cell membrane Flashcards
cell membrane
the outer boundary that seperates it from other cells.
determines what gets in and out of the cell
made up of a double layer of lipid molecules and protiens
what is homeostasis
body systems working together to ensure the cellular environment is kept constant
what is the 2 layers of phospholipids at the cell membrane called
bilayer
what are the 2 components of a phospholipid
hydrophobic tail + hydrophilic head
describe how the cell membrane is constructed
the bilayer has the heads on the outside and the tails on the inside. it also has channel proteins and carrier proteins
what is the function of a channel protein
to provide a pathway for hydrophilic particles to travel across the membrane without coming into contact with the hydrophobic tails
name the 4 functions of the cell membrane
- physical barrier
- regulates the passage of materials
- sensitive to changes
- helps support the cell
describe how the membrane physically supports the cell
the internal part of the membrane is connected to the cells microfilaments of the cells cytoskeleton.
there are also connectors to adjacent cells providing support to the whole tissue.
describe how the membrane regulates the passage of materials
it controls the movement of materials into and out of the cell
eg. entry of ions and nutrients, removal of wastes
The cell membrane regulates material passage through selective permeability, allowing some molecules to pass freely while others require transport proteins, and some need energy for movement across the membran
describe how the membrane is sensitive to changes
the first part of the cell affected by changes in the extracellular fluid is the membrane. it also has receptors that are sensitive to certain molecules that are in its immediate environment
describe how the membrane helps support the cell
it separates the cytoplasm from the extracellular fluid; its important because he composition of the 2 fluids is very different
