3.  What is the cytoplasm? ◦ Cyto = “cell” ◦ Plasma= “liquid substance of the cell”  Cytoplasm? ◦ Clear, gelatinous fluid inside the cell

4.  What contains it? ◦ Plasma Membrane  Do all cells have this? ◦ YES!

5.  Cells need an inside & an outside… ◦ separate cell from its environment ◦ cell membrane is the boundary 4 IN food - sugars - proteins - fats salts O2O2 H2OH2O OUT waste - ammonia - salts - CO 2 - H 2 O products - proteins cell needs materials in & products or waste out

6.  Why have a plasma membrane? ◦ Allow nutrients to move in and out of the cell  How does it control how much goes in and out? ◦ Selective permeability  Per= “through”  Meare= “ to glide”  Therefore, what does it mean?

7.  What’s the point for allowing materials in and out of the cell? HOMEOSTASIS!!!!!

8.  How do you build a barrier that keeps the watery contents of the cell separate from the watery environment? 7 What substance do you know that doesn’t mix with water?  FATS   LIPIDS  Remember: oil & water don’t mix!!

9.  Membrane is made of special kind of lipid ◦ phospholipids ◦ “split personality”  Membrane is a double layer ◦ phospholipid bilayer 8 inside cell outside cell lipid “repelled by water” “attracted to water” phosphate

10.  Cell membrane controls what gets in or out  Need to allow some materials — but not all — to pass through the membrane ◦ semi-permeable  only some material can get in or out 9 aa H2OH2O sugar lipidssalt waste So what needs to get across the membrane? O2O2

11.  What molecules can get through the cell membrane directly? ◦ fats and oils can pass directly through 10 inside cell outside cell lipid salt aa H2OH2O sugar waste but… what about other stuff?

12.  Need to make “doors” through membrane ◦ protein channels allow substances in & out  specific channels allow specific material in & out  H 2 O channel, salt channel, sugar channel, etc. 11 inside cell outside cell sugaraa H2OH2O salt waste

13.  Channels are made of proteins ◦ proteins both “like” water & “like” lipids 12 bi-lipid membrane protein channels in bi-lipid membrane

14.  Proteins act as doors in the membrane ◦ channels to move specific molecules through cell membrane 13 HIGH LOW

15. Integral ProteinsPeripheral Proteins  Embedded all the way through the bilayer  Allow ions to pass through the membrane  Bond to only one side of the membrane  Attach to or near integral proteins  Help with ion identification

16. Cholesterol Glycolipid and Glycoprotein  Cell signaling  Maintains membrane fluidity  Secures Proteins  Lipid or Protein with a carbohydrate attached  Provide energy  Cellular recognition

17.  Why do molecules move through membrane if you give them a channel? 16 ? ? HIGH LOW

18.  Diffusion ◦ move from HIGH to LOW concentration 17