1. MEMBRANE ACTIVITY

2. Membranes are made of LIPIDS!!!

3. Membranes are made of PHOSPHOLIPIDS
Head
Phosphate Group
HYDROPHILIC
(attracted to water)
Tail
2 Fatty Acids Instead of 3
Hydrophobic (not attracted to water)

4. Phospholipid Bilayer Model

6. MEMBRANE REVIEW!!! WHAT ARE MEMBRANES COMPOSED OF??
DRAW ME A PHOSPHOLIPID AND TELL ME ABOUT ITS 2 MAIN PARTS.
HOW ARE PHOSPHOLIPIDS ARRANGED IN A MEMBRANE, AND WHY?
WHAT ACTS AS “DOORS” TO THE MEMBRANE, ALLOWING THINGS IN AND OUT?

7. MEMBRANE PROTEINS
What Do They Do?
Membrane proteins provide ways for the cell to let things in, and to let things out.
It has different ways to regulate what can pass through, and when.
How Do They Do It?

8. HOW DO WE DO IT? TRANSPORT CHANNELS ENZYME ACTIVITY
Let Molecules of a Certain Size or Shape Pass Into The Cell
ENZYME ACTIVITY
Enzymes in the Membrane Help With Important Chemical Reactions

9. Proteins on the Outside of Cells Recognize Each Other
HOW DO WE DO IT?
CELL-TO-CELL RECOGNITION
Proteins on the Outside of Cells Recognize Each Other
CELL SIGNALING
Chemicals Cause Protein To Change Shape and Signal a Message For The Cell To Do Something

10. DIFFUSION
When Molecules Move From An Area Of High Concentration To An Area Of Low Concentration Through A Medium

11. Diffusion Can Also Occur Through A Semi-Permeable Membrane
Zombie-Diffusion.
It Exists.
Be Prepared.

12. DIFFUSION
Some Membranes Are Selectively Permeable. This Means They Are Designed To Only Let Molecules Of A Certain Size or Shape Through.

13. DIFFUSION Passive Transport Allows For Molecules to Pass Freely.
Active Transport Requires Energy For The Molecules To Pass.
When Passive Transport Happens As A Part Of Diffusion, It Is Called “Facilitated Diffusion”

14. OSMOSIS
The Passive Transport Of Water Through A Selectively Permeable Membrane
Sometimes, instead of chemical molecules moving from areas of high concentration to low (like in Diffusion) the WATER moves instead, because the molecules are too big to pass through the membrane.

15. OSMOSIS It’s All About Balance and Equilibrium
In an ISOTONIC solution, the water flow in and out of the cell is EQUAL. There is a BALANCE.
In a HYPOTONIC solution, the water moves INTO the cell.
In a HYPERTONIC solution, water moves OUT of the cell.

16. VESICLES
Cells Can Create Membranes To Take Things Into and Send Things Out Of The Cell
In EXOCYTOSIS, membranes are used to transport things OUT of a cell.
In ENDOCYTOSIS, membranes are used to bring things INTO a cell.