Lab 7: Aerobic Cellular Respiration AND 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 compounds Food Carbohydrates Proteins 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 CO 2 + 2C 2 H 5 OH (ethanol) + 2 ATP enzymes 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 CO 2 + 2C 3 H 6 O 3 (lactic acid) + 2 ATP enzymes

II. Aerobic Respiration: Whole Organism Aerobic respiration at the whole organism level = process by which gases are exchanged with the environment. O2O2 CO 2

II. Aerobic Respiration: Whole Organism Respiratory Surface (= part of the organism where O 2 diffuses into and CO 2 diffuses out of the organism) must be moist, as gases must be dissolved in water before they can diffuse in or out.

II. Aerobic Respiration: Whole Organism In unicellular aquatic protozoans: O 2 dissolved in water passes across the cell membrane by diffusion, and CO 2 exits. O2O2 CO 2

II. Aerobic Respiration: Whole Organism In multicellular aquatic plants and invertebrate animals: O 2 dissolved in water enters cells by diffusion, and CO 2 exits by diffusion. Elodea cell O2O2 CO 2 Planarian

II. Aerobic Respiration: Whole Organism In insects: O 2 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: O 2 (in H 2 O) diffuses across the surface of gills, into capillaries of the circulatory system and CO 2 diffuses in the opposite direction.

II. Aerobic Respiration: Whole Organism In terrestrial vertebrates: O 2 diffuses across moist epithelial cells in the internal alveoli of the lungs. CO 2 diffuses in the opposite direction. O2O2 CO 2

II. Aerobic Respiration: Whole Organism In multicellular terrestrial flowering plants: O 2 (in H 2 O) diffuses across the surface of roots and stems, and CO 2 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. C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O + 36 ATP + Heat Enzymes 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. C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O + 36 ATP + Heat Enzymes 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) C 6 H 12 O 6 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 CO 2 + 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 CO 2 + ATP + FADH 2 + NADH Acetyls Kreb’s Cycle

II. Aerobic Respiration: Cellular 3 Kreb’s Cycle

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

II. Aerobic Respiration: Cellular 1 –electrons from NADH and FADH 2 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 O 2 is the final acceptor of electrons that were originally part of the glucose molecule. O 2 combines with the electrons and H+ to form water.

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