ADP, ATP and ADP, ATP and Cellular Cellular

RespirationRespiration

VOCABUALRYVOCABUALRY

2/25 – ATP2/25 – ATP

2/27 – pigment2/27 – pigment

I Can……I Can……

2/25 – Describe purpose of 2/25 – Describe purpose of cellular respiration.cellular respiration.

2/27 – explain why plants 2/27 – explain why plants look green.look green.

THE FOOD WEB

Living things need energy to Living things need energy to survive and function.survive and function.

You get the energy you need from You get the energy you need from the food you eat.the food you eat.

Where does that energy come Where does that energy come from?from?

Sun Sun Plants Plants You !!! You !!!

22

ATP

Making energy!Use the materials

from our food

The pointis to make

ATP!

What Does ATP Do for You?What Does ATP Do for You?

It supplies YOU withIt supplies YOU with ENERGY!ENERGY!

What Is ATP?What Is ATP?A molecule that carries the A molecule that carries the energy used by all cellsenergy used by all cells

Adenosine TriphosphateAdenosine Triphosphate

Organic molecule containing Organic molecule containing high-energy Phosphate bondshigh-energy Phosphate bonds

Copyright Cmassengale

ATP: Energy StorageATP: Energy StorageWHAT IS ATP? WHAT IS ATP? Universal Energy Universal Energy

MoleculeMolecule The cellThe cell’’s s ““Energy Energy

BankBank”” Adenosine Adenosine

Triphosphate (ATP)Triphosphate (ATP) Consist of Consist of

a sugar called a sugar called riboseribose

N containing N containing AdenineAdenine

Three phosphate Three phosphate groupsgroups

44

ATP

Fueling the body’s economy eat high energy organic molecules

food = carbohydrates, lipids, proteins, nucleic acids

Make in CELLULAR RESPIRATION!!

Whoa! Hot stuff!

When is ATP Made in the When is ATP Made in the Body?Body?

During a Process During a Process called called Cellular Cellular RespirationRespiration that that takes place in takes place in both both Plants & Plants & Animals in the Animals in the mitochondriamitochondria

Copyright Cmassengale

How does ATP transfer energy?

PO–

O–

O

–O PO–

O–

O

–O PO–

O–

O

–O7.3

energy+PO–

O–

O

–O

ATP ADP

BONDS ALWAYS CONTAIN ENERGY!!!

WHEN YOU BREAK A BOND ENERGY IS RELEASED!!

FORMING A BOND TAKES ENERGY!!

ADPATP

How Do We Get Energy From How Do We Get Energy From ATP?ATP?

By breaking the By breaking the high- energy high- energy bonds between bonds between the the last two last two phosphates in phosphates in ATPATP

How Does ATP Work? The bonds between phosphate groups can be

broken by hydrolysis which produces energy!!! ATP has 3 phosphate groups The bond to the

third bond is easily broken. When the third bond is broken, energy is released. Becomes ADP – no energy!!

How Does ATP Work? So what? Energy is stored in these bonds. So? The breaking of the chemical bond releases the

energy

ATP + H2O→ ADP + P + ENERGY ATP is made in photosynthesis and respiration!!!

ATP (adenosine triphosphate) is a a molecule that carries energy that cells can use.

ATPATP

Adenine Ribose 3 Phosphate groups

55

When the energy is used theWhen the energy is used the ATP ATP is converted into is converted into ADPADP

Partiallychargedbattery

Fullychargedbattery

PP

ADPADP ATPATP

CLIP

The Bonds between the phosphate groups in ATP are VERY HIGH ENERGY.When a phosphate group is removed-energy is released

66

What is the Process Called?What is the Process Called?HYDROLYSIS (Adding HHYDROLYSIS (Adding H22O)O)

H2O

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How Does That Happen?How Does That Happen?

An An Enzyme!Enzyme!

Copyright Cmassengale

How is ATP Re-Made?How is ATP Re-Made?

The reverse of the previous process The reverse of the previous process occurs.occurs.

Another Enzyme Another Enzyme is used!is used!

