

acid

2NADH 2 NAD+

C

C

C

Glucose

Glycolysis C

C

C

2 Pyruvic

acid

2ATP 2ADP

+ 2

2NADH

P

2 NAD+

C

C

C

C

C

C

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Lactic Acid Fermentation

End Products: Lactic acid fermentation

2 - ATP (substrate-level phosphorylation)

2 - Lactic Acids

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2. Grooming Phase

Occurs when Oxygen is present (aerobic).

2 Pyruvate (3C) molecules are transported through the mitochondria membrane to the matrix and is converted to 2 Acetyl CoA (2C) molecules.

Cytosol C

C

C 2 Pyruvate

2 CO2

2 Acetyl CoA C-C

2NADH 2 NAD+

Matrix

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Prokaryotes (Lack Membranes)

Total ATP Yield

02 ATP - glycolysis (substrate-level phosphorylation)

06 ATP - converted from 2 NADH - glycolysis

06 ATP - converted from 2 NADH - grooming phase

02 ATP - Krebs cycle (substrate-level phosphorylation)

18 ATP - converted from 6 NADH - Krebs cycle

04 ATP - converted from 2 FADH2 - Krebs cycle

38 ATP - TOTAL

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Question:

In addition to glucose, what other various food molecules are use in Cellular Respiration?

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Catabolism of Various Food Molecules

Other organic molecules used for fuel.

1. Carbohydrates: polysaccharides

2. Fats: glycerol’s and fatty acids

3. Proteins: amino acids

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