Cellular Respiration Let’s Review

1. Cellular Respiration Let’s Review • Is a chemical process that uses oxygen to convert chemical energy stored in organic molecules into another form of chemical energy – a molecule called ATP • Cells in plants and animals then use the ATP as their main energy supply.

2. Energy • The ability to perform work • Ex: your heart muscle does work every time it beats • Two basic forms of energy • Potential • kinetic

3. Potential Energy • Is stored energy due to an object’s position or arrangement

4. Kinetic Energy • Energy of motion • Anything that is moving • Kinetic - “motion”

5. Thermal Energy • Energy that has been transferred • From areas that are warmer to cooler

6. Chemical Energy • Organic compounds store energy (potential) in the way their atoms are arranged. • This is called chemical energy

7. ATP - Nature's Energy Store All living things, plants and animals, require a continual supply of energy in order to function. The energy is used for all the processes which keep the organism alive.

8. Before the energy can be used, it is first transformed into a form which the organism can handle easily. This special carrier of energy is the molecule adenosine triphosphate, or ATP.

9. Its Structure • The ATP molecule is composed of three components. • At the center is a sugar molecule, ribose • (the same sugar that forms the basis of RNA).

10. Attached to one side of this is a base (a group consisting of linked rings of carbon and nitrogen atoms); in this case the base is adenine. The other side of the sugar is attached to a string of phosphate groups. These phosphates are the key to the activity of ATP.

11. ATP consists of a base, in this case adenine (red), a ribose (magenta) and a phosphate chain (blue).

12. How it works • ATP works by losing the endmost phosphate group when instructed to do so by an enzyme. • This reaction releases a lot of energy, which the organism can then use to build proteins, contact muscles, etc

13. The reaction product is adenosine diphosphate (ADP),

14. ATP

15. ADP

16. Even more energy can be extracted by removing a second phosphate group to produce adenosinemonophosphate (AMP).

17. AMP

18. When the organism is resting and energy is not immediately needed, the reverse reaction takes place and the phosphate group is reattached to the molecule using energy obtained from food or sunlight. • he ATP molecule acts as a chemical 'battery', storing energy when it is not needed, but able to release it instantly when the organism requires it.

19. The Phosphorus Cycle • The fact that ATP is Nature's 'universal energy store' explains why phosphates are a vital ingredient in the diets of all living things. Modern fertilizers often contain phosphorus compounds that have been extracted from animal bones.

20. These compounds are used by plants to make ATP. We then eat the plants, metabolise their phosphorus, and produce our own ATP. When we die, our phosphorus goes back into the ecosystem to begin the cycle again...

21. Cellular Respiration

22. glucose ATP Cellular Respiration • A catabolic, exergonic, oxygen (O2)requiring process that uses energyextracted from macromolecules (glucose) to produce energy (ATP)and water (H2O). C6H12O6 + 6O2 6CO2 + 6H2O + energy

23. Question: • In what kinds organisms does cellular respiration take place?

24. Plants and Animals • Plants - Autotrophs: self-producers. • Animals - Heterotrophs: consumers.

25. Inner membrane space Matrix Cristae Outer membrane Inner membrane Mitochondria • Organelle where cellular respirationtakes place.

26. Breakdown of Cellular Respiration • Three main parts (reactions). 1. Glycolysis (splitting of sugar) a. cytosol, just outside of mitochondria.

27. Breakdown of Cellular Respiration 2. Krebs Cycle (Citric Acid Cycle) a. mitochondrial matrix 3. Electron Transport Chain (ETC a.. inner mitochondrial membrane.

28. 1. Glycolysis • Occurs in thecytosol just outside of mitochondria. • Two phases: A. Energy investment phase a. Preparatory phase B. Energy yielding phase a. Energy payoff phase

29. Glucose (6C) C-C-C-C-C-C 2ATP 2 ATP - used 0 ATP - produced 0 NADH - produced 2ADP + P C-C-C C-C-C Glyceraldehyde phosphate (2 - 3C) (G3P or GAP) 1. Glycolysis A. Energy Investment Phase:

