L6 Cell Anatomy: Membrane bound organelles

Which is NOT a function of membranes?

Which statements about the plasma membrane are CORRECT?

Cholesterol acts as a fluidity buffer for the plasma membrane as it makes the phospholipid layer more viscous, but also lowers its solidifying point,

Proteins are unspecific to cell type.

There are two types of transport in regards to energy transfer: passive and active. Passive is from [blank_start]high to low[blank_end] concentration, "[blank_start]down[blank_end]" a gradient. Active is from [blank_start]low to high[blank_end] concentration, "[blank_start]up[blank_end]" a gradient.

Facilitated diffusion is a form of [blank_start]passive[blank_end] transport where molecules are too large to diffuse through a membrane on their own. Facilitated diffusion involves [blank_start]channels, or carrier proteins[blank_end]. Channels can be "leak" channels where molecules can [blank_start]freely[blank_end] move, or they can be gated. Voltage-gated channels respond to changes in [blank_start]charge[blank_end] whereas ligand-gated channels respond to [blank_start]chemical signals[blank_end].

Active transport utilises [blank_start]proteins[blank_end] that act as pumps which use [blank_start]ATP[blank_end] to move molecules [blank_start]up[blank_end] a concentration gradient. This is important for maintaining [blank_start]concentration[blank_end] of ions, and can be direct or indirect. A classic example is the [blank_start]sodium-potassium[blank_end] pump.

Which of the following is not a function of proteins?