chapter 9 - cellular respiration. cellular respiration process that releases energy by breaking down...
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CHAPTER 9 - CELLULAR CHAPTER 9 - CELLULAR RESPIRATIONRESPIRATION
CELLULAR RESPIRATIONCELLULAR RESPIRATION
Process that releases energy by Process that releases energy by breaking down food molecules in the breaking down food molecules in the presence of oxygenpresence of oxygen
6 O6 O22 + C + C66HH1212OO66 --> 6 CO --> 6 CO22 + 6 H + 6 H220+ATP 0+ATP
oxygen + glucose --> carbon dioxide oxygen + glucose --> carbon dioxide + water + energy+ water + energy
3 Stages of Cellular Respiration3 Stages of Cellular Respiration1.1. GlycolysisGlycolysis2.2. Krebs CycleKrebs Cycle3.3. Electron Transport ChainElectron Transport Chain
Each stage captures some of the Each stage captures some of the chemical energy available in food chemical energy available in food molecules and uses it to produce molecules and uses it to produce ATPATP
Energy Molecules of Cellular Energy Molecules of Cellular RespirationRespiration
In cellular respiration, several In cellular respiration, several molecules are used as energy molecules are used as energy carriers. These molecules carry carriers. These molecules carry energy from one step of cellular energy from one step of cellular
ADP + P = ATPADP + P = ATP
NAD + H = NADHNAD + H = NADH
FADFAD++ + H + H2 2 = FADH= FADH22
GLYCOLYSISGLYCOLYSISGlycolysis Glycolysis – First step in – First step in releasing the energy of glucose.releasing the energy of glucose.
A molecule of glucose is broken A molecule of glucose is broken into two molecules of pyruvic into two molecules of pyruvic acid (a 3-carbon compound).acid (a 3-carbon compound).– takes place in the cytoplasmtakes place in the cytoplasm– does not require oxygen - does not require oxygen -
anaerobicanaerobic
GLYCOLYSISGLYCOLYSIS
RequiresRequires: 1 Glucose molecule : 1 Glucose molecule (C(C66HH1212OO66), 2 ATP), 2 ATP
ProducesProduces: 2 ATP, 2 NADH and 2 : 2 ATP, 2 NADH and 2 pyruvic acidpyruvic acid
Second Stage: Fermentation or Second Stage: Fermentation or Krebs CycleKrebs Cycle
Glycolysis can be followed by Glycolysis can be followed by fermentation or the Krebs cycle fermentation or the Krebs cycle depending if oxygen is present. depending if oxygen is present. – FermentationFermentation will occur if no oxygen is will occur if no oxygen is
present.present.– Krebs CycleKrebs Cycle will occur if oxygen is will occur if oxygen is
present.present.
GlycolysisGlycolysis
Fermentation Krebs Fermentation Krebs Cycle Cycle
Anaerobic (no oxygen)
Aerobic (oxygen)
Without Oxygen - FermentationWithout Oxygen - Fermentation
AnaerobicAnaerobic - without the presence of - without the presence of oxygenoxygen
FermentationFermentation - releases energy from - releases energy from food molecules in the absence of food molecules in the absence of oxygenoxygen
two types: Alcoholic and Lactic Acid two types: Alcoholic and Lactic Acid FermentationFermentation
Occurs in the cytoplasmOccurs in the cytoplasm
Types of FermentationTypes of Fermentation
AlcoholicAlcoholic - causes bread to rise, used - causes bread to rise, used to make beer and wineto make beer and wine
Lactic Acid Lactic Acid - produced in muscles - produced in muscles during rapid exercise when body during rapid exercise when body can’t supply enough Ocan’t supply enough O22
– causes painful, burning sensation and causes painful, burning sensation and muscle sorenessmuscle soreness
With Oxygen - Kreb’s CycleWith Oxygen - Kreb’s CycleAerobicAerobic - in the presence of oxygen - in the presence of oxygen
Kreb’s Cycle also called Citric Acid Kreb’s Cycle also called Citric Acid CycleCycle
Kreb’s Cycle Kreb’s Cycle - 2nd stage of cellular - 2nd stage of cellular respiration, in which pyruvic acid is respiration, in which pyruvic acid is broken down into CObroken down into CO22 in a series of in a series of energy-extracting reactions, energy-extracting reactions, creating energy molecules.creating energy molecules.– Occurs in the mitochondriaOccurs in the mitochondria
Kreb’s CycleKreb’s Cycle
RequiresRequires: 1 Pyruvic Acid: 1 Pyruvic Acid
ProducesProduces: CO: CO22, NADH, FADH, NADH, FADH22, ATP, ATP
Kreb’s CycleKreb’s Cycle
As a pyruvic acid molecule enters the As a pyruvic acid molecule enters the mitochondria, a carbon is removed, mitochondria, a carbon is removed, forming COforming CO22..