30. Glyceraldehyde phosphate (2 - 3C) (G3P or GAP) GAP GAP C-C-C C-C-C 4ADP + P 0 ATP - used 4 ATP - produced 2 NADH - produced 4ATP C-C-C C-C-C (PYR) (PYR) Pyruvate (2 - 3C) (PYR) 1. Glycolysis B. Energy Yielding Phase

31. 1. Glycolysis • Total Net Yield 2 - 3C-Pyruvate (PYR) 2 - ATP 2 - NADH

32. Mitochondrial Matrix 2. Krebs Cycle (Citric Acid Cycle) • Location:mitochondrial matrix. • Acetyl CoA (2C)bonds to Oxalacetic acid (4C - OAA)to make Citrate (6C). • It takes 2 turnsof the krebs cycle to oxidize1 glucosemolecule.

33. 1 Acetyl CoA (2C) OAA (4C) Citrate (6C) Krebs Cycle 2 CO2 FADH2 (one turn) 3 NAD+ FAD 3 NADH ATP ADP + P 2. Krebs Cycle (Citric Acid Cycle)

34. 2 Acetyl CoA (2C) Citrate (6C) OAA (4C) Krebs Cycle 4 CO2 2 FADH2 (two turns) 6 NAD+ 2 FAD 6 NADH 2 ATP 2 ADP + P 2. Krebs Cycle (Citric Acid Cycle)

35. 2. Krebs Cycle (Citric Acid Cycle) • Total net yield(2 turnsof krebs cycle) 1.2 - ATP (substrate-level phosphorylation) 2. 6 - NADH 3. 2 - FADH2 4. 4 - CO2

36. Inner Mitochondrial Membrane 3. Electron Transport Chain (ETC) andOxidative Phosphorylation (Chemiosmosis) • Location:inner mitochondrial membrane. • Uses ETC and ATPSynthase(enzyme) to make ATP. • ETCpumps H+ (protons) across innermembrane (lowers pH in innermembrane space).

37. 3. Electron Transport Chain (ETC) andOxidative Phosphorylation (Chemiosmosis) • TheH+then moves via diffusion through ATP Synthase to make ATP. • All NADH and FADH2converted to ATP during this stage of cellular respiration. • Each NADH converts to 3 ATP. • Each FADH2 converts to 2 ATP (enters the ETC at a lower level than NADH).

38. ATP TOTAL ATP YIELD 1. 04 ATP – glycolysis and krebs cycle 2. 34 ATP - ETC 38 ATP - TOTAL YIELD

39. Glucose Cytosol Mitochondria Krebs Cycle Glycolysis 2 Acetyl CoA 2 Pyruvate 2NADH 2 ATP (substrate-level phosphorylation) 6NADH 2FADH2 2NADH ETC and Oxidative Phosphorylation 2 ATP (substrate-level phosphorylation) 2ATP 4ATP 6ATP 18ATP 4ATP 2ATP Maximum ATP Yield for Cellular Respiration (Eukaryotes) 36 ATP (maximum per glucose)

40. Fermentation • Occurs in cytosol when “NO Oxygen”is present (called anaerobic). • Remember: glycolysis is part of fermentation. • Two Types: 1. Alcohol Fermentation 2. Lactic Acid Fermentation

41. 2ADP + 2 2ATP C C C C CC P 2NADH 2 NAD+ C C C C C Glycolysis 2 Ethanol 2 Pyruvic acid 2CO2 released 2 NAD+ 2NADH glucose Alcohol Fermentation • Plants and Fungi  beer and wine

42. 2ADP + 2 2ATP C C C C CC P 2NADH 2 NAD+ C C C C C C Glycolysis 2 Lactic acid 2 Pyruvic acid 2 NAD+ 2NADH Glucose Lactic Acid Fermentation • Animals (pain in muscle after a workout).

43. Lactic Acid Fermentation • End Products: Lactic acid fermentation 2 - ATP 2 - Lactic Acid molecules

44. Alcohol Fermentation • End Products: Alcohol fermentation 2 - ATP 2 - CO2 2 – molecules of ethanol

45. Question: • In addition to glucose, what other various food molecules are use in Cellular Respiration?

46. Catabolism of VariousFood Molecules • Other organic molecules used for fuel. 1. Carbohydrates: polysaccharides 2.Fats: glycerol’s and fatty acids 3. Proteins: amino acids