Lecture 2

Question 1

amphiphilic molecule consisting of 2 lipid molecules attached to 2 of the OH groups of a glycerol molecule with a phosphate group attached at the third OH group; hydrophilic phosphate head group interacts with water, while the hydrophobic fatty acid tails exclude water

Answer 1

phospholipids`

Question 2

lipids with a carb chain attached

Answer 2

glycolipids

Question 3

produced in most nucleated cell that are potent, short-acting signaling molecules and function through paracrine or autocrine signals

Answer 3

prostaglandins

Question 4

plasma membranes of cells contain combinations of glycosphingolipids and proteins receptors organized in glycoprotein microdomains

Answer 4

lipid raft

Question 5

artificially prepared vesicle composed of a lipid bilayers; can be used to administer and transport nutrients and pharmaceutical drugs in the body

Answer 5

liposomes

Question 6

specialized intercellular connection linking most animal cell-types that directly connects the cytoplasm of 2 cells

Answer 6

gap junction

Question 7

spherical fragments derived/shed from the plasma of cells and are involved in intracellular communication between transport proteins, mRNA, and miRNA between cells

Answer 7

microvesicles (exosomes)

Question 8

family of transmembrane lipid transporter enzymes located in the membrane responsible for aiding the movement of phospholipid molecules between the 2 leaflets comprising a cell membrane

Answer 8

flippases/floppases

Question 9

most biological membranes have a different phospholipid composition for the 2 leaflets of the bilayer

Answer 9

membrane asymmetry

Question 10

tendency of nonpolar substances to aggregate in aqueous solution and exclude water molecules; driving force behind the folding of proteins, the formation of lipid bilayers and micelles, and the insertion of membrane proteins into the nonpolar lipid environment

Answer 10

hydrophobic effect

Question 11

used to separate different membrane bound compartments like mitochondria and nucleus

Answer 11

ultracentrifugation

Question 12

used to separate biological membranes containing lipids (lower density) from proteins (higher density)

Answer 12

density gradient ultracentrifugation

Question 13

has a greater resolving power due to the use of electrons that have shorter wavelengths

Answer 13

electron microscopy

Question 14

uses fluorescence and phosphorescence to study properties of organic and inorganic substances

Answer 14

fluorescence microscopy

Question 15

very high-resolution type of scanning probe microscopy, with demonstrated resolution on the order of fractions of a nanometer

Answer 15

atomic force microscopy

Question 16

increase the risk of coronary heart disease by raising LDL levels and lowering HDL levels

Answer 16

trans fat

Question 17

infects cells by binding the ACE2 metalloprotease present on the extracellular surface of airway epithelial cells; binding leads to membrane fusion and entry of viral genome into the cell where it can replicate; hand washing solubilizes the viral membrane and removes spike proteins that bind to ACE2

Answer 17

coronavirus

Question 18

the 3 OH groups that are the basic component of phospholipids that are sites for side chain attachment

Answer 18

glycerol backbone

Question 19

usually o-linked to a charged group and amide-linked to an acyl group such as fatty acid; replaces glycerol in some cases

Answer 19

sphingosine backbone

Question 20

aa can diffuse across membranes ; T/F

Answer 20

False

Question 21

Hydrophobic compounds can diffuse across membranes T/F

Answer 21

True

Question 22

O2, N2, H2O and CO2 can not diffuse across membranes T/F

Answer 22

False

Question 23

Charged molecules can diffuse through lipid bilayer T/F

Answer 23

False

Question 24

common structural feature of transmembrane regions of integral membrane proteins

Answer 24

alpha helix

Question 25

enveloped virus attaches to the cell membrane of recipient cell via receptors and receptors on the surface of the virus, followed by fusion where the evelope blends with the cell membrane and releases its contents (genome) into the cell

Answer 25

membrane fusion

Question 26

DNA viruses, RNA viruses, retroviruses

Answer 26

enveloped viruses containing human pathogens