lab 7: aerobic cellular respiration and 20f222.jpg pea
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Lab 7: Aerobic Cellular
Respiration
http://www.astronomynotes.com/nature/spr06flowers/red/red3.jpg AND http://aqualandpetsplus.com/Live%20F222.jpg
Pea plants Zophobus morio larvae
I. Cellular Respiration (Intro)
• Cells require ATP in order to function.
• Cellular respiration is the “metabolic machinery that releases energy from food molecules”.
Organic compoundsFood
CarbohydratesProteins
Lipids
ATP(energy)
Oxidized
(Loose electrons in form of H atoms)
I. Cellular Respiration: Anaerobic vs. Aerobic
Anaerobic Respiration (ex. fermentation, lactic acid fermentation)
does not require oxygen for the production of ATP.
Aerobic Respiration requires oxygen for the
production of ATP.
Certain organisms can perform both Anaerobic and Aerobic respiration
depending on the availability of Oxygen.
I. Cellular Respiration: Anaerobic vs. Aerobic
Certain organisms can perform both Anaerobic and Aerobic respiration
depending on the availability of Oxygen.
Yeast Cells can 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).
Yeast Cells, in the absence of oxygen can produce ATP by alcoholic fermentation.
I. Cellular Respiration: Anaerobic vs. Aerobic
glucose 2 CO2 + 2C2H5OH (ethanol) + 2 ATPenzymes
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).
glucose 2 CO2 + 2C3H6O3 (lactic acid) + 2 ATPenzymes
II. Aerobic Respiration: Whole Organism
• Aerobic respiration at the whole organism level = process by which gases are exchanged with the environment.
O2
CO2
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
II. Aerobic Respiration: Whole Organism
In unicellular aquatic protozoans: O2 dissolved in water passes across the cell membrane by diffusion, and CO2 exits.
O2
CO2
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.Elodea cell
O2 CO2
Planarian
http://www.cdb.riken.jp/jp/04_news/img/planarian300.jpg
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.
spiracle
Spiracles
SEM
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.
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
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.
II. Aerobic Respiration: Cellular
• Cells of most organisms, including plants, carry out aerobic cellular respiration 24 hours per day.
C6H12O6 + 6O2 6CO2 + 6H2O + 36 ATP + HeatEnzymes
60% of energy from glucose is trapped in
ATP
40% of energy from glucose is lost as heat
Endothermic animals use this heat for regulating
body temperature
Glucose
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.
C6H12O6 + 6O2 6CO2 + 6H2O + 36 ATP + HeatEnzymes
products producedreactants consumed
In lab you will be measuring the rate of reactants consumed.
II. Aerobic Respiration: Cellular
1
Glycolysis
II. Aerobic Respiration: Cellular
1
– enzyme catalyzed– energy releasing– takes place in cell cytoplasm
(prokaryotic and eukaryotic cells)C6H12O6 2 Pyruvic acid molecules + 2 NADH + 2 ATP
Glycolysis
II. Aerobic Respiration: Cellular
1
Glycolysis
II. Aerobic Respiration: Cellular
2
Preparation step
II. Aerobic Respiration: Cellular
1
– occurs in fluid matrix of mitochondria (eukaryotic organisms)
2 Pyruvic acid mols CO2 + NADH + 2 Carbon compounds
Preparation step
II. Aerobic Respiration: Cellular
2
Preparation step
II. Aerobic Respiration: Cellular
3
Kreb’s Cycle
II. Aerobic Respiration: Cellular
1
– enzyme catalyzed– occurs in fluid matrix of mitochondria
(eukaryotic organisms)
2 Carbon Compound CO2 + ATP + FADH2 + NADHAcetyls
Kreb’s Cycle
II. Aerobic Respiration: Cellular
3
Kreb’s Cycle
II. Aerobic Respiration: Cellular
E- transport and Chemiosmosis4
II. Aerobic Respiration: Cellular
1
– 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
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
E- transport and Chemiosmosis4
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