To provide the energy for nearly all life processes (such as synthesizing biomolecules, active transport, cell division, movement, etc.) such as glucose, and prior to that, from the sun for photosynthesis. The energy comes from foods 6CO2 + 12H2O + solar energy --> C6H12O6 + 6O2 + 6H2O C6H12O6 + 6O2 + 2ATP --> 38ATP + 6CO2 + 6H2O They are linked as a cycle. The products of one reaction are the reactants of the other.

What is ATP????? A modified ribonucleotide

Glucose - consumed as food and digested, brought to cells by blood Oxygen - inhaled into the lungs, brought to cells by hemoglobin in blood ATP - 2 energy molecules already available in the cells To generate ATP Anaerobic respiration and fermentation Phosphorylation

C6H12O6 + 6O2 + 2ATP --> 38ATP + 6CO2 + 6H2O

If all the energy in glucose were released at once, it would be wasted. Most of the energy would be lost all at once as heat, burning up the cell. Glycolysis Krebs cycle Electron transport chain Cytoplasm Mitochondria

The matrix of the mitochondria The cristae of the inner membrane of the mitochondria

Glycolysis Glyco = sugar lysis = to split or break - Occurs in the cytoplasm - Does not require oxygen Input: 1 glucose 2 ATP Output: 2 pyruvate 2 NADH 4 ATP

Substrate-Level Phosphorylation - ATP generated during glycolysis is formed by substrate-level phosphorylation - A high energy "donor" molecule directly transfers a phosphate group to ADP, forming ATP - Usually occurs with the help of an enzyme - Does not require an H+ gradient or ATP Synthase

hill.com/sites/ /student_view0/chapter25/ animatio n__how_glycolysis_works.html

Oxidation of Pyruvate - If oxygen is present, pyruvate will continue to be broken down - Before pyruvate can enter the Krebs Cycle, it is oxidized into acetyl CoA

Oxidation of Pyruvate - Pyruvate loses a carbon (leaves as CO2) - The broken bond is used to reduce NAD+ to NADH (charges up the molecule with two high energy electrons) - The remaining two carbons from the pyruvate bond to coenzyme A creating acetyl CoA - This happens to each pyruvate

Simple Oxidation of Pyruvate and Krebs Cycle

Krebs Cycle ( aka Citric Acid Cycle) Input: 2 acetyl CoA Output: 4 CO2 2 ATP 6 NADH 2 FADH2 hill.com/sites/ /student _view0/ chapter25/animation__how _the_krebs_cyc le_works__quiz_1 _.html

Simple Oxidation of Pyruvate and Krebs Cycle

Electron Transport Chain Input: 10 NADH 2 FADH2 6 O2 Output: 32 ATP 6 H2O

Electron Transport Chain INTERMEMBRANE SPACE NAD FADH2 ADP + Pi H+ 2e- + O + 2H+ --> H2O hill.com/sites/ /student_view0/chapter25/animation__electron_transport_system _and_atp_synthesis__q uiz_2_.html

C6H12O6 + 6O2 + 2ATP --> 38ATP + 6CO2 + 6H2O Glycolysis - cytoplasm Oxidation of pyruvate - mitochondrial matrix Kreb's Cycle - mitochondrial matrix Electron Transport Chain - cristae of mitochondrial inner membrane

Glycolysis Glucose 2 ATP 4 ATP 2 Pyruvate 2 NADH 2 CO2 exit as by-product and 2 NADH are produced

Kreb's Cycle Oxaloacetate CoA Citrate NADH FADH2 ATP ADP + Pi CO2 H2O FAD2+ NAD+

2e- + O + 2H+ Electron Transport Chain NADH FADH2 ATP ATP Synthase H+ Inner membrane Outer membrane Chemiosmotic

The set of reactions that require oxygen to break down pyruvate to generate ATP The fluid and space inside the inner membrane of the mitochondrion The biochemical pathway that breaks down 2 acetyl CoA to produce 4CO2, 2ATP, 6NADH, and 2FADH2 flavine adenine dinucleotide; a molecule that accepts electrons during redox reactions; FAD is the oxidized form

B C A D C

NADH; 3 NADH are produced in each turn making a total of 6 per glucose The electron transport chain reactions C6H12O6 + 6O2 + 2ATP --> 38ATP + 6CO2 + 6H2O The folding of the inner membrane provides a large surface area for the molecules of the electron transport chain. The area between the inner and outer membranes provides a confined space in which protons can accumulate, driving chemiosmosis.

Electron Transport Chain INTERMEMBRANE SPACE NAD FADH2 ADP + Pi H+ 2e- + O + 2H+ --> H2O