Cell Membrane Structure
Transport Types
Osmosis and Tonicity
Homeostasis
Challenge
100
What is the main structure of the cell membrane called?
The phospholipid bilayer
100
Movement of molecules without energy is called what?
Passive Transport
100
What type of solution is the highlighted cell in?
Hypotonic Solution
100
What is the main function of the cell membrane?
To regulate what enters and leaves the cell, maintaining homeostasis
100
The cell membrane is often compared to what in real life?
A security gate or selective barrier
200
Which is the hydrophilic part and hydrophobic part?
Hydrophilic = heads, Hydrophobic = tails
200
Is this active or passive transport?
Passive transport (facilitated diffusion)
200
What type of solution are these highlighted cells in?
Hypertonic Solution
200
What characteristic of life does the image represent in the cell?
The balance of internal conditions (homeostasis)
200
What process is being shown?
Exocytosis
300
Which type of molecule helps stabilize the membrane’s flexibility?
Cholesterol
300
Movement of water across a membrane is called what?
Osmosis
300
A cell placed in a solution with equal solute inside and out will…?
Stay the same size (isotonic)
300
Give an example of how cells maintain balance in solute concentrations.
Using active transport or osmosis to adjust levels inside and outside the cell
300
Q: What might happen if all cell membranes became fully permeable?
The cell would lose control of balance and die
400
WHat type of protein is below?
What is a transport (integral) protein?
400
What type of transport is this? 
Active Transport
400
Why does water move toward a hypertonic solution?
Because there is a higher solute concentration there; water moves to balance it out.
400
What happens if a cell cannot regulate transport correctly?
It may swell, shrink, or die (loss of homeostasis)
400
How does the sodium-potassium pump move ions (directions & energy use)?
Pumps sodium out and potassium in, using ATP energy
500
Explain the “fluid mosaic model” of the cell membrane.
The membrane is flexible, with proteins and lipids floating and moving within it like a mosaic.
500
What is the difference between facilitated diffusion and active transport?
Facilitated diffusion uses proteins but no energy; active transport uses proteins and energy (ATP).
500
Which way do sodium and potassium ions move in the sodium-potassium pump?
3 sodium ions move out, 2 potassium ions move in (using ATP).
500
How does active transport help maintain homeostasis?
It moves molecules against gradients to keep proper internal balance
500
What are all the colors you could get in a package of gummy bears?
Red,yellow,green,orange,clear