Energetic Metabolism Observing the Effects of Respiration and Photosynthesis

Interconnections: Photosynthesis & Respiration

Chemical Equations AerobicAerobic Respiration C 6 H 12 O 6 C 6 H 12 O 6 + 6O 2 6O 2  6CO 2 6CO 2 + 6H 2 O 6H 2 O + energy PhotosynthesisPhotosynthesis 6CO 2 6CO 2 + 6H 2 O 6H 2 O + light energy  C 6 H 12 O 6 C 6 H 12 O 6 + 6O 2 Measure O 2 use Measure O 2 production

Metabolic Rate Speed of aerobic respiration in an organism (use of O 2 )Speed of aerobic respiration in an organism (use of O 2 ) Measured in CaloriesMeasured in Calories –unit of energy –amount of heat required to increase temperature of 1 kg of H 2 O by 1 o C –1 liter of O 2 consumption = Calories Our experiment measures metabolic rate as mL O 2 /gram/day, which can be converted to caloriesOur experiment measures metabolic rate as mL O 2 /gram/day, which can be converted to calories

Factors Affecting Metabolic Rate Body TemperatureBody Temperature Hypotheses: Do plants or animals have a higher metabolic rate? How do environmental temperatures influence metabolic rates? Mealworms are ectothermic animals

Experimental Set Up soda lime cheesecloth peas mealworms Pipettes for peas: 1-mL at 15 o C 5-mL at 30 o C Pipettes for mealworms: 5-mL at both 15 and 30 o C

Reading the Respirometer Pipettes For 1-mL pipette 0.1 mL between numbers 0.01 mL between smallest lines 1 mL 0.1 mL For 5-mL pipette 1 mL between numbers 0.1 mL between smallest lines

Calculations Suppose the total amount of O 2 consumed in 30 minutes by 15.6 grams of mealworms was 3.5 mL.Suppose the total amount of O 2 consumed in 30 minutes by 15.6 grams of mealworms was 3.5 mL. Calculation of mL O 2 /gram/dayCalculation of mL O 2 /gram/day 3.5 mL 30 min x 60 min 1 hour x 24 hours 1 day x _____1______ weight in grams = 10.8 ml O 2 /gram/day x 1 = 15.6 grams x 24 hours 1 day 3.5 mL 30 min 1 x 60 min 1 hour 2

Graphing: Histogram Plot the class averages for pea and mealworm metabolic rates at both temperatures.

2.1 mL gram day More Calculations (see page 62) Suppose the metabolic rate of your peas was 2.1 mL O 2 / gram/daySuppose the metabolic rate of your peas was 2.1 mL O 2 / gram/day Calculation of the calorie intake of a 150 pound student whose metabolic rate matches the peasCalculation of the calorie intake of a 150 pound student whose metabolic rate matches the peas x calories 1000 mL x grams = calories/day 150 x = grams x calories 1000 mL 2.1 mL gram day x grams

Photosynthesis Experiment Hypothesis Will the rate of photosynthesis be increased by increased light energy?

Experimental Set Up Syringe Elodea bicarbonate solution 1-mL pipette For 1-mL pipette 0.1 mL between numbers 0.01 mL between smallest lines

Graphing Photosynthesis Data Plot the oxygen produced for light at 50 cm and 25 cm for each timed reading.

Graphing Photosynthesis Data Use separate lines to connect the sets of points.

CLEAN UP! Return your mealworms, peas, and elodea to the appropriate containersReturn your mealworms, peas, and elodea to the appropriate containers Put used soda lime in discard bottlePut used soda lime in discard bottle Clean and dry your respirometers.Clean and dry your respirometers. Discard cheesecloth into the trashDiscard cheesecloth into the trash Make sure the sinks stay cleanMake sure the sinks stay clean

Worksheet Complete pages from lab manualComplete pages from lab manual Be sure your instructor checks your completed worksheet before you leave the labBe sure your instructor checks your completed worksheet before you leave the lab