Biological Membranes

Question 1

What are lipid rafts?

Answer 1

section of membrane containing similar lipids that are often involved in signaling; they may also include proteins as attach points

Question 2

what are cell adhesion molecules (CAM)?

Answer 2

protein that allow cells to recognize one another, form cell-cell junctions

Question 3

what are gap junctions?

Answer 3

gap junctions allow the transport of water and solute between cells through pores made of connexin protein

Question 4

what are tight junctions?

Answer 4

tight junctions tightly bind cells together and prevent the flow of solutes/molecules through the intracellular space (paracellular route).

they form the epithelium and line renal tubules - transfer of solutes in nephron must go through cells and cellular contro.

Question 5

what are desmosomes?

Answer 5

they bind cells together through transmembrane proteins that are connected to intermediate filaments in the cell.

they are found at the interface of different layers of epithelial tissue

Question 6

what’s the difference between a carrier protein and a channel protein? what type of transport do they engage in?

Answer 6

carrier proteins and channel proteins engage in facilitated diffusion

carrier proteins are only open to one side of the membrane at a time (revolving door and occluded state) whereas channel proteins when in the open conformation are open to both sides