ENERGY IS ENERGY IS NEEDEDNEEDED

ATP ATP SynthetaseSynthetaseCopyright Cmassengale

The ADP-ATP CycleThe ADP-ATP Cycle

ATP-ATP-asease

ATP ATP SynthetaSynthetasese

Copyright Cmassengale

Photosynthesis and Photosynthesis and Cellular RespirationCellular Respiration

THE SUN: WHY IS IT THE SUN: WHY IS IT IMPORTANT?IMPORTANT?

Source of light energySource of light energySource of heat energySource of heat energyGravitational attractionGravitational attraction

Source of radiationSource of radiationDay and nightDay and night

Source of all energy(electricity)Source of all energy(electricity)

Source of food for all organisms!!!!Source of food for all organisms!!!!

Role of SUN in photosynthesis?Role of SUN in photosynthesis? Role of photon?Role of photon? Why are pigments important? JOB?Why are pigments important? JOB? Name the main pigment – location?Name the main pigment – location? Name of other pigments – Roles?Name of other pigments – Roles? Why do leaves change color in fall?Why do leaves change color in fall? What do plants use to start photosynthesis?What do plants use to start photosynthesis? Why do plants have different pigments?Why do plants have different pigments? Why aren’t plant black?Why aren’t plant black? Why do plants appear green?Why do plants appear green? What color of the light spectrum do plants use?What color of the light spectrum do plants use?

Name of all the waves received from the Sun?

Name of the part that plants use. Purpose of photosynthesis. END GOAL?

Light Energy(photons) Harvested by Plants & Other Photosynthetic

Autotrophs

6 CO2 + 6 H2O + light energy → C6H12O6 + 6 O2

Sunlight & Plants - ??????Sunlight & Plants - ??????

Travels in waves.Travels in waves. Waves contains packages of energy called Waves contains packages of energy called

photons. Plants traps energy in photons. Plants traps energy in pigments.pigments.

Sunlight energy is called Sunlight energy is called electromagneticelectromagnetic

Energy. Energy.

Electromagnetic spectrum Electromagnetic spectrum – full range of – full range of wavelengths received from the Sun.wavelengths received from the Sun.

SUNSUN’’S SPECTRUMS SPECTRUM

Electromagnetic Spectrum and Visible Light

Gammarays X-rays UV

Infrared & Microwaves Radio waves

Visible light

Wavelength (nm)

Pigment and LightSun’s energy travels as light(photon). We see sunlight as “white light” (ROYGBIV).Plant gather the Sun’s energy(photons) with light-absorbing molecules called PIGMENTS.Pigments: photosynthetic organisms capture energy(photons) using pigments.

Plants are absorbing all colors except green as photons to power photosynthesis!!!!

WHYWHY ARE ARE PLA PLANTS NTS GREGREEN?EN?

Gammarays

X-rays UV Infrared Micro-waves

Radiowaves

Visible light

Wavelength (nm)

Plants are green BECAUSE!!Plants are green BECAUSE!!

Chlorophyll a & b absorb all Chlorophyll a & b absorb all colors but green in the colors but green in the thylakoid membrane as thylakoid membrane as photons to jump start photons to jump start photosynthesis. They use photosynthesis. They use all the colors but green.all the colors but green.

Sunlight minus absorbed Sunlight minus absorbed wavelengths or colors wavelengths or colors equals the apparent color equals the apparent color of an object.of an object.

The feathers of male cardinals are loaded with carotenoid pigments. These pigments absorb some wavelengths of light and reflect others.

Reflected light

.

LightReflected

light

Absorbedlight

Transmittedlight

Chloroplast

THE COLOR OF LIGHT SEEN IS THE COLOR NOT ABSORBED

Why Not Black?

TOO MUCH ENERGY!!!!!!!

– Chlorophyll a – green pigments in plants and bacteria MAIN PIGMENT!!!!

Accessory Pigments – pigments that pass photons to chlorophyll a

– Chlorophyll b in green algae– Carotenoids – orange, red, yellow when chloroplast

die in plants. Chlorophyll breaks down first in the fall so we see these colors.

