Energy

1. Energy

2. Energy • Chapter 8 • Oxidation-Reduction • ATP

3. Oxidation-Reduction • What is a covalent bond?

4. Oxidation-Reduction • What is a covalent bond? • 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 • Oxidation: The process by which an atom loses an electron • 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 • What charge does an electron carry? • 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 • When energized electrons move to another atom they take that energy with them • 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 • Structure

25. ATP • Structure

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 ATP 7 kcal 7 kcal ADP + Pi