Cells Memory JoggerCells Memory Jogger

1.1. What is the process called when a What is the process called when a phosphate is added?phosphate is added?

2.2. ATP stands for ___________ ___________.ATP stands for ___________ ___________.

3.3. What does ‘lysis’ generally mean at the What does ‘lysis’ generally mean at the end of a word?end of a word?

4.4. Which organelle is the ‘powerhouse of a Which organelle is the ‘powerhouse of a cell’?cell’?

5.5. What does ‘aerobic’ mean?What does ‘aerobic’ mean?

Cells Memory JoggerCells Memory Jogger1.1. What is the process called when a phosphate is What is the process called when a phosphate is

added?added?

2.2. ATP stands for ___________ ___________.ATP stands for ___________ ___________.

3.3. What does ‘lysis’ generally mean at the end of a word?What does ‘lysis’ generally mean at the end of a word?

4.4. Which organelle is the ‘powerhouse of a cell’?Which organelle is the ‘powerhouse of a cell’?

5.5. What does ‘aerobic’ mean?What does ‘aerobic’ mean?

phosphorylation

Adenosine triphosphate

to split or break apart

mitochondria

requires oxygen

RespirationRespiration

The Chemistry The Chemistry of Respirationof Respiration

energy and mitochondria clip

The role of ATP reviewThe role of ATP review

►ATP ATP storesstores the energy in the the energy in the thirdthird bond bond of the moleculeof the molecule

►The energy is The energy is releasedreleased when that bond when that bond is broken to release the third inorganic is broken to release the third inorganic phosphate.phosphate.

► Pi= the phosphoric acid

P

adenosine P P

+

Energy released to do work

ATP

ADP

Enzymes

adenosine P P P

SummarySummary

ATP

ADP + Pi

energy (out)

energy (in)

cellular respiration

cell activities

ATP

energy (out)

cellular respiration

cell activities

The whole process is an enzyme controlled reaction.

►The process by which food molecules (ex: glucose) The process by which food molecules (ex: glucose) are broken down to produce ATP.are broken down to produce ATP.

►Takes place in the mitochondria of plants and Takes place in the mitochondria of plants and animals.animals.

►There are 3 stages of respiration:There are 3 stages of respiration:1. Glycolysis1. Glycolysis

2. Krebs Cycle2. Krebs Cycle

3. Electron Transport Chain3. Electron Transport Chain

►Chemical Equation:Chemical Equation:

CC66HH1212OO66 + 6O + 6O22 6CO6CO22 + 6H + 6H22O + EnergyO + Energy

Cell RespirationCell Respiration

breathing and respiration intro. click 16-22 (aerobic resp.)

Aerobic respirationAerobic respiration = respiration with = respiration with oxygenoxygen

Aerobic respiration happens in Aerobic respiration happens in 33 stages:stages:

Stage 1Stage 1 – – GlycolysisGlycolysis

glycoglyco lysislysis

glucose splittingglucose splitting

2 ATP needed 2 ATP needed to start to start reaction, 4 reaction, 4 ATP are ATP are produced thus produced thus the net gain is the net gain is 2 ATP from 2 ATP from glycolysis.glycolysis.

In glycolysis, a glucose molecule is broken down into two molecules of pyruvic acid.

energy released to make small quantity of ATP(2 molecules)

series of enzyme controlled reactions

pyruvic acid

glucose

Glycolysis does not require oxygen

In both eukaryotes and prokaryotes, this process occurs in the cytosol of the cell.

The cytosol is the portion of the cytoplasm not contained within membrane-bound organelles. Cytosol makes up about 70% of the cell volume and is composed of water, salts and organic molecules.

Breakdown of Pyruvic acidBreakdown of Pyruvic acid

The pyruvic acid made in glycolysis The pyruvic acid made in glycolysis (stage1)(stage1) still contains a lot of still contains a lot of energyenergy

It can only be broken down to It can only be broken down to release the rest of the energy release the rest of the energy in the in the presencepresence ofof oxygenoxygen..

Stage 2: Stage 2: Krebs CycleKrebs Cycle►Pyruvic acid molecules then move into Pyruvic acid molecules then move into

the mitochondria to begin the next stage the mitochondria to begin the next stage of cellular respiration: the Krebs Cycle.of cellular respiration: the Krebs Cycle.