– Xanthophyll – yellow pigments in diatoms(protists)

Figure 7.7

Why should a plant have a Why should a plant have a variety of pigments?variety of pigments?

MORE ABSORPTION – but MORE ABSORPTION – but not TOO much!!!not TOO much!!!

Goldilocks effectGoldilocks effect

MORE PIGMENTS;MORE MORE PIGMENTS;MORE ABSORPTION!!!!ABSORPTION!!!!

..

b

a

1919

Different pigments absorb light differently

Where does Where does photosynthesis photosynthesis take place?take place?

1212

Where does photosynthesis Where does photosynthesis occur?occur?

CHLOROPLAST!!CHLOROPLAST!! BUT there are different parts of the BUT there are different parts of the

choroplasts you must know!choroplasts you must know!

Where are pigments Where are pigments Located???Located???

The location and structure of chloroplasts

LEAF CROSS SECTION MESOPHYLL CELL

LEAF

Chloroplast

Mesophyll

CHLOROPLAST Intermembrane space

Outermembrane

Innermembrane

ThylakoidcompartmentThylakoidStroma

Granum

StromaGrana

Section 23-4

Epidermis

Stomata

Guardcells

The Internal Structure of a The Internal Structure of a LeafLeaf

CO2 enters through the stomata

Chloroplasts

CO2

Goes in

1414

Leaf StructureLeaf StructurePhotosynthesis Location:Photosynthesis Location:

The leaves of plants:The leaves of plants:

stomata – holesstomata – holes

On the bottom of leaves.On the bottom of leaves.

StomataCellChloroplast

CO2

Goes in

1313

Chloroplast Chloroplast PicturePicture

1717

Chloroplast Structure

Thylakoids:Thylakoids: flat compartments in the flat compartments in the chloroplast that contains plant pigments. chloroplast that contains plant pigments. LIGHT DEPEDENT REACTION occurs here.LIGHT DEPEDENT REACTION occurs here.GranaGrana: are stacks of thylakoids.: are stacks of thylakoids.StromaStroma: fluid that is all around the grana : fluid that is all around the grana inside the chorplast. LIGHT INDEPENDENT inside the chorplast. LIGHT INDEPENDENT REACTION occurs here.REACTION occurs here.

Parts of the Chloroplasts

Why are Chloroplast Important?

The chloroplasts contain the PIGMENTSthat absorb the Sun’s energy as photons and use this energy to excite electrons which power photosynthesis. To break apart water and carbon dioxide, you must have energy!!!!

LETS START AT LETS START AT THE THE

BEGINNING!!!!!!!BEGINNING!!!!!!!

• Almost all plants are photosynthetic autotrophs, as are some bacteria and protists– Autotrophs generate their own organic matter through

photosynthesis– Sunlight energy is transformed to energy stored in the

form of chemical bonds

(a) Mosses, ferns, andflowering plants

(b) Kelp

(c) Euglena (d) Cyanobacteria

THE BASICS OF PHOTOSYNTHESIS

Photosynthesis: Products Photosynthesis: Products &Reactants&Reactants

CO2 + H2OChloroplast

Light Energy

Glucose & O2

2020

SUNSUN

Where does each reactant enter the

plant??? 2828

Photosynthesis is the process by which autotrophic organisms use light energy to make sugar and oxygen gas from carbon dioxide and water

AN OVERVIEW OF PHOTOSYNTHESIS

Carbondioxide

Water Glucose Oxygengas

PHOTOSYNTHESIS

Overview of Photosynthesis

Step 1 – Light dependent reaction(depends on Light)Traps the sunlight and energy is moved along

the thylakoid membrane.Water is broken in to O and H by the electrons that

are in ATP and NADPH required for dark reaction.

Oxygen given off as waste.Photosystem I and photosystem II - pigments

Step 2 – Dark reaction(Calvin Cycle)Carbon Dioxide now is added to cycle to build

glucose.Uses ATP and electrons from light reaction to make glucose.

