Download pdf - Cellular Respiration - Henry County Public Schools€¦ · Cellular Respiration A catabolic, exergonic, oxygen (O 2) requiring process that uses energy extracted from macromolecules

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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).

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.

Inner

membrane

Outer

membrane

Inner

membrane space Matrix

Cristae

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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.

Or the gain of oxygen.


glucose ATP

Oxidation

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Reduction Reaction

The gain of electrons to a substance.

Or the loss of oxygen.

glucose ATP


Reduction

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Breakdown of Cellular Respiration

Four main parts (reactions).

1. Glycolysis (splitting of sugar)

a. cytosol, just outside of mitochondria.

2. Grooming Phase

a. migration from cytosol to matrix.

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Breakdown of Cellular Respiration

3. Krebs Cycle (Citric Acid Cycle)

a. mitochondrial matrix

4. Electron Transport Chain (ETC) and

Oxidative Phosphorylation

a. Also called Chemiosmosis

b. inner mitochondrial membrane.

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1. Glycolysis

Occurs in the cytosol just outside of mitochondria.

Two phases (10 steps): A. Energy investment phase

a. Preparatory phase (first 5 steps). B. Energy yielding phase

a. Energy payoff phase (second 5 steps).

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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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1. Glycolysis

Total Net Yield

2 - 3C-Pyruvate (PYR)

2 - ATP (Substrate-level Phosphorylation)

2 - NADH

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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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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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2. Grooming Phase

End Products: grooming phase

2 - NADH

2 - CO2

2- Acetyl CoA (2C)

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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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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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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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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) and Oxidative Phosphorylation

(Chemiosmosis)

Location: inner mitochondrial membrane.

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

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

Inner

Mitochondrial

Membrane

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(Chemiosmosis)

The H+ then move via diffusion (Proton Motive Force) 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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(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

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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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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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