adp, atp and cellular respiration vocabualry 2/25 – atp 2/27 – pigment i can…… i can……...
TRANSCRIPT
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
Copyright Cmassengale
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