Studied by 1 person
lateral diffusion rate
The ________ of a mobile protein in a pure phospholipid bilayer or isolated plasma membrane is similar to that of lipids.
porin monomer
In a(n) ________, the outward- facing side groups on each of the B strands are hydrophobic and form a nonpolar ribbonlike band that encircles the outside of the barrel.
smallest cells
Prokaryotes, which represent the simplest and ________, are about 1- 2 m in length.
peroxisomal oxidation
The energy released during ________ is converted into heat, and the acetyl groups are transported into the cytosol.
Glycophorin
________ A**: the major protein in the erythrocyte plasma membrane, is a representative single- pass transmembrane protein, which contains only one membrane- spanning* B* helix.
pure bilayers
In ________, phospholipids do not spontaneously migrate, or flip- flop, from one leaflet to the other.
impermeable barrier
First, the** hydrophobic** core is a(n) ________ that prevents the diffusion of water- soluble** (hydrophilic**) solutes across the membrane.
Cholesterol
________ and its derivatives constitute the third important class of membrane lipids, the** steroids**
transport proteins
Specific membrane ________ in the plasma membrane permit the passage of nutrients into the cell and metabolic wastes out of it.
small molecules
The plasma membrane is highly permeable to water but poorly permeable to salts and ________ such as sugars and amino acids.
extraction of plasma membranes
Lipids** may be organized within the leaflets was the discovery that the residues remaining after the ________ with detergents contain two lipids:** cholesterol** and** sphingomyelin**
ribosome
A(n) ________ that fabricates such a protein is bound to the rough ER by the nascent polypeptide chain of the protein.
Domains
________ resemble other water- soluble proteins in their amino acid composition and structure.
two dimensional plane
In the ________ of a bilayer, thermal motion permits lipid molecules to rotate freely around their long axes and to diffuse laterally within each leaflet.
E coli
The porins in the outer membrane of a(n) ________ cell provide channels for the passage of disaccharides and other small molecules as well as phosphate.
typical animal cell
Lysosomes vary in size and shape, and several hundred may be present in a(n) ________.
plasma membrane
The ________ is intimately engaged in the assembly of cell walls, which in plants are built primarily of cellulose.
eukaryotic cells
All ________ contain a discernible amount of rough ER because it is needed for the synthesis of plasma- membrane proteins and proteins of the extracellular matrix.
cytoplasm
The ________ is the part of the cell outside the largest organelle, the nucleus.
initial stages of platelet
In the ________ stimulation by serum, phosphatidylserine is briefly translocated to the exoplasmic face.
OH containing
In other phosphoglycerides, a(n) ________ molecule such as ethanolamine, serine, and the sugar derivative inositol is linked to the phosphate group.
Lysosomes
________ are a great example of the ability of intracellular membranes to form closed compartments in with the composition of the lumen differs substantially from that t= of the surrounding cytosol.
Lipid
________- anchored proteins are just one example of membrane proteins that are asymmetrically located with respect to the faces of cellular membranes.
Biochemical
________ and microscopic evidence supports the existence of lipid rafts in natural membranes.
Peroxisomes
________ contain several oxidases- enzymes that use molecular oxygen to oxidize organic substances.
Acidic Organelles
PLAP
Although ________ and other GPI- anchored proteins lie in the opposite membrane leaflet from acyl- anchored proteins, both types of membrane proteins are concentrated in lipid rafts.
own distinctive proteins
The cytosol, the aqueous part of the cytoplasm outside all of the organelles, also contains its ________.
lipid bilayer
The ________ has two important properties.
acid pH
The ________ helps to denature proteins, making them accessible to the action of the lysosomal hydrolases, which themselves are resistant to acid denaturation.
Endoplasmic Reticulum
cytosolic leaflet
Phosphatidylserine** also is normally most abundant in the ________ of the plasma membrane.
fatty acyl chain
The plasmalogens are a group of phosphoglycerides that contain one ________, attached to glycerol by an ester linkage, and one long hydrocarbon chain, attached to glycerol by an ether linkage (C- O- C)
Natural membranes
________ from different cell types exhibit a variety of shapes, which complement a cells function.
usual physiologic temperatures
At ________, the hydrophobic interior of natural membranes generally has a low viscosity and a fluidlike, rather than gel- like, consistency.
animal cells
All ________ (except erythrocytes) and many plant cells contain peroxisomes.
lipid composition
Differences in ________ may also correspond to the specialization of membrane function.
relative abundance
The ________ of a particular phospholipid in the two leaflets of a plasma membrane can be determined on the basis of its susceptibility to hydrolysis by phospholipases.
terminal glycine
A group of cytosolic proteins is anchored to the cytosolic face of a membrane by a fatty acyl group (e.g., myristate or palmitate) attached to the** N- ________** residue.
artificial membranes
In both natural and ________, a typical lipid molecule exchanges place with its neighbors in a leaflet about 107 times per second and diffuse several micrometers per second at 37oC.
derivatives of glycerol
Phosphoglycerides**, the most abundant class of lipids in most membranes, are ________ 3- phosphat.
phospholipid molecule
As a(n) ________ diffuses from the bilayer into the channel, the enzyme- bound Ca2+ binds to the phosphate in the head group, thereby positioning the ester bond to be cleaved next to the catalytic site.
phospholipid bilayer
Membrane proteins** are defined by their location within or at the surface of a(n) ________.
Secondary lysosomes
________, which are larger and irregularly shaped, appear to result from the fusion of primary lysosomes with other membrane- bounded organelles and vesicles.
Ion channels
________ compose a second large and important family of multipass transmembrane proteins.
Soluble proteins
________ exhibit hundreds of distinct localized folded structures or motifs.
Primary lysosomes
________ are roughly spherical and do not contain obvious particulate or membrane debris.
transmembrane proteins
In all ________ examined to date, the membrane- spanning domains consist of one or more helices or of multiple* B* strands.
Rough Endoplasmic Reticulum
The ________: Ribosomes bound to the rough ER synthesize certain membrane and organelle proteins and virtually all proteins to be secreted from the cell.
GPI
Treatment of cells with phospholipase C releases ________- anchored proteins such as Thy- 1 and placental alkaline phosphatase (PLAP) from the cell surface.
