Cellular Respiration

AP Biology

The Equation

C6H12O6 + 6O2 6CO2 + 6H20 + ATP

C6H12O6 = glucose

6O2 = oxygen gas

6CO2 = carbon dioxide

6H20 = water

ATP = energy

Redox Reaction

C6H12O6 Loses electronsOxidized to CO2

O2

Gains electronsReduced to H2O

What happens…..

High energy electrons (e-)Stripped from C6H12O6 Used to do work - create H+ concentration

gradientFinally accepted by oxygen (O2)

Mitochondria

Site of cellular respirationStructure

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

CristaeLarge surface area for ETC

Mitochondria

Relating structure to functionMatrix

Segregates chemicals of Krebs cycle

NADH Production

Enzymes dehydrogenasesRemove 2 hydrogens (2 H+ and 2 e-) from

substrateAdd 2 electrons and 1 H+ to NAD+

2 e- + 1 H+ + NAD+ NADHNAD+ reduced

Glycolysis

Glycolysis

Glycolysis

Energy investmentUses 2 ATP moleculesSplits glucose

Glycolysis

Energy yielding4 ATP molecules produced by substrate

level phosphorylation2 pyruvate (3-C) producedElectrons transferred to NAD+2 NADH produced

Glycolysis

LocationCytosol of cellOutside mitochondria

Cytosol – outside mitochondrion

Acetyl CoA Prep

CO2 removed from pyruvateNADH producedCoenzyme A added to acetyl group (2-C)Acetyl CoA producedLocation = matrix of mitochondria

Krebs Cycle

Krebs Cycle

Krebs Cycle - One Turn

Acetyl group (2-C) added to oxaloacetate (4-C) forming citrate (6-C)

2 CO2 lost3 NAD+ reduced to 3 NADH1 FAD reduced to 1 FADH2

1 ATP produced by substrate level phosphorylation

Oxaloacetate regenerated

Krebs Cycle – 1 Glucose – 2 Turns

4 CO2 lost6 NAD+ reduced to 6 NADH2 FAD reduced to 2 FADH2

2 ATP produced by substrate level phosphorylation

Krebs Cycle

Location = matrix of mitochondria

ETC & Oxidative Phosphorylation

ETC & Oxidative Phosphorylation

ETC & Oxidative Phosphorylation

NADH & FADH2 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 O2 H2O

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

Glycolysis4 ATP (2 net)Substrate level phosphorylation

Krebs2 ATPSubstrate level phosphorylation

ATP Production

ETC & oxidative phosphorylation2 NADH from glycolysis = 4 to 6 ATP2 NADH from acetyl CoA prep = 6 ATP6 NADH from Krebs cycle = 18 ATP2 FADH2 from Krebs cycle = 4 ATP

ATP Production

Total = 36 to 38 ATP per glucose