Transcript Metabolism
Reading Logarithmic 100000 time (s) 15 40000 500000 275000 900 45 67 19 14 654 2.7 175000 6200 10000 rocks (No.) rocks (No.) 1000 100 10 1 23006 105004 85000 467 32 32 10 11 326 1 95000 3174 1 1 10 100 1000 time (s) 10000 100000 1000000 Surface Area to Volume Ratio Inversely proportional to size Length of r SA:V and allometry “Allometric” describes when there is a relationship between the size of organisms and any of their features. • This SA:V relationship is allometric. • So is the relationship between organism weight and SMR. Length of r SA:V and metabolism Total Metabolism • An elephant uses more O2 than a mouse, in an hour. • BUT a gram of mouse uses more O2 than a gram of elephant in an hour. Standard Metabolic Rate • Bigger individuals use more O2 than smaller individuals, per unit time. • Per gram body weight, smaller animals use more O2 than larger animals. SA:V and metabolism Can you describe more than one way in which a lower SA:V affects the metabolism of an animal? Ectothermy vs Endothermy (not warm or cold blooded) Did you know that metabolic rates in mammals = 10x those in reptiles? Endothermy is expensive! Metabolism How do you think ecologists use information on metabolism? Can you define… • Respiration: • Ventilation: • Metabolism: • Manometry: • SMR: • Endothermic: • Ectothermic: Can you define… • Respiration: Role of O2 in extracting energy from organic compounds. • Ventilation: Pumping air into and out of the body. • Metabolism: Sum total of all chemical processes in the body. • Manometry: Method to measure and quantify metabolic rates. • SMR: Standard Metabolic Rate (mL O2/g/h). • Endothermic: Generates heat internally. • Ectothermic: Obtains heat from external sources. Can you answer… How did you estimate metabolic rates in lab? What is SMR? What is the difference between total metabolism and SMR? What is an advantage and a disadvantage of the tracheal system in insects? Can you answer… How did you estimate metabolic rates in lab? (You should know this!) What is SMR? Energy (O2) used per gram body weight in an individual. It is a function of body weight. You can measure through O2…or CO2 What is the difference between total metabolism and SMR? (You should think about this!) What is an advantage and a disadvantage of the tracheal system in insects? Did you read about Tidal flow The amount of air that passes in and out of the lung during normal respiration. What is the difference between total lung capacity and tidal volume? Take Home Message All of this boils down to what happens at a cellular level. Recall: When you bring oxygen into your system, you let that oxygen oxidize glucose. This takes energy out of storage and makes it available for ATP synthesis. Think about this, then think about the insect tracheal system and our own mammalian system again.