Cellular Respiration

Cellular Respiration

Chapter 6

Types of Energy?????

Energy - *forms: light, heat, mechanical, chemical, electrical, sound

*potential energy = stored kinetic energy = being used

*can be transformed from one type to another – -battery - chemical to electrical -roll downhill - potential to kinetic -flip light switch –mechanical to electrical to light & heat *it is the ability to do work!

Cellular Respiration

A cellular process that releases energy from glucose (or other organic molecules) to produce energy (ATP).

C6H12O6 + 6O2 6CO2 + 6H2O (energy)glucose ATP

What respires?

Plants and Animals/all living organisms

Mitochondria

Organelle where cellular respiration takes place.

Innermembrane

Outermembrane

Matrix Cristae

ATP & ADP

ATP & ADP

Oxidation-Reduction Reactions Transfer of one or more electrons

and/or energy from one compound to another.

Two parts:1. Oxidation2. Reduction

Oxidation Reaction

The loss of electrons or energy from a compound.

Reduction Reaction

The gain of electrons or energy to a compound.

Oxidation-Reduction Reactions

• Reactions where 1 substance loses electrons &/or energy &/or hydrogen and another substance gains electrons &/or energy &/or hydrogen

• O• I• L• R• I• G

Oxidation reaction: loss of electrons &/or energy &/or hydrogenReduction reaction: gain of electrons &/or energy &/or hydrogen

Aerobic Respiration Pathway

-lots of chemical reactions –controlled by enzymes

Important patterns: *energy released –> captured by ADP to make ATP *energized H released ->captured by NAD to make NADH & H+ or captured by FAD to make FADH2

NAD is like catcher’s mitt– catches fastball/high energy H

FAD is like fielder’s mitt – catches slower ball/lower energy H

*when C atom is lost, it is released as CO2

Aerobic RespirationRespiration in the presence of free

oxygen, resulting in the complete oxidation of glucose to carbon dioxide and water as well as the release of a net of 36 ATP’s.

Potato chip = fuel!!!contains energy (potential) in chemical bonds

Burn chip – releases energy in form of light/heat can use that energy to do work

For our bodies to do work (life processes), can’t useenergy in form of heat/light …living things need energy in form of ATP

ADP = adenosine diphosphate

ATP = adenosine triphosphate GainEnergizedphosphate

loseEnergizedphosphate

ATP is the ultimate form of energy for living things!

Aerobic Respiratory Pathway

Four main parts (reactions).

1. Glycolysis (splitting of glucose)a. cytoplasm, just outside of

mitochondria.

2. Pyruvic Acid breakdowna. migration from cytoplasm to

mitochondria.

Aerobic Respiratory Pathway

3. Krebs Cyclea. mitochondria

4. Electron Transport Chain (ETC)

a. mitochondria

1. Glycolysis

Occurs in the cytoplasm just outside of mitochondria.

Two phases:A. Energy investment phase

a. 2 ATP activation energyB. Energy yielding phase

a. 4 ATP produced

1. Glycolysis

A. Energy Investment Phase:

Glucose (6C)

(2 - 3C)

2 ATP - used0 ATP - produced0 NADH & H+ - produced

2ATP

2ADP+ P

C-C-C-C-C-C

C-C-C C-C-C

2

1. Glycolysis

B. Energy Yielding Phase

(2 - 3C)

Pyruvate (2 - 3C)or Pyruvic Acid (PYR)

0 ATP - used4 ATP - produced2 NADH & 2H+ - produced

4ATP

4ADP+4 P

C-C-C C-C-C

C-C-C C-C-C

PGAL PGAL

(PYR) (PYR)

1. Glycolysis

Total Net Yield

2 - 3C-Pyruvic acid (Pyruvate)2 – ATP (Stored Chemical Energy)

(4 ATP produced-2 used as Activation Energy)

2 – NADH & H+

Glycolysis

2. Pyruvic Acid Breakdown Occurs when Oxygen is present

(aerobic). 2 Pyruvic Acid (3C) molecules are

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

CytoplasmCCC

2 Pyruvic

2 CO2

2 Acetyl CoAC-C

2NADH & 2H+ 2 NAD+

Matrix

2. Pyruvic Acid Breakdown End Products:

2 – NADH2 – H+2 - CO2 (Released as waste)2 - Acetyl CoA (2C)

*Enters Kreb Cycle

Pyruvic

Acid

Breakdown

3. Krebs Cycle (Citric Acid Cycle)

Location: mitochondria Acetyl CoA (2C) bonds to Oxalacetic

acid (4C - OAA) to make Citric acid (6C).