►During the Krebs Cycle, pyruvic acid During the Krebs Cycle, pyruvic acid is broken down into carbon dioxide in is broken down into carbon dioxide in a series of energy-extracting a series of energy-extracting reactions.reactions.

►Citric Acid is created in this cycle Citric Acid is created in this cycle thus giving it the nickname Citric thus giving it the nickname Citric Acid cycle.Acid cycle.

►Net ATP Production is 2 ATP from the Net ATP Production is 2 ATP from the Krebs Cycle.Krebs Cycle.

Mitochondrial structureMitochondrial structure

Krebs cycle takes place in the matrix.

Stage 2: Krebs CycleStage 2: Krebs Cycle

►The enzyme involved in this stage is The enzyme involved in this stage is referred to as acetyl-CoAreferred to as acetyl-CoA

►The citric acid is broken down into a 5-The citric acid is broken down into a 5-carbon compound, then into a 4-carbon carbon compound, then into a 4-carbon compound. Energy is being released along compound. Energy is being released along the way.the way.

►Electron carriers in the form of NADH and Electron carriers in the form of NADH and FADH2 are produced, which transport FADH2 are produced, which transport energized electrons along the electron energized electrons along the electron transport chain in the mitochondria.transport chain in the mitochondria.

Stage 3: Electron Transport Stage 3: Electron Transport ChainChain

►The electron transport chain uses the The electron transport chain uses the high-energy electrons from the Krebs high-energy electrons from the Krebs Cycle to convert ADP to ATP.Cycle to convert ADP to ATP.

►Same idea as in photosynthesis: Same idea as in photosynthesis: energized electrons from Citric Acid energized electrons from Citric Acid Cycle are passed from protein to Cycle are passed from protein to protein, losing energy as they go.protein, losing energy as they go.

►The energy is used to make ATP.The energy is used to make ATP.

Stage 3: Electron Transport Stage 3: Electron Transport ChainChain

►Takes place in the mitochondria in the Takes place in the mitochondria in the cristae or inner membrane.cristae or inner membrane.

►Requires oxygen to assist in passing Requires oxygen to assist in passing the electrons from protein to protein.the electrons from protein to protein.

►Water is formed.Water is formed.►Net ATP Gain: 32 ATP from the Net ATP Gain: 32 ATP from the

electron transport chain.electron transport chain.

So why do we need oxygen?So why do we need oxygen?

►Oxygen serves as the final Oxygen serves as the final electron acceptor of the electron electron acceptor of the electron transport chain. Therefore, oxygen transport chain. Therefore, oxygen is essential for getting rid of low-is essential for getting rid of low-energy electrons and hydrogen energy electrons and hydrogen ions, the wastes of cellular ions, the wastes of cellular respiration.respiration.

Cell Respiration SummaryCell Respiration Summary

►Total process (Glycolysis, Citric Acid Total process (Glycolysis, Citric Acid Cycle, and Electron Transport Chain) Cycle, and Electron Transport Chain) produces 36 ATPs.produces 36 ATPs.

►All of this is from 1 molecule of glucose!All of this is from 1 molecule of glucose!►This happens in 1 mitochondrion (liver This happens in 1 mitochondrion (liver

cells may have 2500 mitochondria cells may have 2500 mitochondria each!)each!)

►Cells and organisms require a HUGE Cells and organisms require a HUGE amount of energy!!amount of energy!!

Anaerobic Anaerobic RespirationRespiration(in animals)(in animals)

anaerobic = in the anaerobic = in the absence of oxygenabsence of oxygen

In In lowlow oxygen conditions or oxygen conditions or during during heavy exerciseheavy exercise, when , when

not enough oxygen can be not enough oxygen can be supplied, muscle cells swap to supplied, muscle cells swap to

anaerobicanaerobic respirationrespiration

Lactic Acid FermentationLactic Acid Fermentation

►Glycolysis still takes place but is Glycolysis still takes place but is followed by this type of fermentation. followed by this type of fermentation.

►FermentationFermentation: releases energy from : releases energy from food molecules in the absence of food molecules in the absence of oxygenoxygen

glycolysis still happens as it does not require oxygen

in absence of oxygen pyruvic acid is turned into lactic acid.

pyruvic acid

lactic acid

glucose

2 ADP + 2 Pi

2 ATP

A build up of lactic acid produces A build up of lactic acid produces musclemuscle fatiguefatigue. .

