cell membrane Flashcards
What is the difference between intrinsic and extrinsic proteins?
intrensic proteins span the whole membrane extrensic proteins are only found on the surface of the membrane
why is the cell membrane described as a fluid mosaic model
phospholipids can move laterally throughout the layer making it fluid like and proteins are scattered around through out making it mosaic like
what is diffusion
the net movement of molecules from a reigion of high to low concentration down a consentration gradient through random movement
word for word
The fluid mosaic model of cell membranes was first proposed in 1972.
The vacuoles in beetroot cells contain molecules of betalain, a red pigment.
Betalains are large polar molecules.
These molecules can leave beetroot cells if the vacuole membrane and the cell surface
membrane are damaged.
Explain why betalain molecules cannot move through intact cell membranes.
betalain molecules are too big to pass through the cells membraine
there are no carrier proteins for betalain molecules to move through
brtalain molecules are polar and are repelled by the fatty acids hydrophobic tails
what does metabolic energy mean
energy released by respiration
Describe the role of carrier proteins in transport across the cell membrane.
bind to specific molecules and change shape to move the molecules across the membrane
substance a is a large polar molecule but cannot pass through a cell membrain explain why
substance x is too large to pass through the membrane
substance x is polar so the hydrophobic fatty acid tails repel it so it cant pass through
there are no chanel proteins for it to move through
Why can’t ions pass through the phospholipid bilayer directly?
ions are charged and hydrophillic so they cant pass through the bilayer as theyre repelled by hydrophillic tails
: How does a channel protein aid diffusion?
they form pores to allow substances to pass through the membrane
what do channel proteins form
pores
write the word facilitated 3 times pls
what is facilitated diffusion
the net movement of molecules from a reigon of high to low concentration down a concentration gradient through transport proteins without the use of proteins