Photosynthesis

Occurs in two Occurs in two StepsSteps

Light dependent Reaction

Light indedenpent/ Calvin Cycle

Oxygen

ATP

NADPH

Thylakoid

Membrane

Glucose Stroma

Produces

Produces

Occurs (location)

2626

Occurs (location)

6CO2 + 6H2O + energy from sunlight → C6H12O6 + 6O2

Photosystems: cluster of chlorophyll and proteins absorb the sun’s energy and generate the high energy electrons that are passed to the electron carrier molecules.

Their energy ends up in ATP and NADPH

Electron transport chains and Electron transport chains and photosystemsphotosystems

High Energy Electrons and Molecules

Once the sun’s energy has been trapped and excited an electron, what happens to it?Electron Carrier: a molecule that picks up the electron and uses this energy to break apart bonds.Examples of electron carriers: NADP and ATPNADP captures two electrons of H and becomes NADPH.ADP becomes ATP!!!

Electron Transport Chain

When the electrons are excited from the light reaction, they are passed along the membrane through the protein pumps. They passed from Photosystem I to photosystem II.

Step 1:Step 1: Light Dependent Light Dependent ReactionReaction. .

Energy capturedEnergy captured from from Sunlight.  Sunlight. 

HH22O is splitO is split into H into H++, electrons, , electrons,

& Oxygen (O & Oxygen (O22).  ).  The The OO22 diffuses out diffuses out

of the Chloroplasts. of the Chloroplasts.

MADE:MADE: OO22 , , ATP & ATP & NADPH NADPH..

Takes place:Takes place: Thylakoid Thylakoid

2323The light reaction is the photo part of photosynthesis.

PhotosynthesisPhotosynthesisStep 1 – Light Dependent ReactionThe light reactions convert solar energy to chemical energy. Takes place in thylakoid membrane - photosystems.Photosystem II and electron transport1. Pigments absorb photons. Splits water.2. Energy as electrons is moved along the membrane(electron transport chain) 3. Water is split into H, electrons, and O. O released as waste through stomata.4. H is pumped into the membrane to make ATP through ATP synthase.

PhotosynthesisPhotosynthesisPhotosystem IPhotosystem I

1. Electrons from photosytem II is moved 1. Electrons from photosytem II is moved along the membrane to photosystem I.along the membrane to photosystem I.

2. Chlorophyll(pigments) continue to adsorb 2. Chlorophyll(pigments) continue to adsorb sunlight and free electrons.sunlight and free electrons.

3. Electrons are added to NADPH which is 3. Electrons are added to NADPH which is the energy carrier for the rest of the energy carrier for the rest of photosynthesis.photosynthesis.

4. The electrons and H are pumped though a 4. The electrons and H are pumped though a channel as part of an enzyme ATP channel as part of an enzyme ATP synthase to make ATP.synthase to make ATP.

The O2 liberated by photosynthesis is made from the oxygen in water (H+ and e-)

Plants produce OPlants produce O22 gas by splitting H gas by splitting H22OO

Summary of Light-dependent Reaction

Energy is captured from sunlight and transferred to electrons(electron transport chain).Water molecule pulled apart to provide H ions.The ions are used to make ATP and NADPH.Need: sunlight and water Produce: energy carrying molecules and oxygen(waste).

Summary—Light Dependent Reactions

a. Overall inputphotons, H2O.

b. Overall output ATP, NADPH, O2.

LightChloroplast

Lightreactions

Calvincycle

NADP

ADP+ P

1

AN OVERVIEW OF PHOTOSYNTHESIS

–The Chemical Energy Stored in ATP and NADPH is used to make Glucose using CO2.

–This is a light independent reaction.

–MADE:MADE: Glucose–Takes place:Takes place: Stroma

Step 2:Step 2: Light IndependentIndependent Reaction (CALVIN CYCLE).

2244

SunlightWater

Oxygen

The Calvin cycle is the synthesis part of photosynthesis.

ATP

NADPH

Step 1:Step 1: Light Light Dependent Dependent ReactionReaction

This process is known as carbon

fixation.

