1. REDOX reactions in respiration

2. Equations for aerobic respiration All of these are fine!....

3. Equation for Cellular Respiration 6CO 2 + 6H 2 0 + e - + 36-38 ATP + heat C 6 H 12 O 6 + 6O 2 YIELDS

4. What are REDOX reactions in respiration? ‘REDOX’ means ‘oxidation and reduction’ You can’t have one without the other REDOX reactions involve ELECTRON TRANSFER Organic molecules contain lots of energy locked in their covalent bonds Redox reactions TRANSFER this bond energy in the form of ELECTRONS to ELECTRON CARRIERS which can temporarily store it and move it to ultimately synthesise ATP

5. Energy metabolism and REDOX reactions REDOX (oxidation-reduction) reactions play a key role in energy flow through organisms This is because the electrons flowing from one molecule to another are carrying energy with them

7. REDOX reactions OXIDATIONREDUCTION Loss of electronsGain of electrons Gain of oxygenLoss of oxygen Loss of hydrogenGain of hydrogen Results in C-O bondsResults in C-H bonds Results in a compound with lower potential energy Results in a compound with higher potential energy OIL RIG LEO says GER

8. REDOX reactions in respiration Cells tap energy from electrons transferred from organic fuels to oxygen Glucose gives up energy as it is oxidized: it transfers its electrons (and energy) to water The protons follow the electrons to produce water Loss of hydrogen atoms Energy Gain of hydrogen atoms

9. Enzymes remove electrons from glucose molecules and transfer them to a coenzyme Hydrogen carriers such as NAD + and FED shuttle electrons in redox reactions OXIDATION Dehydrogenase and NAD + REDUCTION

12. NADH delivers electrons to a series of electron carriers in an electron transport chain As electrons move from carrier to carrier, their energy is released in small quantities Redox reactions release energy when electrons “ fall ” from a hydrogen carrier to oxygen Energy released and now available for making ATP ELECTRON CARRIERS of the electron transport chain Electron flow

14. Glycolysis: Always the initial stage of respiration Location: cytoplasm Substrate: glucose Requires input of 2 ATP Products: pyruvate, (NADH), 4 ATP Glycolysis is an anaerobic process: no oxygen required the movie...

17. Summary of glycolysis 1.Occurs in the cytoplasm of the cell 2.Two ATP molecules are used to start the process (‘energy investment phase’) 3.A total of 4 ATP’s are produced (net gain of 2 ATP) 4.2 molecules of NADH are produced 5.Involves substrate level phosphorylation, lysis, oxidation and ATP formation 6.Controlled by enzymes: when ATP levels in the cell are high, feedback inhibition will block the first enzyme in the pathway 7.Produces 2 pyruvate molecules at the end