Cell Membrane and Transport Flashcards
What surrounds all cells?
cell membrane
Cell membrane functions
regulates what enters and leaves, protects and supports cell, communicate w cell
phospholipid bilayer
2 layers of phospholipid on cell membranes which protects and repels molecules `
hydrophilic part of phospholipid
head on the outside touching the water
hydrophobic part of phospholipid
tail on the inside of cell membrane, away from water
selectively permeable
only allows certain things to pass through
cell membrane main properties
flexible, self-repairing, can be divided, selectively permeable, contains protein channels for certain molecules
cell transport
movement across the cell membrane
what is allowed in cell?
Depends on: size, electrical charge, concentration, needs of cells
types of transport
Passive and active transport
what is passive transport?
Transport of molecules from high to low concentrations using simple diffusion, facilitated diffusion and osmosis without the use of ATP
Simple Diffusion
When molecules don’t have a charge and are small enough to pass through the phospholipid bilayer
facilitated diffusion
diffusion with the aid of protein channels + carrier proteins
protein channel
open for smaller, molecules to pass through with the addition of hormones
carrier proteins
for larger charged molecules
Compare simple diffusion to facilitated diffusion
while both simple and facilitated diffusion move molecules from high to low concentrations, facilitated diffusion uses transport proteins to assist molecules when moving from high to low
osmosis
diffusion of water high to low concentrations
hypertonic
solute with high concentration outside of cell causing cell to shrink/shrivel up and die
hypotonic
solute with a low concentration outside of cell causing cell to expand/explode and die
isotonic
equal amounts of solute and water = equilibrium causing a normal looking cell
hypertonic plant
plasmolysed
hypertonic animal
creanated
hypotonic plant
turgid
hypotonic animal
lysed