Muscle fatigue makes muscles ache Muscle fatigue makes muscles ache and contract less powerfully.and contract less powerfully.

A recovery period is needed. During A recovery period is needed. During this time more this time more oxygenoxygen is taken in to is taken in to convert the lactic acid back into convert the lactic acid back into pyruvic acid again.pyruvic acid again.2 ATP’s are produced.2 ATP’s are produced.

SummarySummary

oxygen debte.g. during hard exercise

oxygen debtrepaid during recovery time

glucose

pyruvic acid

lactic acid

Anaerobic Anaerobic Respiration Respiration

in plantsin plants

The same process The same process occurs in plants and occurs in plants and yeast in low oxygen yeast in low oxygen

conditions, e.g. muddy, conditions, e.g. muddy, flooded soils.flooded soils.

Alcoholic FermentationAlcoholic Fermentation►Used most commonly by yeast.Used most commonly by yeast.►COCO22 + ethyl alcohol are produced from 2 + ethyl alcohol are produced from 2

pyruvic acids.pyruvic acids.►2 ATPs are produced2 ATPs are produced

►These processes (fermentation) are not These processes (fermentation) are not ideal, because they are not as efficient at ideal, because they are not as efficient at producing energy, and so they occur in producing energy, and so they occur in lower organisms, or under distress.lower organisms, or under distress.

glycolysis still happens, producing 2 ATP molecules

This time in absence of oxygen, pyruvic acid is turned into carbon dioxide and ethanol

glucose

pyruvic acid

ethanol + carbon dioxide

This is irreversible

2 ADP + 2 Pi

2 ATP

Energy & ExerciseEnergy & Exercise

►Quick energyQuick energy – Lactic Acid – Lactic Acid fermentation is used to get quick fermentation is used to get quick energy and gives off lactic acid as a by energy and gives off lactic acid as a by product, thus the muscle pain.product, thus the muscle pain.

►Long-Term EnergyLong-Term Energy – Use cellular – Use cellular respiration to produce energy. respiration to produce energy. Exercising or activities that last for at Exercising or activities that last for at least 15 to 20 minutes. Best form for least 15 to 20 minutes. Best form for weight control.weight control.

Comparison of aerobic and Comparison of aerobic and anaerobic respirationanaerobic respiration

Aerobic Aerobic respirationrespiration

Anaerobic RespirationAnaerobic Respiration

in animalsin animals in plants and yeastin plants and yeast

Oxygen required?Oxygen required? yesyes nono nonoGlycolysis occursGlycolysis occurs yesyes yesyes yesyesATP yieldATP yield 36ATP36ATP 2ATP2ATP 2ATP2ATPGlucose completely broken Glucose completely broken

down?down? yesyes nono nonoEnd productsEnd products Carbon Carbon

dioxide dioxide and and waterwater

Lactic Lactic acidacid

Ethanol Ethanol and carbon and carbon dioxidedioxide

Comparing Photosynthesis & Comparing Photosynthesis & RespirationRespiration

PhotosynthesisPhotosynthesis Cellular Cellular RespirationRespiration

FunctionFunction Energy StorageEnergy Storage Energy Energy ReleaseRelease

LocationLocation ChloroplastsChloroplasts MitochondriaMitochondria

Reactants Reactants COCO22 and H and H22OO CC66HH1212OO66 and and OO22

ProductsProducts CC66HH1212OO66 and O and O22 COCO22 and H and H22OO

EquationEquation 6CO6CO22 + 6H + 6H22O O CC66HH1212OO66 + 6O + 6O22

CC66HH1212OO66 + 6O + 6O22

6CO6CO22 + 6H + 6H22OO

Cool WebsitesCool Websites

► SongYouTube - cellular respiration on SongYouTube - cellular respiration on Cellular RespirationCellular Respiration

► http://www.youtube.com/watch?http://www.youtube.com/watch?v=fmyby8zWeSU&mode=related&search=v=fmyby8zWeSU&mode=related&search=

► http://www.phschool.com/science/http://www.phschool.com/science/biology_place/labbench/lab5/cellular.htmlbiology_place/labbench/lab5/cellular.html

►Movie on Cellular RespirationMovie on Cellular Respiration

http://www.youtube.com/watch?v=kPNVRDAx7Jc