FNR 45400 Lecture Notes - Lecture 6: Spiral Valve, Eukaryote, Food Chain
Document Summary
Terms to know: surface area/volume ratio (sa/v)- the amount of surface area per unit volume of an object. Body size affects all free living organisms that must uptake metabolites for growth and dispose of waste/heat products through the body wall. The larger the organism the smaller the sa/v ratio. The relationship among sa/v, volume, and area can be seen in fig. 2, which shows that as surface area and volume increase, the sa/v ratio decreases. Therefore, larger animals have a harder time expelling waste than smaller organisms do. Likewise, the metabolic rate that can take place in an organism is dependent on a cell"s size. Smaller organisms will be able to maintain a higher metabolic rate than larger organisms because they have a larger sa/v ratio. If a whale could achieve the same metabolic rate as a bacterial cell, it would generate heat of 15000 degrees.