2.5 Biological membranes

Question 1

What are the functions of membranes?

Answer 1

Control movement of substances in and out of cell/organelle

Question 2

What is the Fluid Mosaic Model?

Answer 2

A model representing cell membrane function and structure

Question 3

What is Diffusion?

Answer 3

The random passive movement of non-polar lipid soluble molecule from an area of high concentration to an area of low concentration

Question 4

What is facilitated Diffusion?

Answer 4

Transport of polar molecules across a membrane via Channel Proteins

Question 5

What is Osmosis?

Answer 5

the diffusion of water molecules from an area of high water potential
to an area of low water potential via a partially permeable membrane.

Question 6

What is Active Transport?

Answer 6

Transport of all molecules across membrane from an area of low concentration to an area of high concentration via carrier proteins using energy from ATP

Question 7

What is Exocytosis and Endocytosis?

Answer 7

Exocytosis - substances exiting cell via vesicle
Endocytosis - substances entering cell via CSM made vesicle

Question 8

What three factors increase rate of Gas Exchange?

Answer 8

Surface Area increase
Diffusion Distance decrease
Diffusion gradient becomes more steep