• Step 2 – Light Independent Reaction – CALVIN CYCLE Occurs in the stroma.

• The Calvin cycle makes sugar from carbon dioxide

1.ATP generated by the light reactions provides the energy for sugar synthesis

2.The NADPH produced by the light reactions provides the electrons for the reduction of carbon dioxide to glucose. Carbon Dioxide is built to make a 6 carbon sugar called glucose.

– END GOAL – to break carbon dioxide down and combine into glucose!!! Need energy to do this!! That is why ATP and NADPH was made!!

AN OVERVIEW OF PHOTOSYNTHESIS

Light Independent Reaction Overview1. Carbon dioxide added:Carbon Dioxide enters the plant from the atmosphere. Bonds with a 5-carbon sugar.2. Three-carbon molecules formed: ATP and NADPHuse enzymes in the stroma to split the six carbon into 2 3 carbon sugars. Its unstable!!!3. One Three-carbon molecules exit: to become glucose4. Other Three-carbon molecules recycled: Energy from ATP Change 3carbon molecules back into 5 carbon to start thecycle over again. IT TAKES 2 CYCLES TO MAKE 1 GLUCOSE!

Overview Calvin Cycle

In put: ATP, NADPH, and Carbon dioxideOutput: GLUCOSE!!

The end goal – Make glucose from the SUN!!

STOMATA

http://cronodon.com/BioTech/Plant_Transport.html

The production of ATP

Thylakoidcompartment(high H+)

Thylakoidmembrane

Stroma(low H+)

Light

Antennamolecul

es

Light

ELECTRON TRANSPORT

CHAIN

PHOTOSYSTEM

II

PHOTOSYSTE

M I

ATP

SYNTHASE

Harvesting Chemical Energy

Energy enters food chains (via autotrophs) we can look at how organisms use that energy to fuel their bodies.

Plants and animals both use products of photosynthesis (glucose) for metabolic fuel

Heterotrophs: must take in energy from outside sources, cannot make their own e.g. animals

Cellular Respiration

30

Cellular Respiration Overview:Cellular Respiration Overview: Plants are producers and make glucose by

the process of photosynthesis. Heterotrophs breakdown glucose for energy. There are two important ways a cell can

harvest energy from food: fermentation and fermentation and cellular respiration. cellular respiration.

32

36

Cellular RespirationCellular RespirationPurpose

1. Converts energy in the bonds of glucose into ATP.

2. Many steps that allows energy to be slowly released. OR you would explode!!

3. Slow breakdown of glucose yields 36 or 38 ATPS

31

How Do You Make ATP?

ATP synthase on the membrane of the cristae.

The electrons are sent to the Electron Transport

Chain where they help to make ATP through ATP synthase.

How do we make ATP?

Just like in photosynthesis. ATP is made by pumping H across ATP synthase to attach a P onto ADP. This is the goal of cellular respiration.

MAKE 38 ATP from each glucose molecule!!

NAD and FAD – Energy carriers* Photosynthesis use the electron carrier – NADP•Cellular respiration uses – NAD•FAD – also an energy carrier or electron carrierCarry to ATP synthenaseTHEY CARRY THE H+ TO THE CRISTAE TOBE PUMPED ACROSS TO MAKE ATP!!

Parts of the Mitochondria

1. Cristae – Fold of the mitochondria

Location of the ETC that makes ATP.

Folded to make more surface area for more ATP.

2. Matrix: Space in mitochondria where the KREB cycle occurs.

Mitochondria AnatomyMitochondria Anatomy

35

Steps 2 & 3 Occur in the Mitochondria 2 membranesOwn ribosomesOwn DNA

4 Steps4 Steps.

Step 1: Glycolysis Step 1: Glycolysis CYTOPLASMCYTOPLASMANAEROBIC OR AEROBIC?ANAEROBIC OR AEROBIC?CELLULAR RESPIRATIONCELLULAR RESPIRATIONStep 2 – TransitionStep 2 – Transition

Step 3: Krebs Cycle- Step 3: Krebs Cycle- MATRIXMATRIX Step 4: ETC - CRISTAEStep 4: ETC - CRISTAE

