1. Energy

2. Energy Chapter 8 –Oxidation-Reduction –ATP

3. Oxidation-Reduction What is a covalent bond?

4. Oxidation-Reduction Is it easy to form?

5. Oxidation-Reduction Energy is stored in the bonds between atoms –Most energy on earth comes from the sun –Photosynthesis is the process by which the sun’s energy is converted into stored in bonds between atoms in complex sugar molecules

6. Oxidation-Reduction Chemical reactions involve transferring energy stored in chemical bonds to new bonds Electrons can also be transferred during chemical reactions

7. Oxidation-Reduction Oxidation: The process by which an atom loses an electron

8. Oxidation-Reduction Reduction: The process by which an atom gains an electron

9. Oxidation Oxygen attracts electrons Often accepts electrons during cellular processes

10. Oxidation Oxygen attracts electrons Often accepts electrons during cellular processes Oxidation is oxygen “stealing” an electron from the atom of interest

11. Reduction What charge does an electron carry?

12. Reduction If an atom gains an electron what happens to the charge of that atom?

13. Reduction When an atom gains an electron its charge becomes more negative aka. that atom is reduced

14. Oxidation-Reduction Electrons are never lost entirely: they just exchange ownership Oxidations and reductions always take place together Reactions of this nature are referred to as Redox reactions

15. Oxidation-Reduction Redox reactions are the process by which energy is transferred between molecules The reduced form of a molecule has a higher energy than the oxidized form

16. Oxidation-Reduction Electrons carry energy with them when they pass from molecule to molecule Energy possessed by an electron depends on the distance between the electron and the nucleus of the atom

17. Oxidation-Reduction Electrons can gain energy by moving further from the nucleus Moved by light or other energy

18. Oxidation-Reduction When energized electrons move to another atom they take that energy with them

19. Oxidation-Reduction The energy can be released by moving the electron back to its original distance from the nucleus

20. Oxidation-Reduction Our studies describe critical cell processes which rely on the energy from redox reactions These processes are the keys to life on this planet

21. Energy Process ☼ Oxidation-Reduction –ATP

22. ATP Adenosine Triphosphate

23. ATP Structure

24. ATP

25. ATP

26. ATP Energy is stored in the bonds between the phosphate groups Energy is released when the bonds are broken

27. ATP The resulting molecule (ADP) can have phosphate groups re-attached to be used again

28. ATP There are 7 kcal energy stored one bond between phosphate groups –7 kcal are released when the bond is broken –7 kcal are required to form the bond ADP + P i 7 kcal ATP 7 kcal