Download 100% Distilled Water 80% H 2 O 80% Water 20% Dissolved

Cellular Transport Notes
A. Review the functions of the cell (plasma) membrane. Regulates what enters and leaves the cell (homeostasis)
B. Do cells eat and drink? Explain.
1. Cells take in nutrients and water
2. Cells remove wastes
C. Name the part of the cell that allows it to take in nutrients and water and remove waste. Cell membrane
D. Name the two main structures that make up the cell membrane.
1. Proteins
2. Phospholipids
E. List the types of proteins found embedded in the cell membrane.
1. Receptor
2. Channel (Integral)
3. Marker (Glycoprotein)
F. Cells move substances through the cell membrane by the process called
1. Transport
2. Name the two forms of transport.
a. Passive transport also called diffusion
b. Active transport
G. Name the conditions needed for passive transport to occur.
1. Requires no energy from cell
2. Molecules move from high concentration to low concentration
3. Molecules move with or down the concentration gradient.
H. Define osmosis. Diffusion of water through a selectively permeable membrane.
I. Explain how osmotic conditions affect cells. Draw arrows to show the direction water will move across the membrane.
Below each beaker, draw the shape of the cell after the osmotic condition is reached, and name the osmotic condition.
80% H2O
80% H2O
100% Distilled
Water
80% H2O
70% Water
30% Dissolved
Substances
80% Water
20% Dissolved
Substances
J. Osmotic Conditions
1. Hypertonic solutions cause cells to lose water and the cell shrinks; example is salt water.
2. Hypotonic solutions cause cells to gain water and the cell swells; example is fresh water.
3. Isotonic solutions help cells maintain same size and shape, since water moves in and out across the membrane
in equal concentrations.
K. Define facilitated diffusion. Use of channel proteins to help with diffusion.
1. Is facilitated diffusion passive or active transport? It is active transport
2. What types of molecules move across the membrane using facilitated diffusion? Molecules that are unable to
diffuse across the cell membrane.
L. Name the conditions needed for active transport to occur.
1. It requires energy.
2. Molecules move from low concentration to high concentrations.
3. Molecules move against or up the concentration gradient.
M. Define the types of active transport.
1. Endocytosis is active transport whereby cells use the cell membrane to bring large particles into the cell.
Types of endocytosis:
a. Phagocytosis is ingestion of large particles by the cell membrane.
b. Pinocytosis occurs when the cell draws in small molecules as the membrane pulls inward creating
vacuoles around the small molecules.
2. Exocytosis is active transport to remove wastes from the cell.
3. Protein pumps use ATP to move molecules across the membrane.