Cellular Respiration

Glycolysis – Occurs before Cell. Resp. TRANSITIONAL Krebs Cycle (Citric Acid Cycle) Electron Transport Chain (ETC)Glucose

Glycolysis Krebs cycle

Electrontransport

Fermentation (without oxygen)

Alcohol or lactic acid

In the presence of Oxygen:In the presence of Oxygen:Step 2:Step 2: Krebs CycleStep 3:Step 3: Electron Transport

Happens in the MitochondriaMitochondria

Starts with PyruvatePyruvate.Pyruvate moves into

the mitochondria and is broken down into

COCO22,,HH22OO && ATPATP.

36

Stage Location Products Summary

Glycolysis cytoplasm Pyruvate

2 ATP

Breaks glucose into 3 C called pyruvate

Transition matrix Acetyl Co -A Breaks pyruvate into 2 carbon called Acetyl Co -A

Kreb or Citric acid

matrix FADH, NADH, ATP

Breaks bonds traps energy and electrons into energy carriers

ETC Cristae membrane

36 ATP Transport H+ protons across membrane to create a gradient. H+ pumped across ATP synthase to make ATP

FlowchartSection 9-2

Glucose(C6H1206)

+Oxygen

(02)

GlycolysisKrebsCycle

ElectronTransport

Chain

Carbon Dioxide

(CO2)+

Water(H2O)

+ATP

Cellular Respiration

Glucose

To the electron transport chain

Figure 9–3 GlycolysisGlycolysis:

Step 1

2 Pyruvic acid

Glycolysis

Glyco = glucose Lysis = break down LOCATION: Occurs in the cytoplasm This stage occurs in BOTH aerobic and

anaerobic respiration Glucose breaks down into 2 pyruvate (2 ATP are

also made) – Glucose is a 6-carbon sugar – Pyruvate is a 3-carbon molecule (there are

two of them)

Citric Acid Production

Figure 9–6 The Krebs CycleSection 9-2

Mitochondrion

Carbon Oxygen Cycle

Relationship between Photosynthesis and Cellular Respiration

The products on one are used for the other to produce ATP from the Sun!Creates the Carbon- Oxygen Cycle!!!

Glucose

Glycolysis Krebs cycle

Electrontransport

Fermentation (without oxygen)

Alcohol or lactic acid

Go to Section:

With oxygen

36

Cellular Respiration Overview

Transformation of chemical energy in food into chemical energy cells can use: ATP

These reactions proceed the same way in plants and animals. Process is called cellular respiration

Overall Reaction:– C6H12O6 + 6O2 → 6CO2 + 6H2O

Overall Reaction

C6H12O6 + 6O2 → 6CO2 + 6H2O + 38 ATP Overall this is a three stage process1. Glycolysis: before cellular respiration

• Occurs in the cytoplasm• Glucose is broken down

2. Krebs Cycle• Breaks down pyruvate into CO2• Occurs in mitochondrial matrix

3. Electron Transport Chain• ATP is synthesized - Occurs in mito membrane

Cellular Respiration Overview

Breakdown of glucose begins in the cytoplasm: the liquid matrix inside the cell

After glycolysis, life diverges into two forms and two pathways– Anaerobic cellular respiration (aka fermentation) No

oxygen – Aerobic cellular respiration I Oxygen needed!!

Step 1: GlycolysisStep 1: GlycolysisMeans Means ““Splitting Splitting

GlucoseGlucose””

GlycolysisGlycolysis starts with starts with GlucoseGlucose..

34

–Glucose is broken downGlucose is broken down into 2 molecules into 2 molecules calledcalled Pyruvate Pyruvate (aka pyruvic acid(aka pyruvic acid )..

–Happens in theHappens in the CytoplasmCytoplasm..–Clip•Glycolysis does not

need oxygen!

Citric Acid Production

Figure 9–6 The Krebs CycleSection 9-2

Mitochondrion

Steps of Glycolysis

1.Two ATP molecules are used to energize a glucose molecule. 2. Glucose is split into 2 3 carbon molecules. Enzymes rearrange the molecules.3. Electrons are transferred to NADP. The carbon molecules are converted to pyurate which enters cellular respiration.

