BMSC 200 Module 9 Exam Questions
with Correct Answers
what does dynamic mean? - ANSWER-constant turn over of the components in the
membranes
what are membranes primarily composed of? - ANSWER-lipids and proteins
more active membranes have what? - ANSWER-a higher ratio of protein
lipids include what? - ANSWER-phospholipids, glycosphingolipids and sterols
membrane composition varies considerably across what? - ANSWER-species and
cell types
cells have a mechanism to control lipid ______ and _______ - ANSWER-production,
localization
plasma membrane lipids are _______ distributed - ANSWER-asymmetrically
what does it indicate if the lipids are asymmetrically distributed? - ANSWER-
indicates the ability to place and maintain membrane lipids in a specific orientation
outer leaf of red blood cells has what? - ANSWER-choline containing lipids
inner leaf of red blood cells are rich in? - ANSWER-phosphatidylserine,
ethanolamines, and inositols
positioning can be dynamic to serve ______ roles which leads to what? - ANSWER-
physiological roles which leads to movement of phosphatidylserine to outer leaf
functions in blood clot formation and initiating cell destruction
what are the three classes of membrane proteins? - ANSWER-different mechanisms
and degrees of association with the membrane
1. peripheral
2. integral (trans-membrane proteins)
3. lipid-anchored
peripheral membrane proteins associate with membrane through? - ANSWER-
charge-charge or h-bonding interactions to integral proteins or membrane lipids
change in pH or ionic strength often does what? - ANSWER-releases these proteins
from the membrane
, peripheral membrane proteins may functional physiologically as what? - ANSWER-
regulators or tethers for integral membrane proteins
membrane proteins are _____ and usually span the membrane - ANSWER-
immersed
how are membrane proteins extracted from the membrane? - ANSWER-detergents
protein positioning within a membrane is? - ANSWER-specific and directional
transmembrane region _____. intra and extracellular domain _____ - ANSWER-
hydrophobic, hydrophilic
what are the two structural types of integral membrane proteins? - ANSWER-alpha-
helical bundles and beta-barrels
polar unpaired carbonyl and amide groups in the non-polar bilayer core are what?
therefore what? - ANSWER-energetically unfavourable, therefore carbonyl and
amide groups of the protein backbone inside the bilayer are hydrogen-bonded
integral membrane proteins lipid soluble portions of the protein span the _____ -
ANSWER-membrane
integral membrane proteins have ____ orientatin - ANSWER-specific
integral membrane proteins membrane spanning region is often what? - ANSWER-a
hydrophobic alpha helix
integral membrane proteins have different classes depending on what? - ANSWER-
the number and direction of membrane spanning regions
it is difficult to determine the 3D structures of membrane proteins but what can be
predicted from the amino acid sequence? - ANSWER-membrane spanning regions
stretches of ___ hydrophobic residues in a row are likely ______ _____ - ANSWER-
20, membrane spanning
a hydropathy index looks at what? - ANSWER-the hydrophobic characteristics of a
protein to predict transmembrane regions
tyrosine and tryptophan are often positioned at what? between what? - ANSWER-at
the interface between the polar face and the non-polar intermembrane region
charged amino acids are located where? - ANSWER-in the regions of the protein
that are in contact with the aqueous phase
lipids which are covalently attached to the protein can serve as what? - ANSWER-
anchors to link the protein to the membrane
with Correct Answers
what does dynamic mean? - ANSWER-constant turn over of the components in the
membranes
what are membranes primarily composed of? - ANSWER-lipids and proteins
more active membranes have what? - ANSWER-a higher ratio of protein
lipids include what? - ANSWER-phospholipids, glycosphingolipids and sterols
membrane composition varies considerably across what? - ANSWER-species and
cell types
cells have a mechanism to control lipid ______ and _______ - ANSWER-production,
localization
plasma membrane lipids are _______ distributed - ANSWER-asymmetrically
what does it indicate if the lipids are asymmetrically distributed? - ANSWER-
indicates the ability to place and maintain membrane lipids in a specific orientation
outer leaf of red blood cells has what? - ANSWER-choline containing lipids
inner leaf of red blood cells are rich in? - ANSWER-phosphatidylserine,
ethanolamines, and inositols
positioning can be dynamic to serve ______ roles which leads to what? - ANSWER-
physiological roles which leads to movement of phosphatidylserine to outer leaf
functions in blood clot formation and initiating cell destruction
what are the three classes of membrane proteins? - ANSWER-different mechanisms
and degrees of association with the membrane
1. peripheral
2. integral (trans-membrane proteins)
3. lipid-anchored
peripheral membrane proteins associate with membrane through? - ANSWER-
charge-charge or h-bonding interactions to integral proteins or membrane lipids
change in pH or ionic strength often does what? - ANSWER-releases these proteins
from the membrane
, peripheral membrane proteins may functional physiologically as what? - ANSWER-
regulators or tethers for integral membrane proteins
membrane proteins are _____ and usually span the membrane - ANSWER-
immersed
how are membrane proteins extracted from the membrane? - ANSWER-detergents
protein positioning within a membrane is? - ANSWER-specific and directional
transmembrane region _____. intra and extracellular domain _____ - ANSWER-
hydrophobic, hydrophilic
what are the two structural types of integral membrane proteins? - ANSWER-alpha-
helical bundles and beta-barrels
polar unpaired carbonyl and amide groups in the non-polar bilayer core are what?
therefore what? - ANSWER-energetically unfavourable, therefore carbonyl and
amide groups of the protein backbone inside the bilayer are hydrogen-bonded
integral membrane proteins lipid soluble portions of the protein span the _____ -
ANSWER-membrane
integral membrane proteins have ____ orientatin - ANSWER-specific
integral membrane proteins membrane spanning region is often what? - ANSWER-a
hydrophobic alpha helix
integral membrane proteins have different classes depending on what? - ANSWER-
the number and direction of membrane spanning regions
it is difficult to determine the 3D structures of membrane proteins but what can be
predicted from the amino acid sequence? - ANSWER-membrane spanning regions
stretches of ___ hydrophobic residues in a row are likely ______ _____ - ANSWER-
20, membrane spanning
a hydropathy index looks at what? - ANSWER-the hydrophobic characteristics of a
protein to predict transmembrane regions
tyrosine and tryptophan are often positioned at what? between what? - ANSWER-at
the interface between the polar face and the non-polar intermembrane region
charged amino acids are located where? - ANSWER-in the regions of the protein
that are in contact with the aqueous phase
lipids which are covalently attached to the protein can serve as what? - ANSWER-
anchors to link the protein to the membrane
