3.3.3 surface area: volume ratio Flashcards
what is the definition of volume
total space occupied by an organism
what is the definition of surface area
area of organism exposed to environment
do smaller organisms have a larger or smaller sa:v ratio
larger
how do you calculate volume of a cube
L x W x H
how do you calculate SA of a cube
(L x H) x number of faces
how do you calculate volume of a cuboid
L x W x H
how do you calculate SA of a cuboid
2 (LW) + 2 (LH) + 2 (HW)
how do you calculate volume of a cylinder
pi x radius(squared) x L
how do you calculate SA of a cylinder
2 pi radius(squared) + 2 pi radius L
what is metabolism
sum of all chemical reactions in an organism
small organisms have. a larger SA:V ratio… therefore…
they lose heat quicker to surroundings
they respite quickly to replace lost heat
must have metabolic rates to ensure that they don’t lose so much heat they they die
how are single celled organisms adapted for gas exchange
thin membrane
partially permeable membrane
large SA:V ratio
short diffusion pathway
what is the process by which oxygen reaches cells inside body
diffusion
