TRANSPORT ACROSS THE CELL MEMBRANE ACTIVE TRASPORT

EGGSCELLENT PASSIVE TRANSPORT Four raw eggs were soaked in vinegar (acetic acid) for two days. This process removes the shell (calcium carbonate). The outer layer is now a semi-permeable membrane. Calcium Carbonate + Acetic Acid  Calcium + Water + Carbon Dioxide 2) The eggs were then put in 4 different environments and left for 2 more days: vinegar, corn syrup, water with food dye, and filtered water. 3) The egg soaked in vinegar is the control of the experiment. It is the sample that no experiments are performed on – it is a blank slate that we can compare experimental results to. Examine the sample. Outline your observations here: __________________________________________________________________________________________________________________

4) Observe the eggs that were in the corn syrup and filtered water 4) Observe the eggs that were in the corn syrup and filtered water. Use a few words to describe each. Corn Syrup Egg: __________________________________________ Filtered Water Egg: _______________________________________ 5) Explain your observations using the words osmosis, semi-permeable, hypertonic, hypotonic, inside, outside, net movement, expand, shrink. Draw diagrams to support your answer. Corn Syrup Egg Filtered Water Egg

6) Do you think the dye was able to make it through the membrane? Hypothesis: __________________________________________ 7. Pop the egg and find out! 8. Explain your observations using the words high concentration, low concentration, concentration gradient, semi-permeable membrane, molecules, inside egg, outside egg. Draw a diagram to support your explanation.

Transport Processes Movement across the cell membrane Passive Transport Active Transport Substances move from high concentration to low concentration. No energy input required 3 Types: Simple Diffusion Facilitated Diffusion Osmosis Substances move from low concentration to high concentration. Energy input required 3 Types: Protein Assisted Endocytosis Exocytosis

ACTIVE TRANSPORT 1. Protein Assisted Sometimes the cell’s health depends on bringing substances in or pushing substances against the concentration gradient. Protein Pumps imbedded in the cell membrane pump particles from low concentration to high concentration. This requires energy, in the form of ATP!

ACTIVE TRANSPORT 2. Bulk Transport: Endocytosis Brings a “gulp” of fluid or larger particles into the cell (like single-celled organisms, or solid debris). Cell membrane folds around particle, pinches off, and forms a vesicle or vacuole. Example: White blood cells engulf harmful bacteria, lysosomes fuse to vesicle containing bacteria, enzymes in lysosome break down bacteria and kill it.

ACTIVE TRANSPORT 3. Bulk Transport: Exocytosis The opposite of endocytosis. A vesicle fuses with the cell membrane and the contents of it are released. One way for cells to remove waste. One way cells release molecules for use somewhere else in the body. Example: How nerve cells send chemical signals to each other.