Biological Membranes

Question 1

membrane receptors are usually ________ to facilitate __________.

Answer 1

transmembrane
initiate messenger cascade

Question 2

list the main 4 cell-cell junctions found in epithelial animal cells

Answer 2

gap junctions
tight junctions
desmosomes
hemidesmosomes

Question 3

diffusion and osmosis rely solely on…

Answer 3

the concentration gradient of the compound of interest.

Question 4

A Vm means…

Answer 4

a state that is incapable of responding the stimuli

Question 5

Nernst Equation

Answer 5

E = 61.5/z • log([ion out]/[ion in])

Question 6

list the sphingolipids

Answer 6

ganglioside
ceramide
sphingomyelin
cerebroside

Question 7

lipid rafts

Answer 7

collections of similar lipids with or without associated proteins that serve as attachment points for other biomolecules

Question 8

lipids traveling between membrane layers

Answer 8

energetically unfavorable
requires the assistance of flippases

Question 9

FA

Answer 9

CA that contain a hydrocarbon chain and a terminal carboxyl group

Question 10

triacylglycerols

Answer 10

storage lipids

Question 11

water-soluble groups on P group of glycerophospholipid

Answer 11

choline (lecithin) and inositol

Question 12

sphingolipids

Answer 12

also have hydrophilic and hydrophobic regions

Question 13

cholesterol

Answer 13

• steroid derived from cholesterol
• hydrophilic and hydrophobic region
• the whole freezing prevention and fluidity thing

Question 14

waxes are found…

Answer 14

in the cell membranes of plants, protection and waterproofing

Question 15

integral proteins

Answer 15

embedded and transmembrane

Question 16

membrane associated (peripheral) proteins

Answer 16

electrostatic interactions w membrane esp lipid rafts or attached to integral proteins

like g proteins

Question 17

carbs are generally hydro________

Answer 17

philic

Question 18

role of carbs on phospholipid membrane

Answer 18

signaling and recognition, water coat

Question 19

cell-adhesion molecules

Answer 19

• comprise cell junctions
• allow cells to recognize each other
• cell differentiation and development
• direct pathways of communication

Question 20

gap junctions

Answer 20

pores connecting two cells forming a hydrophilic channel allowing for cell-cell communication (solutes and water)

6 molecules of connexin

Question 21

tight junctions

Answer 21

• paracellular route
• epithelial cells
• form a single tissue layer through which cells communicate
• form continuous bands around cells and allow for transepithelial voltage difference based on differing concentrations of ions

Question 22

desmosomes

Answer 22

• bind adjacent cells bu anchoring to their cytoskeletons
• interface between epithelial cells
• interactions between transmembrane proteins and filaments of adjacent cells

Question 23

hemidesmosomes

Answer 23

basement membrane anchoring

Question 24

pinocytosis

Answer 24

endocytosis of fluids and dissolved particles

Question 25

inner mitochondrial membrane

Answer 25

• restricted permeability
• cristae not porous
• ETC and ATP synthesis
• integral proteins
• no cholesterol, instead cardiolipin

Question 26

GHK voltage equation

Answer 26

Vm = 61.5log[Σ(Px • [X +/-])out/in / (Px • [X +/-])in/out)]

Na out, K out, Cl in