8. Membranes

Question 1

What makes up the glycoprotein coat?

Answer 1

carbs + membrane bound proteins

Question 2

What are flippases? (ex: flippase, floppase, scramblase)

Answer 2

Enzymes that flip phospholipids to other side of membrane (ex: flips to one side, flips to other side, flips 2 simul)

Question 3

What are lipid rafts?

Answer 3

collection of lipids w/ or w/o associated proteins that serve as attachment point for biomolecs

Question 4

Transmembrane vs embedded vs integral vs peripheral/membrane associated proteins

Answer 4

go thru entire membrane vs embedded on either interior or exterior side of membrane vs collective term of transmembrane and embedded vs electrostatically bound to membrane

Question 5

Membrane receptors tend to be what type of integral proteins?

Answer 5

transmembrane

Question 6

Gap junctions vs tight junctions vs desmosomes vs hemidesmosomes

Answer 6

aka connexons made up of connexin, direct cell to cell communication by connecting cytoplasms vs prevents solutes from leaking out into space b/w cells via paracellular route vs act as spot welds to attach adjacent cells by anchoring their cytoskeletons vs act as spot welds to attach epithelial cells to underlying structures

Question 7

Ex of passive transport vs active transport

Answer 7

simple and facilitated diffusion, osmosis vs primary (Na/K ATPase) and secondary active transport (ATP synthase from ETC), requires a membrane protein

Question 8

osmotic pressure formula. Osmotic pressure is what property?

Answer 8

PI = iMRT
i = van Hoff factor - # of molec when dissolved in soln (ex: glucose = 1, NaCl = 2 b/c Na+ and Cl- in soln)
M = molarirty
R = ideal gas constant
T = temp in K
osmotic pressure is a colligative property (dependent on # of molec, not chemical identity)
Higher osmotic pressure means more water flows

Question 9

Types of facilitated diffusion

Answer 9

carrier proteins (open 1 side except in occluded state - not open on either side), channel proteins (open both sides)

Question 10

primary vs secondary active transport

Answer 10

using ATP directly to transport molec across membrane, (ex: Na/K ATPase) vs using a nml conc gradient to transport molec up their conc gradient; aka coupled transport (ex: ATP synthase from ETC)

Question 11

pinocytosis vs phagocytosis

Answer 11

endocytosis of fluids and dissolved particles vs solids

Question 12

The electric potential vs resting potential can be calculated by what two eqns?

Answer 12

Nernst eqn vs Goldman-Hodgkin-Katz voltage eqn