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 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 & FADH 2 Electrons provide energy to pump H+ across inner mitochondrial membrane NAD+/H carry electrons FAD/H 2 carry electrons H+ provide energy for synthesis of ATP O 2 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 C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O + Energy Organisms extract energy from food over several steps in small “bite sized” pieces C 6 H 12 O 6 + 6O 2 Energy 6CO 2 +6H 2 O ATP

Cellular Respiration Occurs in 3 stages: 1.Glycolysis 2.Kreb’s cycle 3.ETC

1. Glycolysis Takes place in the cytoplasm NAD+

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)

A closer look at glycolysis: energy payoff phase (Layer 3)

A closer look at glycolysis: energy payoff phase (Layer 4)

What’s Happened so far? Glycolysis O 2 Used ? Glucose C now Product: ATP # NAD H # Glycolysis glucose

What’s Happened so far? Glycolysis O 2 Used ? Glucose C now Product: ATP # NADH # GlycolysisNoPyruvate22 pyruvate glucose

Electron carriers

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

NAD + as an electron shuttle

Pyruvate as a key juncture in catabolism

After Glycolysis Pyruvic Acid shipped into mitochondria One carbon is removed as CO 2 Attach Coenzyme-A  Acetyl-Co-A Make one NADH for each pyruvic acid

2. Krebs Cycle Remaining two carbons removed as CO 2 For each Acetyl-Co-A: Make 1 ATP 3 NADH 1 FADH 2

A closer look at the Krebs cycle (Layer 1)

A closer look at the Krebs cycle (Layer 2)

A closer look at the Krebs cycle (Layer 3)

A closer look at the Krebs cycle (Layer 4)

This is what you need to know

What’s Happened so far? Krebs Cycle Original C of glucose are now ATPNADHFADH 2 Glycolysis2 pyruvate22 Acetyl CoA formation 2 CO 2 & 2 acetyl CoA 2 Krebs Cycle Total glucose

What’s Happened so far? Krebs Cycle Original C of glucose are now ATPNADHFADH 2 Glycolysis2 pyruvate22 Acetyl CoA formation 2 CO 2 & 2 acetyl CoA 2 Krebs Cycle4 more CO Total6 CO glucose

3. Electron Transport Chain (ETC) Electrons give up energy as passed along Electrons are passed between several molecules

What is oxygen for? Receives electrons at the end of the ETC With H +, forms water

ATP synthase Works like hydro-electric dam Large concentration gradient of H+ builds up across the mitochondrial membrane

*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

ATP synthase, a molecular mill

1.Enzymes 2.ATP 3.NAD + 4.vitamins 5.proteins 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.

1.transported... becoming more energetic 2.digested... becoming more energetic 3.reduced... losing electrons to it 4.oxidized... losing electrons to it 5.oxidized... gaining electrons from it Energy transfer in living things works through redox reactions, in which one substance is _____ by another substance, thereby _____.

1.glycolysis... the Krebs cycle... yield of electrons transported to the ETC 2.glycolysis... the ETC... yield of electrons transported to the cytosol 3.Redox reactions... fatty acid breakdown... yield of calories 4.The Krebs cycle... the ETC... numerous redox reactions 5.The Krebs cycle... the ETC... fatty-acid breakdown _____ and _____ are important not so much for the ATP produced in them, but for their _____.

At most, how many molecules of ATP can be produced per glucose molecule in cellular respiration?

1.both atmospheric nitrogen and the oxygen for energy transformation 2.oxygen to donate electrons to 3.nitrogen to donate phosphate groups to oxygen 4.oxygen to act as the final acceptor of electrons in the ETC 5.oxygen to donate phosphate groups to ADP, making it ATP We need to breathe because we need

Anaerobic Respiration Fermentation live off glycolysis alone

Alcoholic Fermentation Pyruvate + NADH Ethanol + CO 2 + NAD+ Vinegar

Lactic Acid Fermentation Pyruvate + NADH Lactic Acid + NAD+

Fermentation allows the cycle of glycolysis to continue by regenerating NAD+

Fermentation

An overview of cellular respiration (Layer 1)

An overview of cellular respiration (Layer 2)

Substrate-level phosphorylation

An overview of cellular respiration (Layer 3)

Max of 36 ATP per Glucose

What is all of the ATP used for?