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Cellular Respiration. KEY WORDS: Oxidation Reduction NAD/ NADH FAD/ FADH 2 Cellular respiration Glycolysis Kreb’s cycle Electron transport chain ATP synthase. Food is used to energize ATP. Electrons transfer energy to Energize ATP. REDOX REACTIONS Oxidation = Losing electrons
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Cellular Respiration KEY WORDS:Oxidation Reduction NAD/ NADH FAD/ FADH2 Cellular respiration Glycolysis Kreb’s cycle Electron transport chain ATP synthase
Electrons transfer energy toEnergize ATP REDOX REACTIONS Oxidation = Losing electrons Reduction = Gaining electrons TIP: OIL RIG Gradual transfer of electrons provides most energy (ATP) from food
Main Players: Making ATP Food used to make ATP and NADH & FADH2 Electrons provide energy to pump H+ across inner mitochondrial membrane NAD+/H carry electrons FAD/H2carry electrons H+ provide energy for synthesis of ATP O2 final electron acceptor in ETC Cytosol location of glycolysis Mitochondria location of Kreb’s cycle & ETC ATP Synthase brings together ADP and P to make ATP
Obtaining Energy from Food C6H12O6 + 6O2 6CO2 + 6H2O + Energy 6CO2+6H2O ATP Energy Energy Energy • Organisms extract energy from food over several steps in small “bite sized” pieces C6H12O6+ 6O2
CellularRespiration • Occurs in 3 stages: • Glycolysis • Kreb’s cycle • ETC
1. Glycolysis NAD+ • Takes place in the cytoplasm
A closer look at glycolysis: energy investment phase (Layer 1) Good News! You don’t need to know the steps of glycolysis! You need to know what goes in and what comes out But here are the steps, FYI…
A closer look at glycolysis: energy investment phase (Layer 2)
What’s Happened so far?Glycolysis glucose pyruvate pyruvate
Some energy captured as electrons • Energy in food in form of high energy electrons • Electrons captured when food is broken down • Held by electron carriers • NADH, FADH
After Glycolysis • Pyruvic Acid shipped into mitochondria • One carbon is removed as CO2 • Attach Coenzyme-A Acetyl-Co-A • Make one NADH for each pyruvic acid
2. Krebs Cycle • Remaining two carbons removed as CO2 • For each Acetyl-Co-A: • Make • 1 ATP • 3 NADH • 1 FADH2
3. Electron Transport Chain (ETC) • Electrons are passed between several molecules • Electrons give up energy as passed along
What is oxygen for? With H+, forms water Receives electrons at the end of the ETC
ATP synthase • Large concentration gradient of H+ builds up across the mitochondrial membrane • Works like hydro-electric dam
*H+ is pumped against its gradient into the mitochondrial matrix. *Energy for active transport comes from electrons
Harnessing energy in small steps allows the cell to get more energy that can be used to do work
Free energy of electrons decreases as they are passed through the ETC
Chemiosmosis couples the electron transport chain to ATP synthesis
You need energy to think, to keep your heart beating, to play a sport, and to study this book. This energy is directly supplied by _____, which is (are) produced in the process of cellular respiration. Enzymes ATP NAD+ vitamins proteins
Energy transfer in living things works through redox reactions, in which one substance is _____ by another substance, thereby _____. transported ... becoming more energetic digested ... becoming more energetic reduced ... losing electrons to it oxidized ... losing electrons to it oxidized ... gaining electrons from it
_____ and _____ are important not so much for the ATP produced in them, but for their _____. glycolysis ... the Krebs cycle ... yield of electrons transported to the ETC glycolysis ... the ETC ... yield of electrons transported to the cytosol Redox reactions ... fatty acid breakdown ... yield of calories The Krebs cycle ... the ETC ... numerous redox reactions The Krebs cycle ... the ETC ... fatty-acid breakdown
At most, how many molecules of ATP can be produced per glucose molecule in cellular respiration? 2 8 24 36 75
We need to breathe because we need both atmospheric nitrogen and the oxygen for energy transformation oxygen to donate electrons to nitrogen to donate phosphate groups to oxygen oxygen to act as the final acceptor of electrons in the ETC oxygen to donate phosphate groups to ADP, making it ATP
Anaerobic Respiration Fermentation • live off glycolysis alone
Alcoholic Fermentation Ethanol + CO2 + NAD+ Vinegar Pyruvate + NADH
Lactic Acid Fermentation Lactic Acid + NAD+ Pyruvate + NADH
Fermentation allows the cycle of glycolysis to continue by regenerating NAD+