Cell size

cell size

high surface area to volume ratio is good

volume of a cube

• l x w x h

• length x width x height

surface area of a cube

• 2(lxw) + 2(lxh) + 2(wxh)

• 2(length x width) + 2(length x height) + 2(width x height)

• if all sides are the same 6s²

volume of a cylinder

• hπr²

• (height)π(radius²)

surface area of a cylinder

• 2πrh + 2πr²

• 2π(radius)(height) + 2π(radius²⁾

volume of a sphere

• 4/3πr²

• 4/3π(radius²)

surface area of a sphere

• 4πr²

• 4π(radius²)

larger cells

• more energy to function

• more space for substances to travel and waste to be excreted

• less efficient

• lower SA:V ratio

smaller cell

• less energy to function

• less space for substances to travel and waste to be excreted

• more efficient

• higher SA:V ratio

surface area

determines the rate that substances enter or exit the cell

volume

determines the amount of nutrients and oxygen the cell needs and the amount of waste it produces 

ratio formula

surface area/volume : 1

growth in cell

• volume increases faster than surface area

• volume is three dimensional, whereas surface area is two dimensional

• lower SA:V ratio as size increases

decrease in SA:V ratio

• decreases as size increase

• volume increases faster than surface area

most desirable shape for high SA:V ratio

• sphere for a large cell

• irregular pattern (usually shaped in a splatter) because it has more surface area

high SA:V ratio

• good

• more effecient exchange of substances

low SA:V ratio

• bad 

• less efficient exchange of substances

• cell could die

.

overall size is the same but the SA : VOL is larger

.

would die since it would not be able to get enough food or remove enough waste

long cells

high SA:V ratio

spherical cells

• lower SA:V ratio

• tend to be smaller