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

MitochondrialMatrix

3. Krebs Cycle (Citric Acid Cycle)

KrebsCycle

1 Acetyl CoA (2C)

3 NAD+

3 NADH & 3H+

FAD

FADH2

ATP ADP + P

(one turn)

OAA (4C) Citric acid (6C)

2 CO2

3. Krebs Cycle (Citric Acid Cycle)

KrebsCycle

2 Acetyl CoA (2C)

6 NAD+

6 NADH & 6H+

2 FAD

2 FADH2

2 ATP 2 ADP+2 P

(two turns)

OAA (4C)Citrate (6C)

4 CO2

Krebs

Cycle

3. Krebs Cycle (Citric Acid Cycle)

Total net yield (2 turns of krebs cycle)

1. 2 - ATP 2. 6 – NADH & H+

3. 2 - FADH2

4. 4 - CO2

4. Electron Transport Chain (ETC)

Location: mitochondrial. Uses ETC and ATP Synthase (enzyme)

to make ATP. ETC pumps H+ (protons) across

innermembrane.

InnerMitochondrialMembrane

4. Electron Transport Chain (ETC)

Innermembrane

Outermembrane

Innermembrane space

MatrixCristae

4. Electron Transport Chain (ETC)

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).

4. ETC and Chemiosmosis for NADH

NADH+ H+

ATPSynthase

1H+ 2H+ 3H+

higher H+

concentration

H+

ADP + ATP

lower H+

concentration

H+

Proton (H+) Pumping

P

E T C

NAD+2H+ + 1/2O2 H2O

Intermembrane Space

Matrix

InnerMitochondrialMembrane

4. ETC and Chemiosmosis for FADH2

FADH2

+ H+

ATPSynthase

1H+ 2H+

higher H+

concentration

H+

ADP + ATP

lower H+

concentration

H+

Proton (H+) Pumping

P

E T C

FAD+2H+ +

1/2O2H2O

Intermembrane Space

Matrix

InnerMitochondrialMembrane

Electron

Transport

Chain

2 e-

e- s

+ 2 H+

NAD+ (recycled)

TOTAL ATP YIELD

1. 04 ATP - Phosphorylation2. 34 ATP - ETC & oxidative

phosphorylation 38 ATP - TOTAL YIELD

ATP

Eukaryotes(Have Membranes)

Total ATP Yield02 ATP - glycolysis (substrate-level

phosphorylation)04 ATP - converted from 2 NADH –

glycolysis 06 ATP - converted from 2 NADH – pyruvic

acid breakdown phase02 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 Oxidative Phosphorylation

CytosolMitochondria

Prokaryotes(Lack Membranes)

Total ATP Yield02 ATP - glycolysis (substrate-level

phosphorylation)06 ATP - converted from 2 NADH -

glycolysis06 ATP - converted from 2 NADH – pyruvic

acid breakdown phase02 ATP - Krebs cycle (substrate-level

phosphorylation)18 ATP - converted from 6 NADH - Krebs

cycle04 ATP - converted from 2 FADH2 - Krebs

cycle38 ATP - TOTAL

Question: In addition to glucose, what other food molecules are used in Cellular

Respiration?

Catabolism of VariousFood Molecules Other organic molecules used for

fuel.1. Carbohydrates:

polysaccharides2. Fats: glycerol’s and fatty acids3. Proteins: amino acids

Fermentation/Anaerobic Respiration Occurs in cytoplasm when “NO

Oxygen” is present (called anaerobic).

Remember: glycolysis is part of fermentation.

Two Types:1. Alcohol Fermentation2. Lactic Acid Fermentation

Alcohol Fermentation

Plants and Fungi beer and wine

glucose

Glycolysis

CCCCCC

CCC

2 Pyruvic acid

2ATP2ADP+ 2

2NADH & 2H+

P

2 NAD+

CC

2 Ethanol2CO2

released

2NADH 2 NAD+

Alcohol Fermentation

End Products: Alcohol fermentation

2 - ATP (substrate-level phosphorylation)2 - CO2

2 - Ethanol’s

Lactic Acid Fermentation

Animals (pain in muscle after a workout).

2 Lactic acid

2NADH 2 NAD+

CCC

Glucose

GlycolysisCCC

2 Pyruvic acid

2ATP2ADP+ 2

2NADH & H+

P

2 NAD+

CCCCCC

Lactic Acid Fermentation

End Products: Lactic acid fermentation

2 - ATP (substrate-level phosphorylation)2 - Lactic Acids

THEEND!!