Download Hyper/Hypo/Isotonic Solutions

Cell Membrane Structure
• Phospholipid bilayer:
• a double layer of lipids makes up most of the cell
membrane.
• Proteins: many proteins are embedded in the
phospholipid bilayer
• Some act as channels to transport materials
through the membrane
• Some are connected to carbohydrate chains on
the exterior of the cell
• Carbohydrates:
• Short chains of carbohydrates are connected to
proteins or lipids on the exterior surface of the cell
• They act as markers to identify the cell
Selectively Permeable
• Cell membranes act as barriers,
controlling which materials enter and leave
the cell
• Materials can enter or leave the cell based
on their size and the amount of substance
present(concentration)
Cell Transport
PassiveTransport: small molecules can cross over
the cell membrane without using extra energy
Diffusion: small particles flow down a concentration gradient from an area of high
[concentration] to an area of [low]
Osmosis: the diffusion of water molecules over
the cell membrane
Facilitated Diffusion: particles still travel from
[high] to [low], but they pass through channels in the
membrane Example: ions
•Raw Egg Osmosis Demonstration
Types of Solutions and Movement
of Water
Hypertonic Solutions
• Hypertonic solutions have a HIGHER
concentration of solutes than what is inside the
cell
• This causes water to move
OUT of the cell.
• Hypertonic environments shrink
animal cells.
Hypotonic Solution
• Hypotonic solutions have a LOWER concentration of
solutes than what is inside the cell
• This causes water to move
INTO the cell.
• Hypotonic environments
swell animal cells.
Isotonic Solutions
• Isotonic solutions have THE SAME concentration of solutes as what is inside the cell
• While water will move in and out,
there is no NET movement of
molecules.
• Isotonic environments cause
no net change.
Cells in Hypertonic Solution
Cells in Hypotonic Solution
Normal Cells in Isotonic Solution
Active Transport
Active Transport requires additional energy, because
substances are being transported AGAINST the concentration gradient(from [low]  [high])
Endocytosis:
endo: within cyt: cell -osis: process of
the process of taking materials into a cell by
forming vesicles around the substance
pinocytosis: pin: to drink
cells taking in substances dissolved in water
phagocytosis: phag: to eat
cells taking in large particles
Exocytosis:
exo- from outside
the process of removing substances from the cell by
fusing internal vesicles with the cell membrane
• White Blood Cell Engulfing Bacteria