Cellular Respiration AP Biology

The Equation C 6 H 12 O 6 + 6O 2  6CO 2 + 6H ATP C 6 H 12 O 6 = glucose 6O 2 = oxygen gas 6CO 2 = carbon dioxide 6H 2 0 = water ATP = energy

Redox Reaction C 6 H 12 O 6 Loses electrons Oxidized to CO 2 O 2 Gains electrons Reduced to H 2 O

What happens….. High energy electrons (e-) Stripped from C 6 H 12 O 6 Used to do work - create H+ concentration gradient Finally accepted by oxygen (O 2 )

Mitochondria Site of cellular respiration Structure

Mitochondria Relating structure to function Intermembrane space Allows for the accumulation of H+ Membranes not permeable to H+

Mitochondria Relating structure to function Inner membrane Cristae Large surface area for ETC

Mitochondria Relating structure to function Matrix Segregates chemicals of Krebs cycle

NADH Production Enzymes dehydrogenases Remove 2 hydrogens (2 H+ and 2 e-) from substrate Add 2 electrons and 1 H+ to NAD+ 2 e- + 1 H+ + NAD+  NADH NAD+ reduced

Glycolysis

Energy investment Uses 2 ATP molecules Splits glucose

Glycolysis Energy yielding 4 ATP molecules produced by substrate level phosphorylation 2 pyruvate (3-C) produced Electrons transferred to NAD+ 2 NADH produced

Glycolysis Location Cytosol of cell Outside mitochondria Cytosol – outside mitochondrion

Acetyl CoA Prep CO 2 removed from pyruvate NADH produced Coenzyme A added to acetyl group (2-C) Acetyl CoA produced Location = matrix of mitochondria

Krebs Cycle

Krebs Cycle - One Turn Acetyl group (2-C) added to oxaloacetate (4-C) forming citrate (6-C) 2 CO 2 lost 3 NAD+ reduced to 3 NADH 1 FAD reduced to 1 FADH 2 1 ATP produced by substrate level phosphorylation Oxaloacetate regenerated

Krebs Cycle – 1 Glucose – 2 Turns 4 CO 2 lost 6 NAD+ reduced to 6 NADH 2 FAD reduced to 2 FADH 2 2 ATP produced by substrate level phosphorylation

Krebs Cycle Location = matrix of mitochondria

ETC & Oxidative Phosphorylation

NADH & FADH 2 pass electrons to molecules in electron transport chain Electrons passed from molecule to molecule When some molecules accept electrons they must also accept H+ H+ released into intermembrane space when electrons passed to next molecule

ETC & Oxidative Phosphorylation Energy from electrons used to move H+ into intermembrane space Electrons accepted by oxygen 2e- + 2H+ + ½ O 2  H 2 O

ETC & Oxidative Phosphorylation Channel proteins allow H+ to diffuse down concentration gradient ATP synthase uses KE of H+ moving down concentration gradient to add P to ADP making ATP

ATP Production Glycolysis 4 ATP (2 net) Substrate level phosphorylation Krebs 2 ATP Substrate level phosphorylation

ATP Production ETC & oxidative phosphorylation 2 NADH from glycolysis = 4 to 6 ATP 2 NADH from acetyl CoA prep = 6 ATP 6 NADH from Krebs cycle = 18 ATP 2 FADH 2 from Krebs cycle = 4 ATP

ATP Production Total = 36 to 38 ATP per glucose