Lab 7: Aerobic Cellular Respiration

1. Lab 7: Aerobic Cellular Respiration Pea plants Zophobus morio larvae http://www.astronomynotes.com/nature/spr06flowers/red/red3.jpg AND http://aqualandpetsplus.com/Live%20F222.jpg

2. Oxidized (Loose electrons in form of H atoms) Organic compounds Food Carbohydrates Proteins Lipids ATP (energy) I. Cellular Respiration (Intro) • Cells require ATP in order to function. • Cellular respiration is the “metabolic machinery that releases energy from food molecules”.

3. I. Cellular Respiration: Anaerobic vs. Aerobic Anaerobic Respiration (ex. fermentation, lactic acid fermentation) does not require oxygen for the production of ATP. Aerobic Respirationrequires oxygen for the production of ATP. Certain organisms can perform both Anaerobic and Aerobic respiration depending on the availability of Oxygen.

4. I. Cellular Respiration: Anaerobic vs. Aerobic Certain organisms can perform both Anaerobic and Aerobic respiration depending on the availability of Oxygen. Yeast Cellscan perform aerobic respiration or alcoholic fermentation Human Muscle Cells can perform aerobic respiration OR when starved for oxygen, as in during vigorous exercise, muscle cells can switch to producing ATP by lactic acid fermentation (cause of lactic acid buildup).

5. enzymes glucose 2 CO2 + 2C2H5OH (ethanol) + 2 ATP enzymes glucose 2 CO2 + 2C3H6O3 (lactic acid) + 2 ATP I. Cellular Respiration: Anaerobic vs. Aerobic Yeast Cells, in the absence of oxygen can produce ATP by alcoholic fermentation. Human Muscle Cells, when starved for oxygen as in during vigorous exercise, can switch to producing ATP by lactic acid fermentation (cause of lactic acid buildup).

6. II. Aerobic Respiration: Whole Organism • Aerobic respiration at the whole organism level = process by which gases are exchanged with the environment. O2 CO2

7. II. Aerobic Respiration: Whole Organism • Respiratory Surface (= part of the organism where O2 diffuses into and CO2 diffuses out of the organism) must be moist, as gases must be dissolved in water before they can diffuse in or out. http://www.go-epix.net/uploadedimages/Water%20drop%20ks16870%208050114134057.JPG

8. II. Aerobic Respiration: Whole Organism In unicellular aquatic protozoans: O2 dissolved in water passes across the cell membrane by diffusion, and CO2 exits. CO2 O2

9. II. Aerobic Respiration: Whole Organism In multicellular aquatic plants and invertebrate animals: O2 dissolved in water enters cells by diffusion, and CO2 exits by diffusion. Planarian CO2 O2 Elodeacell http://www.cdb.riken.jp/jp/04_news/img/planarian300.jpg

10. II. Aerobic Respiration: Whole Organism In insects: O2 enters through small openings in the body wall (spiracles) and is carried through tracheal tubes to moist cell membranes, across which respiratory exchange occurs. Spiracles spiracle SEM

11. II. Aerobic Respiration: Whole Organism In fish: O2 (in H2O) diffuses across the surface of gills, into capillaries of the circulatory system and CO2 diffuses in the opposite direction.

12. II. Aerobic Respiration: Whole Organism In terrestrial vertebrates: O2 diffuses across moist epithelial cells in the internal alveoli of the lungs. CO2 diffuses in the opposite direction. O2 CO2

13. II. Aerobic Respiration: Whole Organism In multicellular terrestrial flowering plants: O2 (in H2O) diffuses across the surface of roots and stems, and CO2 diffuses in the opposite direction. Leaves possess specialized cells (guard cells) which open and close stomates, regulating gas exchange.

14. Enzymes C6H12O6 + 6O2 6CO2 + 6H2O + 36 ATP + Heat II. Aerobic Respiration: Cellular • Cells of most organisms, including plants, carry out aerobic cellular respiration 24 hours per day. 60% of energy from glucose is trapped in ATP Glucose 40% of energy from glucose is lost as heat Endothermic animals use this heat for regulating body temperature

15. Enzymes C6H12O6 + 6O2 6CO2 + 6H2O + 36 ATP + Heat In lab you will be measuring the rate of reactants consumed. II. Aerobic Respiration: Cellular To measure the rate of respiration one can either 1) measure the rate of reactants consumed, or 2) measure the rate of products produced. reactants consumed products produced

16. II. Aerobic Respiration: Cellular Glycolysis 1

17. II. Aerobic Respiration: Cellular • enzyme catalyzed • energy releasing • takes place in cell cytoplasm (prokaryotic and eukaryotic cells) Glycolysis 1 C6H12O6 2 Pyruvic acid molecules + 2 NADH + 2 ATP

18. II. Aerobic Respiration: Cellular Glycolysis 1

19. II. Aerobic Respiration: Cellular Preparation step 2

20. II. Aerobic Respiration: Cellular • occurs in fluid matrix of mitochondria (eukaryotic organisms) Preparation step 1 2 Pyruvic acid mols CO2 + NADH + 2 Carbon compounds

21. II. Aerobic Respiration: Cellular Preparation step 2

22. II. Aerobic Respiration: Cellular Kreb’s Cycle 3

23. II. Aerobic Respiration: Cellular • enzyme catalyzed • occurs in fluid matrix of mitochondria (eukaryotic organisms) Kreb’s Cycle 1 2 Carbon Compound CO2 + ATP + FADH2 + NADH Acetyls

24. II. Aerobic Respiration: Cellular Kreb’s Cycle 3

25. II. Aerobic Respiration: Cellular E- transport and Chemiosmosis 4

26. O2 is the final acceptor of electrons that were originally part of the glucose molecule. O2 combines with the electrons and H+ to form water. II. Aerobic Respiration: Cellular • electrons from NADH and FADH2 pass through a series of compounds and loose energy. • some energy is lost as heat • most of the energy is trapped at ATP through the process of chemiosmosis • occurs in cristae of the mitochondria (eukaryotes) or folds of the cell membrane (prokaryotes). E- transport and Chemiosmosis 1

27. II. Aerobic Respiration: Cellular E- transport and Chemiosmosis 4