Membrane vs Transude - What's the difference?

As a noun membrane

is a flexible enclosing or separating tissue forming a plane or film and separating two environments (usually in a plant or animal).

to pass through a pore, membrane or interstice.

(wikipedia membrane)

(en noun)

A flexible enclosing or separating tissue forming a plane or film and separating two environments (usually in a plant or animal).

A mechanical, thin, flat flexible part that can deform or vibrate when excited by an external force.

A flexible or semi-flexible covering or waterproofing whose primary function is to exclude water.