Locatiom: Cytoplasm NO O2 required Energy Yield net gain of 2 ATP at the

expense of 2 ATP 6-C glucose TWO 3-C pyruvates Free e- and H+ combine with organic ion

carriers called NAD+ NADH + H+

(nicotinamide dinucleotide)Used in ETC. Hydrogen attached to water.

Glycolysis

Glycolysis Reactants and Products

Reactants 1 glucose Enzymes are needed 2 ATP are needed to start

Products 2 Pyruvates (go to next

step) 4 ATP (2 are gained) 2 NADH (go to ETC)

Really 10 steps with 10 different enzymes involved.

•OXYGEN PRESENT - RELEASES CHEMICAL ENERGY FROM SUGARS AND OTHER CARBON-BASED MOLECULE * Convert to NADH, FADH, AND ATP then TO MAKE ATP WHEN OXYGEN IS PRESENT!!!!

NO OXYGEN – FERMENTATION!!!!

Cellular Respiration

ANAEROBIC VS. AEROBIC

Anaerobic – no oxygen present fermentation or lactic acid can be formed. No oxygen then no cellular respiration.Aerobic –oxygen present. If oxygen is present , then cellular respiration can occur. KREB CYCLE & ETC

Krebs Cycle

TRANSITION - Matrix

Pyruvate becomes a 2 carbon molecule called Acetyl Co-A. It goes to the Kreb Cycle.

Main Goals of Krebs Cycle

Break down Acetyl Co – A into high energy electrons(NADPH and FADH) to molecules that can carry them to the electron transport chain.

* Form some ATP molecules.

Krebs Cycle- MATRIX

Acetyl Co – A enters mitochondria. In the innermost layer of mitochondria or the MATRIX pyruvic acid are broken down into carbon dioxide and acetyl CoA molecules.

Acetyl- CoA combines with 4 carbon compounds forming a 6 carbon molecule citric acid. Energy is released by breaking and reforming these bonds.

Kreb Cycle

1. Pyruvate broken down 2. Coenzyme A bonds to 2 carbon molecule 3. Citric Acid formed: 2 carbon bonded to 4

carbon. Coenzyme goes back to step 2. 4. Citric Acid brokendown: into 5 carbon sugar

carbon dioxide and NADH 5. 5 carbon sugar broken down: Into 4 carbon

sugar, NADH, ATP and Carbon dioxide. 6. 4 carbon rearranged by enzymes. Molecules

of NADH, FADH(electron carrier).

Second Step: Citric Acid Cycle (Krebs Cycle)

Where Mitochondrial matrix Energy Yield 2 ATP and more e-

Acetyl-CoA (2-C) combines with 4-C to form 6-C CITRIC ACID

Citric Acid (6-C) changed to 5-C then to a 4-C Gives off a CO2 molecule NAD+ and FAD pick up the released e-

FAD becomes FADH2 NAD+ becomes NADH + H+

Cycle ALWAYS reforming a 4-C molecule

Krebs Cycle Reactants and Products

Reactants 2 Acetyl CoA

Remember when you form a bond energy is released!! This is the key!!

Products 2 ATP 6 NADH (go to ETC) 2 FADH2 (go to ETC)

4 CO2 (given off as waste)

Products of Kreb Cycle

High energy carriers – NADH and FADH – This is the main goal!!!

Carbon Dioxide 2 ATP molecules 4 carbon molecules to start again HYDROGEN IONS ARE SENT DOWN THE

ELECTRON TRANSPORT CHAIN to make ATP.

Electron Transport

ATP synthesis

Electron Transport Chain

Where inner membrane of mitochondria called cristea.

