a&p1 diffusion and osmosis lab

what does the plasma membrane separate and regulate

the interior of the cell from the external environment. also regulates the passage of material in and out of the cell

what is the primary component of the plasma membrane

phospholipid, along with proteins and cholesterol.

phospholipid head is

polar and hydrophilic

phospholipid tail is

nonpolar and hydrophobic

what kind of permeable is the plasma membrane

selectively permeable

passive transport

requires no energy. movement of molecules follow a concentration gradient (high to low)

active transport

uses ATP. moves against concentration gradient (low to high)

solution

contains a solute and a solvent

solute

molecule that is dissolved into smaller molecules

solvent

the liquid in which a solute is dissolved

the more solute present in a solution,

the higher the concentration of the solute

diffusion

natural movement of a solute down a concentration gradient (high to low)

diffusion continues until..

equilibrium is reached

the rate of diffusion is affected by..

molecular weight, concentration gradient, temperature, membrane surface area, permeability

osmosis

diffusion of water across a selectively permeable membrane. water moves from area of low solute concentration (high water) to area of high solute concentration (low water) until equilibrium is reached

when does osmosis occur

when the solute cannot move across a concentration due to a barrier (like cell membrane)

hypotonic

when a cell is placed in solution with a lower solute concentration, causing water to rush in, leading to swelling and bursting (lyse)

isotonic

equal concentration in the cell

hypertonic

if a cell is placed in a solution with high solute concentration, water will leave cell, causing it to crenate (shrink)