Carbons continue to be rearranged, Carbons continue to be rearranged, releasing more COreleasing more CO22, while allowing the , while allowing the energy carriers to be charged.energy carriers to be charged.
This cycle will happen twice for every This cycle will happen twice for every molecule of glucose broken down in molecule of glucose broken down in glycolysis.glycolysis.
Third Stage: Electron Transport Third Stage: 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 into ATP. cycle to convert ADP into ATP. – Occurs in the mitochondrial matrix.Occurs in the mitochondrial matrix.
Electron Transport ChainElectron Transport Chain (ETC) (ETC)
RequiresRequires: NADH, FADH: NADH, FADH22, ADP, ADP
ProducesProduces: H: H22O, NAD, FAD, ATPO, NAD, FAD, ATP
Electron Transport ChainElectron Transport Chain1.1. The Krebs Cycle generates high-The Krebs Cycle generates high-
energy electrons that are passed to energy electrons that are passed to NADH and FADHNADH and FADH22..
2.2. The high-energy electrons (H+) The high-energy electrons (H+) from NADH and FADHfrom NADH and FADH22 are used up are used up and passed along the proteins in the and passed along the proteins in the ETC.ETC.
Electron Transport ChainElectron Transport Chain
3.3. Oxygen serves as the final electron Oxygen serves as the final electron acceptor forming a water molecule.acceptor forming a water molecule.
4.4. As H+ ions move through the ETC, ATP As H+ ions move through the ETC, ATP synthase spins adding ADP to P synthase spins adding ADP to P forming ATP.forming ATP.
Cellular Respiration TotalsCellular Respiration Totals
1 molecule of glucose produces:1 molecule of glucose produces:– 2 ATP in glycolysis2 ATP in glycolysis– 34 ATP in Kreb’s Cycle and Electron 34 ATP in Kreb’s Cycle and Electron
Transport ChainTransport Chain– waterwater
– COCO22
Types of EnergyTypes of EnergyQuick Energy Quick Energy - Muscles only contain enough ATP - Muscles only contain enough ATP for a few seconds of intense activity. Then, muscle for a few seconds of intense activity. Then, muscle cells produce their ATP by lactic acid fermentation. cells produce their ATP by lactic acid fermentation.
Long Term Energy Long Term Energy - Cellular Respiration is the only - Cellular Respiration is the only way to generate a continuing supply of ATP way to generate a continuing supply of ATP – energy is released more slowly than fermentation, which energy is released more slowly than fermentation, which
is why athletes have to pace themselvesis why athletes have to pace themselves– 15 to 20 min. of activity from carbohydrate stored in the 15 to 20 min. of activity from carbohydrate stored in the
bodybody– after 20 min., energy comes from break down of fatsafter 20 min., energy comes from break down of fats
Photosynthesis vs. RespirationPhotosynthesis vs. Respiration
Photosynthesis and cellular respiration Photosynthesis and cellular respiration take place in opposite directions! take place in opposite directions!
PhotosynthesisPhotosynthesis: Use light energy to build a sugar.: Use light energy to build a sugar.
carbon dioxide + water + light energycarbon dioxide + water + light energy → → sugars + sugars + oxygenoxygen
RespirationRespiration: Break down sugar to release energy.: Break down sugar to release energy.
oxygen + sugarsoxygen + sugars → → carbon dioxide + water + carbon dioxide + water + energyenergy
Photosynthesis vs. RespirationPhotosynthesis vs. Respiration
PhotosynthesisPhotosynthesis::– Use light energy to Use light energy to
build a sugar.build a sugar.– Process that “deposits” Process that “deposits”
or captures energy.or captures energy.– Removes carbon Removes carbon
dioxide from the dioxide from the atmosphere. atmosphere.
– Releases oxygen into Releases oxygen into the atmosphere. the atmosphere.
Photosynthesis vs. Photosynthesis vs. RespirationRespiration
RespirationRespiration::– Break down sugar to Break down sugar to
release energy. release energy. – Process that Process that
“withdraws” or “withdraws” or releases energy.releases energy.
– Removes oxygen from Removes oxygen from the atmosphere. the atmosphere.
– Releases carbon Releases carbon dioxide into the dioxide into the atmosphere. atmosphere.
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