Energy Yield Total of 32 ATP O2 combines with TWO H+ to form H2O

Exhale - CO2, H2O comes from cellular respiration

Electron Transport - Step 3

1. Proteins inside the membrane of the mito. Remove electrons from NADPh and FADH.

2. Electrons(hydrogen) are transported down the chain of the membrane to be pumped across.

3. ATP synthase(enzyme) puts a P on ADP to make ATP(END GOAL!!).

4. Oxygen enters the cycle to pick up electrons and hydrogen ions to make water that leaves the cycle.

Electron Transport Chain

Electron carriers loaded with electrons and protons from the Kreb’s cycle move to this chain-like a series of steps (staircase).

As electrons drop down stairs, energy released to form a total of 32 ATP – Final Goal!!

Oxygen waits at bottom of staircase, picks up electrons and protons and in doing so becomes water

Electron Transport Chain

Occurs in the cristae of the mitochondria

 Electron Transport ChainSection 9-2

Electron TransportHydrogen Ion Movement

ATP Production

ATP synthase

Channel

Inner Membrane

Matrix

Intermembrane Space

Mitochondrion

Aerobic vs. Anaerobic

Anaerobic DOES NOT require oxygen-

Lactic acid & alcohol fermentation

– Simple– fast – produces smaller

amounts of energy (ATP)

Aerobic requires oxygen – cellular respiration– Yields large

amounts of energy– What is this energy

molecule?ATP, ATP, ATP

Fermentation Without oxygenWithout oxygen:: Pyruvate is converted

into Lactic AcidLactic Acid or AlcoholAlcohol during Fermentation.

Lactic Acid- Muscle cells Alcohol- Yeast, bacteria

40

Anaerobic Cellular Respiration

Some organisms thrive in environments with little or no oxygen

– Marshes, bogs, gut of animals, sewage treatment ponds

No oxygen used= ‘an’aerobic Results in no more ATP, final steps in these pathways

serve ONLY to regenerate NAD+ so it can return to pick up more electrons and hydrogens in glycolysis.

End products such as ethanol and CO2 (single cell fungi (yeast) in beer/bread) or lactic acid (muscle cells)

In the presence of oxygen:

1 Glucose is converted into 36 ATP.

Without oxygen: Only do glycolysis over and over!!!

1 Glucose is converted into 2 ATP.

41

C6H12O6 + 6 O2 => 6 CO2 + 6 H2O + 36 ATP

Two Types of Fermentation

Alcoholic Fermentation Pyruvate converted to

ethyl alcohol and CO2

Carried out by yeast and some bacteria

Used in producing alcohol (both consumable and for ethanol), and for baking

Lactic Acid Fermentation Pyruvate converted to

lactic acid Carried out by muscles

when working hard (muscles need ATP but can’t get O2 )

Causes muscle soreness and cramps

Alcohol Fermentation

Pyruvate

Alcoholic Fermentation

C6H12O6 2 C2H5OH + 2 CO2

(Ethyl Alcohol or Ethanol)

As a result of Alcoholic Fermentation,

Glucose is converted into 2 molecules of Ethyl Alcohol and 2

Molecules of Carbon Dioxide.

Importance of Fermentation

Alcohol Industry - almost every society has a fermented beverage.

Baking Industry - many breads use yeast to provide bubbles to raise the dough.

Alcoholic Fermentation

Bacteria and fungi (yeast)

Ethyl alcohol and carbon dioxide are the end products

Process used to form beer, wine, and other alcoholic beverages

Also used to raise dough, bread

Lactic Acid Fermentation

Uses only Glycolysis.Does NOT require O2

Produces ATP when O2 is not available.

Lactic Acid Fermentation

Carried out by human muscle cells under oxygen debt.

Lactic Acid is a toxin and causes fatigue, soreness and stiffness in muscles.

Lactic Acid Formation

pyruvate + NADH----- lactic acid + NAD+

Fermentation - Summary

Releases 2 ATP from the breakdown of a glucose molecule

Provides ATP to a cell even when O2 is absent.

Energy Tally

36 ATP for aerobic vs. 2 ATP for anaerobic

– Glycolysis 2 ATP

– Kreb’s 2 ATP

– Electron Transport 32 ATP 36 ATP

Anaerobic organisms can’t be too energetic but are important for global recycling of carbon