cellular respiration - citrus...

Cellular RespirationCellular Respiration

Cellular RespirationCellular Respiration• A catabolic, exergonic, oxygen (Ocatabolic, exergonic, oxygen (O22)) requiring

process that uses energyenergy extracted from macromolecules (glucose)macromolecules (glucose) to produce energy energy (ATP)(ATP) and water (Hwater (H22O).O).

C6H12O6 + 6O2 → 6CO2 + 6H2O + energy

glucoseglucose ATP

Question:Question:

•• In what kinds organisms does cellular In what kinds organisms does cellular respiration take place?respiration take place?

Plants and AnimalsPlants and Animals

•• Plants Plants -- AutotrophsAutotrophs: self-producers.• Animals - Heterotrophs: consumers.

MitochondriaMitochondria•• OrganelleOrganelle where cellular respirationcellular respiration takes place.

Innermembrane

Outermembrane

Innermembrane space

Matrix Cristae

Redox ReactionRedox Reaction

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

•• Two types:Two types:1.1. OxidationOxidation2.2. ReductionReduction

Oxidation ReactionOxidation Reaction

• The lossloss of electrons from a substance.• Or the gaingain of oxygenoxygen.

C6H12O6 + 6O2 → 6CO2 + 6H2O + energy

glucose ATP

OxidationOxidation

Reduction ReactionReduction Reaction

• The gaingain of electrons to a substance.• Or the lossloss of oxygenoxygen.

glucose ATP

C6H12O6 + 6O2 → 6CO2 + 6H2O + energy

ReductionReduction

Breakdown of Cellular RespirationBreakdown of Cellular Respiration

•• Four main parts (reactions).Four main parts (reactions).

1. Glycolysis (splitting of sugar)1. Glycolysis (splitting of sugar)a. cytosol, just outside of mitochondria.

2. Grooming Phase2. Grooming Phasea. migration from cytosol to matrix.

Breakdown of Cellular RespirationBreakdown of Cellular Respiration

3. Krebs Cycle (Citric Acid Cycle)3. Krebs Cycle (Citric Acid Cycle)a. mitochondrial matrix

4. Electron Transport Chain (ETC) and4. Electron Transport Chain (ETC) andOxidative PhosphorylationOxidative Phosphorylation

a. Also called Chemiosmosisb. inner mitochondrial membrane.

1. Glycolysis1. Glycolysis

• Occurs in the cytosol just outside of mitochondria.

•• Two phases (10 steps):Two phases (10 steps):

A. Energy investment phaseA. Energy investment phasea. Preparatory phase (first 5 steps).

B. Energy yielding phaseB. Energy yielding phasea. Energy payoff phase (second 5 steps).


A. Energy Investment Phase:A. Energy Investment Phase:

Glucose (6C)

Glyceraldehyde phosphate (2 - 3C)(G3P or GAP)

2 ATP - used0 ATP - produced0 NADH - produced

2ATP

2ADP + P

C-C-C-C-C-C

C-C-C C-C-C


B. Energy Yielding PhaseB. Energy Yielding Phase

Glyceraldehyde phosphate (2 - 3C)(G3P or GAP)

Pyruvate (2 - 3C)(PYR)

0 ATP - used4 ATP - produced2 NADH - produced

4ATP

4ADP + P

C-C-C C-C-C

C-C-C C-C-C

GAP GAP

(PYR) (PYR)


•• Total Net YieldTotal Net Yield

2 - 3C-Pyruvate (PYR)2 - ATP (Substrate-level Phosphorylation)2 - NADH

Substrate-Level Phosphorylation• ATP is formed when an enzyme transfers a

phosphate groupphosphate group from a substrate to ADP.

Enzyme

Substrate

O-

C=OC-O-CH2

P P P Adenosine

ADP(PEP)Example:PEP to PYR

P PPATP

O-

C=OC=OCH2

Product(Pyruvate)

Adenosine

Fermentation Fermentation

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

• Remember: glycolysisglycolysis is part of fermentationfermentation.

•• Two Types:Two Types:

1.1. Alcohol FermentationAlcohol Fermentation

2. Lactic Acid Fermentation2. Lactic Acid Fermentation

Alcohol FermentationAlcohol Fermentation

•• Plants and FungiPlants and Fungi →→ beer and winebeer and wine

glucose

Glycolysis

CCCCCC

CCC

2 Pyruvicacid

2ATP2ATP2ADP+ 2

2NADH

P

2 NAD+

CC

2 Ethanol2 Ethanol2CO2CO22releasedreleased

2NADH 2 NAD+

Alcohol FermentationAlcohol Fermentation

•• End Products: Alcohol fermentationEnd Products: Alcohol fermentation

2 - ATP (substrate-level phosphorylation)

2 - CO2

2 - Ethanol’sDuffBeer

Lactic Acid FermentationLactic Acid Fermentation

•• Animals (pain in muscle after a workout).Animals (pain in muscle after a workout).

