6H2O + 6CO2 + ATPC6H12O6 + 6O2

Cellular RespirationHarvesting Chemical

Energy

Recycling of Molecules for energy production

OVER VIEW OF CELLULAR

RESPIRATION

Glycolysis Pyruvate

Oxidation

Krebs Cycle

ETC

2 ATP 2 NADH 2 NADH

6 NADH

2 FAD

2 ATP

34 ATP

IN THE PRESENCE OF OXYGEN

IN THE ABSENCE OF OXYGEN

Where do the reactants and products go?

c6H12O6 + 6O2 38 ATP + 6H2O + 6CO2

Glucose Cut up in glycolysisOxygen Reactant in ETCWater Product of ETCCO2 Product of Krebs Cycle38 ATP Product from Glycolysis (2), Krebs(2),

ETC(34)

Copyright Cmassengale

Chemical Structure of ATP

3 Phosphates Ribose

Sugar

Adenine Base

What Does ATP Do for You?

It supplies YOU with ENERGY!

Copyright Cmassengale

By breaking the high- energy bonds between the last two phosphates in ATP Copyright Cmassengale

How Do We Get Energy From ATP?

HYDROLYSIS (Adding H2O)

Copyright Cmassengale

What is the Process Called?

H2O

Copyright Cmassengale

The ADP-ATP Cycle

ATP-aseATP Synthetase

Cellular respiration is a Redox reaction as the transfer of one or more electrons from one reactant to another occurs

Oxidation is the loss of electronsReduction is the addition of electrons.Because the electron transfer requires a

donor and an acceptor, oxidation and reduction always go together.

REDOX Reactions

The breakdown of glucose is exergonic. This means that the products store less energy than the reactants

The basic purpose of respiration

6H2O + 6CO2 + ATPC6H12O6 + 6O2

Energy released

Energy re-captured

So where does this released energy go?

Electrons are shuffled around and passed through several cycles to eventually be used to bond ADP and Pi to form ATP

The basic version of how it works…

Where do the electrons from Glucose go??

NAD+ (nicotinadenine dinucleotide) acts as the energy carrier

NAD+ is a coenzyme

It’s Reduced to NADH when it picks up two electrons and one hydrogen ion

Copyright Cmassengale

Are There Any Other Electron Carriers?

YES! Another Coenzyme!

FAD+ (Flavin adenine dinucleotide)

Reduced to FADH2

Copyright Cmassengale

Other Cellular Respiration Facts

Metabolic Pathway that breaks down carbohydrates

Process is Exergonic as High-energy Glucose is broken into CO2 and H2O

Process is also Catabolic because larger Glucose breaks into smaller molecules

Copyright Cmassengale

Direct Phosphorylation

Overall Equation for Cellular Respiration

6CO2 + 6H20 + e- + 36-38ATP’s

C6H12O6 + 6O2

YIELDS

Copyright Cmassengale

Four Stages of Cellular Respiration

Glycolysis – cutting glucose to make pyruvate

Pyruvate Oxidation – cutting pyruvate to make CoA

Krebs Cycle - making NADH and FADH

Electron Transport – Converting to ATP

Glycolysis

Splits a glucosemolecule into 2 - 3 Carbon molecules calledPYRUVATE.

Input: C6H12O6, (2ADP, 2Pi, 2NAD)products: 2H2O, 2 pyruvate, (2 ATP, 2NADH )

C-C-C-C-C-C

C-C-C C-C-C

Glycolysis

Pyruvate Oxidation

The pyruvate looses acarbon leaving the 2 carbon molecule Acetyl CoA

CC

CO2

Input: Pyruvate + O2

products: CO2, Acetyl CoA and 2 NADH

C-C-C + O2 ------ > C-C + CO2

Glycolysis SummaryTakes place in the CytoplasmAnaerobic (Doesn’t Use Oxygen)Glucose split into two molecules of Pyruvate or Pyruvic AcidRequires input of 2 ATPProduces 2 NADH and 4 ATPPyruvate is oxidized to Acetyl CoA and CO2 is removed

