Cellular Respiration

1. Cellular Respiration

2. Cellular Respiration • Process that makes energy for all life on earth • It is the transfer of chemical bond energy of organic molecules to the chemical bond energy of ATP • Remember: • Making chemical bonds stores energy • Breaking chemical bonds releases energy • Respiration breaks the bonds of glucose, so it releases energy

3. ATP food ATP + 6CO2 + 6H2O  C6H12O6 + 6O2 glucose+oxygenenergy+carbon+ water dioxide O2 Harvesting energy stored in food • Cellular respiration • breaking down food to produce ATP • in mitochondria • using oxygen • “aerobic” respiration • usually digesting glucose • but could be other sugars, fats, or proteins

4. Both plant and animal cells carry out the final stages of cellular respiration in the mitochondria. Intermembrane space Outer membrane Mitochondrion PlantlCells Inner membrane Animal Cells Matrix

5. Using ATP to do work? • Can’t store ATP • too unstable • only used in cell that produces it • only short term energy storage • carbohydrates & fats are long term energy storage ATP work Adenosine TriPhosphate Adenosine DiPhosphate ADP A working muscle recycles over 10 million ATPs per second

6. { • energy needed even at rest • activity • temperature control { • growth • reproduction • repair { • glycogen(animal starch) • fat A Body’s Energy Budget 1 make energy eatfood ATP 2 synthesis (building) 3 storage

7. ADP vs. ATP

8. ATP Factoid • On average, the human body contains 250 grams of ATP • The amount of ATP used by the human body in a day equals the body weight of the individual.

9. Cellular Respiration • Occurs in 3 Distinct Phases • The first stage, glycolysis, is anaerobic—no oxygen is required. • The last two stages are aerobic and require oxygen to be completed. SUMMARY EQUATION:

10. STAGES OF CELLULAR RESPIRATION • Respiration occurs in three main stages High-energy electrons carried by NADH GLYCOLYSIS ELECTRONTRANSPORT CHAIN KREBSCYCLE Cytoplasmicfluid Mitochondrion

11. GlycolysisGlyco=sweet, sugarlysis= to split Glycolysis: a series of chemical reactions in the cytoplasm of a cell that break down glucose, a six-carbon compound, into two molecules of pyruvic acid, a three-carbon compound • produces two ATP molecules for each glucose molecule broken down. • 2 molecules of NADH are formed

12. The Transition Phase *(we’ll include this as part of Kreb’s) • Before Krebs Cycle and electron transport chain can begin, pyruvic acid undergoes a series of reactions in which it gives off a molecule of CO2 and combines with a molecule called coenzyme A to form acetyl-CoA. Acetyl CoA(acetyl coenzyme A) Pyruvicacid CO2

13. Glycolysis Summary • Produces 2 ATP • 2 ATP were needed for the reaction • 4 ATP were made in the reaction • Creates 2 NADH molecules • Passed to Electron Transport Chain • Glucose (6 C’s) has been broken down to form 2 molecules of pyruvic acid (3 C’s) • Converted into Acetyl CoA

14. The Krebs Cycle • Series of reactions that occurs in mitochondrial matrix • Breaks pyruvic acid down into CO2, releasing energy • For every one turn of the cycle, one molecule of ATP, two molecules of carbon dioxide, 3 NADH, 1 FADH2 are produced. • Per molecule of glucose, Kreb’s creates: • 2 ATP • 6 NADH • 2 FADH2 • 4 CO2 CO2

15. Other Energy Molecules… • NAD and FAD • Hydrogen and electron carriers • Bring hydrogen/electrons to the electron transport chain where they are used to make more ATP • Hydrogen and Electrons are sources of potential energy • Energy can be released to make ATP

16. The electron transport chain • In the electron transport chain, the carrier molecules NADH and FADH2 give up electrons that pass through a series of reactions. Oxygen is the final electron acceptor forming water. • This sets up a H+ (proton) gradient • Allow the protons to flow through ATP synthase which synthesizes ATP (ADP + Pi = ATP)

17. ETC continued… • The electron transport chain adds 32 ATP molecules to the four already produced during glycolysis & Krebs cycle • Occurs in the inner mitochondrial membrane

18. ETC • Located in the Mitochondria • Produces 32 ATP • For each pair of Hydrogen atoms brought in by: • NAD: 3 ATP molecules are made • FAD” 2 ATP molecules are made

19. food O2 ATP CO2 H2O In summary, what do we need to make energy? • The “Furnace” for making energy • mitochondria • Fuel • food:carbohydrates, fats, proteins • Helpers • oxygen • enzymes • Product • ATP • Waste products • carbon dioxide • then used by plants • water enzymes

20. Summary Facts : Cellular Respiration • Reactants/Raw materials : oxygen + sugar (glucose, starch, food, fats) • Energy Source: chemical bond energy of organic comp’ds • Products Made: carbon dioxide, water, ATP (energy) • When does it occur?: all the time, constantly, 24/7 • Location in the Cell: mitochondria • Organisms that use it: all living things