2 Food=chemical energy Cellular Respiration All living things need energyEnergy in the form of…Food=chemical energyCell energy=ATP
3 How Do We Get Energy From ATP? By breaking the high- energy bonds between the last two phosphates in ATP
4 When is ATP Made in the Body? During a Process called Cellular Respiration that takes place in both Plants & Animals
5 What is cellular respiration ? Cellular respiration is the set of the metabolic reactions and processes that take place in the cells of organisms to convert biochemical energy from nutrients into (ATP),The reactions involved in respiration are catabolic reactions, which break large molecules into smaller ones, releasing energy
6 Cellular RespirationIncludes pathways that require oxygenBreakdown of one glucose molecule produces 38 ATP molecules
12 STEP 1 GlycolysisGlycolysis is takes place in the cytosol of cells in all living organisms.This pathway can function with or without the presence of oxygen.process converts one molecule of glucose into two molecules of pyruvate (pyruvic acid),
13 generating two net molecules of ATP. Four molecules of ATP per glucose are actually produced,however, two are consumed as part of the preparatory phase.The overall reaction can be expressed this way:Glucose + 2 NAD+ + 2 Pi + 2 ADP → 2 pyruvate + 2 NADH + 2 ATP + 2 H+ + 2 H2O + heat
18 Steps 2: The Fate of PYRUVATE 1. As pyruvate enters the mitochondrion, a modifies pyruvate to acetyl CoA which enters the Krebs cycle in the matrix. 2. A carboxyl group is removed as CO2. 3. A pair of electrons is transferred from the to NAD+ to form NADH
20 When oxygen is present, the mitochondria will undergo aerobic respiration which leads to the Krebs cycle.However, if oxygen is not present, fermentation of the pyruvate molecule will occur.In the presence of oxygen, when acetyl-CoA is produced, the molecule then enters the citric acid cycle (Krebs cycle)
21 inside the mitochondrial matrix, and gets oxidized to CO2 while at the same time reducing NAD to NADH.NADH can be used by the electron transport chain to create further ATP as part of oxidative phosphorylation.The citric acid cycle is an 8-step process involving different enzymes and co-enzymes.
22 Steps3: KREBS CYCLE or TCA This is also called the citric acid or the tricarboxylic acid cycleTakes place in matrix of mitochondriaRequires Oxygen (Aerobic)Each cycle produces 1 ATP, 3 NADH, and 1 FADH
23 The TCA or KREBS CYCLE4 CO26NADH2FADH2 more ATP
25 The conversion of pyruvate and the Krebs cycle produces large quantities of electron carriers.•So what do you think the major purpose of theKrebs cycle is??
26 Electron TransportThe mitochondria has two membranes the outer one and the inner membraneThe H+ which are brought to mitochondria accumulate between these two membranes.
27 the electrons move from molecule to molecule until they combine with oxygen and hydrogen ions to form water.As they are passed along the chain, the energy carried by these electrons is stored in the mitochondrion in a form that can be used to synthesize ATP
28 Electrons carried by NADH are transferred to the first molecule in the electron transport chain. The electrons continue along the chain that includes several cytochrome proteins and one lipid carrier.The electrons carried by FADH2 added to a later point in the chain.Electrons from NADH or FADH2 ultimately pass to oxygen.The electron transport chain generates no ATPdirectly.
31 ONE GLUCOSE MOLECULE PRODUCES 38 ATP Each NADH ATPEach FADH ATPGlycolysis (2 NADH) 6 ATPPrep for Citric Acid 6 ATPCitric Acid (6 NADH) ATP(2 FADH2) 4 ATP34 ATPdirect 4 ATPtotal ATP
32 What happens when there is no Oxygen to accept the electrons? If no oxygen is available, cells can obtain energy through the process of anaerobic respiration.A common anaerobic process is fermentation.Fermentation is not an efficient process and results in the formation of far fewer ATP molecules than aerobic respiration.There are two primary fermentation processes:Lactic Acid FermentationAlcohol Fermentation
33 Fermentation allows the production of a small amount of ATP without oxygen.
34 Lactic acid fermentation occurs when oxygen is not available.For example,in muscle tissues during rapid and hard exercise, muscle cells may be depleted of oxygen. They then switch from respiration to fermentation.
35 The pyruvic acid formed during glycolysis is broken down to lactic acid and energy is released (which is used to form ATP).Glucose → Pyruvic acid → Lactic acid + energy
36 Lactic acid that builds up in the tissue causes a burning, painful sensation. results in muscle soreness
38 Alcohol fermentationoccurs in yeasts and some bacteria.
39 Alcohol FermentationPyruvate is converted to ethanol (ethyl alcohol) in 2 steps.1. carbon dioxide is released from pyruvate, which is converted to acetaldehyde.2. acetaldehyde is reduced by NADH to ethanol.Regenerating a supply of NAD+
41 Anaerobic Respiration Aerobic Respiration Definition Anaerobic respiration is respiration without oxygen; the process uses a respiratory electron transport chain but does not use oxygen as the electron acceptorsAerobic respiration uses oxygenDefinitionProduces lactic acid (in lactic acid fermentation but not in alcoholic fermentation)Does not produce lactic acidProduction of lactic acid:Low (2 ATP molecules)High (36-38 ATP molecules)Amount of energy released:Lactic Acid Fermentation - lactic acid, ATP Alcoholic Fermentation - ethyl alcohol, ATP, carbon dioxideCarbon dioxide, water, ATPProducts:glucoseglucose, oxygenReactants
42 Anaerobic Aerobic Site of reactions: Stages: CytoplasmCytoplasm and mitochondriaSite of reactions:Glycolysis, fermentationGlycolysis, Krebs cycle, Electron Transport ChainStages:
43 The aerobic system requires 60 to 80 seconds to produce energy for resynthesizing ATP from ADP + P. The heart rate and respiratory rate must increase sufficiently to transport the required amount of O2 to the muscle cells, allowing glycogen to break down in the presence of oxygen.
44 The lactic acid system need 8 to 10 seconds to produce energy
46 Summary QuizWhat are the reactants of aerobic respiration?? Products? Equation?List the three respiratory stages:Where in the cell do each occur?What are the products of each?How much ATP is produced byAnaerobic gylcolysis?Aerobic glycolysis?List the 2 types of fermentation??