his2 Flashcards
(24 cards)
What is the cell membrane made of?
phospholipids,
cholesterol, and proteins
what is the membrane functions ?
1-work as a selective barrier regulating the passage
of materials into and out of the cell
2- facilitating the transport
of specific molecules
3-keep constant the ion content of cytoplasm
what is the membrane proteins function ?
perform a recognition and signaling function
playing a key role in the interactions of cell its environment
what is the function of plasma membrane proteins ?
link the exoskeleton and ECM AND ALLOW CONTINUOUS exchange of influences in both directions
what is the thickness of the membranes?
from 7.5 to 10 nm
The
line between adjacent cells sometimes seen faintly with the
light microscope consists of what?
plasma membrane proteins plus
extracellular material
Membrane phospholipids are amphipathic, consisting of what ?
two nonpolar (hydrophobic or water-repelling) long-chain
fatty acids linked to a charged polar (hydrophilic or waterattracting) head that bears a phosphate group
How are Phospholipids organized to be more stable?
double
layer (bilayer) with the hydrophobic fatty acid chains located
in a middle region away from water and the hydrophilic polar
head groups contacting the water
does the phospholipids in each half of the bilayer are
different?
yes,
what is the glycocalyx ?
oligosaccharide chains that extend outward from the
cell surface and contribute to a delicate cell surface coating
what is the location of Integral proteins?
incorporated directly within the lipid bilayer
what is the location of peripheral proteins ?
bound to one of the two membrane surfaces, particularly on the cytoplasmic side
how Peripheral proteins can be extracted ?
with salt solutions
how Peripheral proteins can be extracted ?
with salt solutions
how Peripheral proteins can be extracted ?
with salt solutions
how Peripheral proteins can be extracted ?
with salt solutions
how Peripheral proteins can be extracted ?
with salt solutions
how integral proteins can be extracted?
by using detergents
to disrupt the lipids
what is the function of plasma membrane ?
physical barrier
selective permeability
electrochemical gradients
communication
what is the plasma membran ?
the site where materials are
exchanged between the cell and its environment
Cells open and close specific channels for Na+, K+, Ca2+, and other ions in response to
physiological stimuli
فهم
Water molecules usually cross
the plasma membrane through channel proteins called what?
aquaporins
what is the carriers ?
transmembrane proteins that bind small
molecules and translocate them across the membrane
what is the carriers ?
transmembrane proteins that bind small
molecules and translocate them across the membrane
