Figure 3.3 r=1 um _=1m Surface area(4元r2)=12.6μm2 Volume(3πr3)=4.2um3 Surface Volume 3 r=2 um r=2um Surface area 50.3 um2 Volume 33.5 um3 Surfac Volum 2=1.5 Relative to cell volume,small cells contain more surface area than do large cells:higher surface-to-volume(S)ratio高比表面积 2012 Pearson Education,Inc.Figure 3.3 r = 1 m r = 2 m r = 1 m r = 2 m Surface area (4r 2 ) = 12.6 m2 Volume ( r 3 ) = 4.2 m3 Surface area = 50.3 m2 Volume = 33.5 m3 3 4 Surface Volume = 3 Surface Volume = 1.5 © 2012 Pearson Education, Inc. Relative to cell volume, small cells contain more surface area than do large cells: higher surface-to-volume (S/V) ratio高比表面积