How Cells Harvest Chemical Energy
ObjectivesDefine cellular respirationDescribe the major events in glycolysisCompare and contrast lactic acid fermentation and alcoholic fermentationSummarize the events of the Krebs cycle and the electron transport chainRelate aerobic respiration to the structure of a mitochondrion
Define VocabularyAcetyl CoA Aerobic respiration Alcoholic fermentation Anaerobic Cellular respiration Citric acidFermentationGlycolysisKilocalorie Krebs cycle Mitochondrial matrix Oxaloacetic acidPyruvic acid Lactic acid fermentationNAD+---NADH, FAD+---FADH2Read Pgs. 131-136 for tomorrow!
AgendaGo over Vocabulary DefinitionsNotes: Mitochondrion structure, Glycolysis & FermentationComplete Role of ATP in Cells PSSA WorksheetWhat energy carrying compound is made inside the mitochondria?What occurs during glycolysis?How is lactic acid fermentation different from alcoholic fermentation?
Acetyl CoA -two-carbon moleculeAerobic respiration - process that produces large amounts of ATPAlcoholic fermentation form of anaerobic respiration which involves the conversion of pyruvic acid to ethyl alcohol and carbon dioxideAnaerobic - does not require oxygenCellular respiration - process in which cells make ATP by breaking down organic compoundsCitric acid -six-carbon molecule in the Krebs cycleFermentation - the recycling of NAD+ under anaerobic conditionsGlycolysis - pathway in which two molecules of pyruvic acid are producedKilocalorie - unit of energyKrebs cycle -pathway that breaks down acetyl CoA producing carbon dioxide, hydrogen atoms, and ATPMitochondrial matrix -the space inside the inner membrane of a mitochondriaOxaloacetic acid -four-carbon molecule that combines with Acetyl CoAPyruvic acid - three-carbon product of glycolysisLactic acid fermentation form of anaerobic respiration which involves the conversion of pyruvic acid to lactic acidVocabulary Quiz is scheduled for Wednesday, April 15th!
Enzymes36 ADP + 36 P 36 ATP
All living organisms need Energy!Photoautotrophs get energy from sunlightHeterotrophs get energy from organic compoundsChemoautotrophs get energy from inorganic compounds
The ULTIMATE source of energy for plants and animals is the Sun!
ATPRegenerated through process of Chemiosmosis
The Organelle of Cellular RespirationCellular respiration takes place in both plant and animal cells. The organelle in which it takes place is the mitochondrion. This is also known as the power-house of the cell.
Stages of Cellular RespirationGlycolysisIf oxygen present: Aerobic RespirationIf oxygen not present: Fermentation
C6H12O6 + 6O2 --- 6CO2+ 6H2O + energy
Step #1: GlycolysisBiochemical pathwayGlucose is oxidized into two molecules of pyruvic acidTake place in the cytosol ( cytoplasm) of the cell
Glucose is oxidized (looses electrons) into two molecules of pyruvic acid(pyruvate).
Net gain of 2 ATP, 2 NADH
Glycolysis is inefficient in energy-utilization.Aerobes organisms performing respiration in the presence of oxygen must go through Krebs Cycle and Electron Transport Chain in order to produce more energy after glycolysisAnaerobes organisms respiring in the absence of oxygen can survive and make use of the energy released from glycolysis itselfTwo forms of anaerobes are:Facultative anaerobes these can survive in aerobic and anaerobic conditions. Obligate anaerobes Survive only as anaerobes. http://www.science.smith.edu/departments/Biology/Bio231/glycolysis.html
Anaerobic RespirationTwo forms of anaerobic respiration are:Alcoholic fermentationLactic Acid Fermentation
Yeasts, anaerobic bacteria, etc undergo alcoholic fermentation.In this process, the pyruvic acid from Glycolysis is converted to Ethanol and Carbon dioxide.Commercially, this is used for making wine, bread, beer
Lactic Acid FermentationThis also occurs in human muscle cells during stress / when oxygen is scarce.In this process, the pyruvic acid from Glycolysis is converted to Lactic acid. No Carbon dioxide is produced.Lactic acid produced can be changed back to pyruvic acid when oxygen levels return to normal
ReviewWhat energy carrying compound is made inside the mitochondria?What occurs during glycolysis?How is lactic acid fermentation different from alcoholic fermentation?
Read Pgs. 137-144 in book & complete Role or ATP PSSA Worksheet.
AgendaReview VocabularyNotes: Aerobic RespirationComplete Measuring Respiration PSSA worksheetHow is aerobic respiration different for prokaryotes and eukaryotes?What is the main purpose of the Krebs Cycle?How does the efficiency of aerobic respiration with anaerobic respiration compare?
Aerobic RespirationOxygen must be presentCarried out in:Cytosol(cytoplasm) in prokaryotesMitochondrial matrix in eukaryotesStagesKrebs cycleElectron transport chain
Prior to the Krebs CycleThe 3-C containing pyruvic acid produced at the end of Glycolysis is too bulky to enter the mitochondria from the cytoplasm. Hence, it is groomed (broken down further) with the help of Coenzyme A to form Acetyl Co AThis Acetyl CoA can easily pass into the mitochondrial matrix, where it undergoes Krebs Cycle.
Krebs CycleBiochemical pathway that takes place in the mitochondrial matrixBreaks down acetyl Co A into citric acidProduces carbon dioxide, hydrogen atoms, and ATPMain purpose is to capture H+
NAD and FAD pick up Hydrogen atoms and take them to the Electron Transport Chain
Electron Transport ChainRedox reactions release energy when electrons pass through a cascade of electron carrier molecules. NADH and FADH release protons to make ATP through chemosmosisFinal electron acceptor is oxygen Allows e- to keep moving down transport chain, therefore ATP can be produced.Bonds with H+ and released as water .
Review of Stages for Aerobic Respiration http://www.studystack.com/wordscramble-93931
Net Energetics of Cellular Respiration Per Molecule of GlucoseRemember Anaerobic Respiration produces only 2 ATP!
Stages of Cellular RespirationNet ATP producedNADH producedFADH2 producedCO2 producedGlycolysis2200Grooming of Pyruvic acid0202Krebs Cycle2624E.T.C.34000Net # of molecules381026
ReviewHow is aerobic respiration different for prokaryotes and eukaryotes?What is the main purpose of the Krebs Cycle?How does the efficiency of aerobic respiration with anaerobic respiration compare?
Complete Measuring Respiration PSSA worksheet
AgendaVocabulary QuizPea Respiration LabComplete Chapter Review Pg. 146-147 and hand in on Thursday, April 16thUnderstanding Key Concepts #5-11, 13,14Critical Thinking #17-20Standardized Test Preparation #1-8, Short Response, Extended Response A & B
AgendaVocabulary QuizPea Respiration Lab