Presentation on theme: "Cellular Respiration Glycolysis Krebs cycle Electron transport."— Presentation transcript:
Cellular Respiration Glycolysis Krebs cycle Electron transport
Learning check This figure represents an overview of the different processes of cellular respiration. a) 1. Glycolysis; 2. Electron transport chain; 3. Krebs cycle b) 1. Glycolysis; 2. Krebs cycle; 3. Electron transport chain c) 1. Krebs cycle; 2. Electron transport chain; 3. Glycolysis d) 1. Electron transport chain; 2. Glycolysis; 3. Krebs cycle Which of the following correctly identifies the different processes?
What would happen to the flow of electrons if oxygen were not present? a.The flow of electrons would continue but at a slower rate. b.The flow would cease and ATP production would stop. c.The presence of oxygen would have no effect.
Cyanide binds strongly with the last electron carrier in the chain. How would this affect the flow of electrons? a.The flow of electrons would continue but at a slower rate. b.The flow would cease and ATP production would stop. c.The presence of cyanide would have no effect.
How many ATPs?
Cell Respiration Overview Glucose:Stores energy in the molecule Cell respiration: Breaks down the molecules Extracts the contained energy 1 st stage: Cytoplasm 2 nd & 3 rd stage: Transfers electrons (from glucose) To hydrogen carriers (e.g., NADH) And to make ATP Mitochondria Giving off waste products (CO 2 & H 2 O)
1 st stage: Glycolysis 2 nd stage: Krebs cycle (or citric acid) 3 rd stage: Electron transport
Glycolysis, in the cytoplasm Series of steps (but 2 phases) Glucose2 pyruvic acid molecules As bonds in glucose are broken Electrons (and H + ions)NAD + NADH GlucoseIs oxidized NAD + Is reduced Net output is 2 ATP for each glucose molecule But, most of the released energy carried by NADH 1. 2.
Glycolysis, phase 1 Some ATP is used to start the ‘breakdown’ of glucose Cytoplasm Mitochondria View Activity: Glycolysis
Glycolysis, phase 2 High energy electrons are donated To NAD+Forming NADH
Glycolysis, phase 2 And, phosphate groups are transferred ATP is made
In-between glycolysis & Krebs Pyruvic acid molecules are modified Just before (or as) they enter the mitochondria And CO 2 is released The altered molecule is acetic acid(…vinegar!) Acetic acid is attached to a carrier molecule Called coenzyme A And forms acetyl CoA To the mitochondrion
Learning check Name molecule 2.Name molecule 3.Name molecule 4.Name the reaction 5.Name of molecule 6.What does the arrow refer to? 7.Name of molecule 8.Name of molecule 9.Where does this take place? 6
Krebs cycle, in the mitochondria Net output is 2 ATP for each glucose molecule But again, most of the released energy carried by NADH Series of reactions And more CO 2 is released Continues to break down the sugar Captures more energy As NADH & FADH 2 Present as acetic acid
Krebs (citric acid) cycle & energy production Fuel:Acetic acid Citric acid Acceptor molecule Waste:2 CO View Activity: The Citric Acid Cycle
Electron Transport, in the mitochondria Most of the ATP is produced in the ET And, NADH & FADH donate their electrons to the ET Which produces ~ 34 ATP O 2 exerts a strong pull on electrons At the end of the chain of steps And combines electrons & H + ions to form H 2 O The ‘downhill’ flow of electrons powers an enzyme ATP synthase
Electron Transport An array of molecules(…proteins) In the inner membrane of the mitochondrion View Activity: Electron Transport
Electrons move from one member to the next The energy given up pumps H+ to inner space Matrix Oxygen captures electrons Hydrogens are added, water forms
Matrix The buildup of H + ions give up energy When they diffuse through a special protein ATP synthase ATP synthase captures their energy To make ATP
Learning check, name the numbered parts How many?
Learning check 1. Of the 3 stages of cell respiration, which produces the most ATP per glucose? 2. In glycolysis, _______ is oxidized and _______ is reduced. 3. The final electron acceptor of the electron transport chains in mitochondria is _______.
Learning check 4. Cells can harvest the most chemical energy from which of the following? a.An NADH molecule b.A glucose molecule c.Six carbon dioxide molecules d.Two pyruvic acid molecules