2 Lactic2 Lacticacidacid

2NADH 2 NAD+

CCC

Glucose

GlycolysisCCC

2 Pyruvicacid

2ATP2ATP2ADP+ 2

2NADH

P

2 NAD+

CCCCCC

Lactic Acid FermentationLactic Acid Fermentation

•• End Products: Lactic acid fermentationEnd Products: Lactic acid fermentation

2 - ATP (substrate-level phosphorylation)

2 - Lactic Acids

2. Grooming Phase2. Grooming Phase

• Occurs when Oxygen is present (aerobic).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.

CytosolCCC

2 Pyruvate

2 CO2 CO22

2 Acetyl CoA2 Acetyl CoACC--CC

2NADH2NADH2 NAD+

Matrix

2. Grooming Phase2. Grooming Phase

•• End Products: End Products: grooming phasegrooming phase

2 2 -- NADHNADH

2 2 -- COCO22

22-- Acetyl CoA (2C)Acetyl CoA (2C)

3. Krebs Cycle (Citric Acid Cycle)3. Krebs Cycle (Citric Acid Cycle)

•• Location: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 oxidize1 glucose molecule.

MitochondrialMatrix


KrebsCycle

1 Acetyl CoA (2C)

3 NAD+

3 NADH3 NADHFAD

FADHFADH22

ATPATP ADP + P

(one turn)(one turn)

OAA (4C) Citrate (6C)

2 CO2


KrebsCycle

2 Acetyl CoA (2C)

6 NAD+

6 NADH6 NADH2 FAD

2 FADH2 FADH22

2 ATP2 ATP 2 ADP + P

(two turns)(two turns)

OAA (4C)Citrate (6C)

4 CO2


• Total net yield (2 turns2 turns of krebs cycle)

1. 2 - ATP (substrate-level phosphorylation)2. 6 - NADH3. 2 - FADH2

4. 4 - CO2

4. Electron Transport Chain (ETC) and4. Electron Transport Chain (ETC) andOxidative Phosphorylation (Oxidative Phosphorylation (ChemiosmosisChemiosmosis))

•• Location:Location: inner mitochondrial membrane.

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

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

InnerMitochondrialMembrane


• The H+ then move via diffusiondiffusion (Proton Motive Force) through ATP Synthase to make ATP.

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

• Each NADH converts to 3 ATP.

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


Innermembrane

Outermembrane

Innermembrane space

MatrixCristae

4. 4. ETC and Oxidative Phosphorylation ETC and Oxidative Phosphorylation ((Chemiosmosis for Chemiosmosis for NADHNADH))

NADH+ H+

ATPSynthase

1H+ 2H+ 3H+

higher Hhigher H++

concentrationconcentration

H+

ADP + ATP

lower Hlower H++


H+

(Proton Pumping)

P

E T C

NAD+2H+ + 1/2O2 H2O

Intermembrane SpaceIntermembrane Space

MatrixMatrix


4. 4. ETC ETC and and Oxidative Phosphorylation Oxidative Phosphorylation (Chemiosmosis for (Chemiosmosis for FADH2)

FADH2+ H+

ATPSynthase

1H+ 2H+

higher Hhigher H++


H+

ADP + ATP

lower Hlower H++


H+

(Proton Pumping)

P

E T C

FAD+2H+ +

1/2O2H2O

Intermembrane SpaceIntermembrane Space

MatrixMatrix


TOTAL ATP YIELDTOTAL ATP YIELD

1. 04 ATP - substrate-level phosphorylation2. 34 ATP - ETC & oxidative phosphorylation

38 ATP - TOTAL YIELD

ATPATP

Eukaryotes(Have Membranes)

• Total ATP Yield02 ATP - glycolysis (substrate-level phosphorylation)

04 ATP - converted from 2 NADH - glycolysis06 ATP - converted from 2 NADH - grooming phase

02 ATP - Krebs cycle (substrate-level phosphorylation)

18 ATP - converted from 6 NADH - Krebs cycle04 ATP - converted from 2 FADH2 - Krebs cycle36 ATP - TOTAL

Maximum ATP Yield for Cellular Respiration (Eukaryotes)

36 ATP (maximum per glucose)

Glucose

Glycolysis

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

2 ATP(substrate-levelphosphorylation)

2NADH

2NADH6NADH

KrebsCycle

2FADH2

2 ATP(substrate-levelphosphorylation)

2 Pyruvate2 Acetyl CoA

ETC and OxidativePhosphorylation

Cytosol

Mitochondria

ProkaryotesProkaryotes(Lack Membranes)(Lack Membranes)

• Total ATP Yield02 ATP - glycolysis (substrate-level phosphorylation)

06 ATP - converted from 2 NADH - glycolysis06 ATP - converted from 2 NADH - grooming phase

02 ATP - Krebs cycle (substrate-level phosphorylation)

18 ATP - converted from 6 NADH - Krebs cycle04 ATP - converted from 2 FADH2 - Krebs cycle38 ATP - TOTAL

Question:Question:

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

Catabolism of VariousCatabolism of VariousFood MoleculesFood Molecules

• Other organic molecules used for fuel.

1. Carbohydrates: polysaccharides

2. Fats: glycerol’s and fatty acids

3. Proteins: amino acids

cellular respiration - citrus...

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