Copyright Cmassengale

Glycolysis Diagram

Copyright Cmassengale

BANK BALANCEATP NADH FAD

Glycolysis + Pyruvate oxidation

2 4 0

The Krebs Cycle “a bit of chemical magic happens”

Inputs: Acetyl CoA, H2O, (FAD, NAD, ADP, Pi)Products: CO2 ATP, NADH, FADH

Krebs Cycle SummaryRequires Oxygen (Aerobic)Cyclical series of oxidation reactions that

give off CO2 and produce one ATP per cycle

Turns twice per glucose moleculeProduces two ATP Takes place in matrix of mitochondria

Copyright Cmassengale

Krebs Cycle SummaryEach turn of the Krebs Cycle also produces 3NADH, 1FADH2, and 2CO2

Therefore, For each Glucose molecule, the Krebs Cycle produces 6NADH, 2FADH2, 4CO2, and 2ATP

Copyright Cmassengale

BANK BALANCEATP NADH FAD

Glycolysis + Pyruvate oxidation

2 4 0

Krebs cycle

2 6 2

Electron Transport

The mitochondria hastwo membranes--theouter one and the innermembrane which isconvoluted. The H+ which are brought tomitochondria accumulatebetween these two membranes.

matrix

H+

H+

H+

H+ H+H+

outer membrane

inner membrane( ATP synthetase)

The matrix is a protein rich solution which contain theenzymes which run electron transport.

ATP SYNTHETASE is the enzyme which is responsible formaking ATP.

MitochondriaH+

H+NADH+

Electron Transport Chain Summary

34 ATP ProducedH2O ProducedOccurs Across Inner Mitochondrial

membraneUses coenzymes NAD+ and FAD+ to

accept e- from glucose1 x NADH can create 3 ATP’s1 x FADH2 can create 2 ATP’s

Copyright Cmassengale

ELECTRON TRANSPORT CHAIN ANIMATION

http://www.science.smith.edu/departments/Biology/Bio231/etc.html

The electrons are passedback and forth across themembrane where their energyis gradually decreased and usedto transport H+ through the membrane. Oxygen is the finalelectron acceptor and it joins withthe H+ to produce H2O.

If there is no oxygen, the electron chain cannot continuebecause there is no way to release electrons (nothing to accept the H+ atoms the cross the membranes)

electrons

Inputs: NADH, FADH, H+, ADP, Pi, O2

Outputs: NAD+, ATP, FAD, H2O

INPUT AND OUTPUT OF ETC

Products of the Electron Transport Chain

34 ATP

Water

+

BANK BALANCEATP NADH FADH

Glycolysis + Pyruvate oxidation

+ 2 +4 0

Krebs cycle

+ 2 + 6 + 2

ETC +34 - 10 - 2

Total +38 0 0

The ETC withdraws NADH and FADH 8 NADH to create 24 ATP 2 FADH to create 4 ATP

glycolysis

NADH carries electrons to ETC

prep

Krebs Electron Transport

chain

ATP

2 2 NADH

2 NADH

What happens when there is no oxygen to accept the electrons?

Only the process of glycolysis is carried out and lacticacid is produced in the muscles. The body cannottolerate much lactic acid and it must eventually be converted in the liver to pyruvate.

results in muscle soreness

Alcoholic FermentationSome organisms carry out alcoholic fermentation. This wasdiscovered by Louis Pasteur in his study of the chemistryof wines. Yeasts break down the sugars in the juice topyruvate by glycolysis, then the pyruvate is dismantled toyeild CO2 and ETHANOL. If the fermentation continuesuntil all the sugar is used, a dry wine is produced. Iffermentation is stopped before all the sugar is used, thena sweet wine is produced.

Same process, different products