1. The Cell External Boundary Nucleus Cytoplasm Cell Membrane · plant &animal cells ·semipermeable ·lipid bilayer -hydrophobic lipids -hydrophillic phosphates ·fluid mosaic model -dynamic movement Cell Wall · only plant cells ·made of cellulose -complex carbohydrate -interwoven strands ·strength ·protection Nonmembranous Organelles ·Ribosomes -rRNA -protein synthesis -rough ER ·Microtubules/filaments -form cytoskeleton -shape, transport, cell division ·Centrioles -spindle fibers in cell division ·Cilia & Flagella -movement Three Components Nuclear Membrane · double membrane ·contains pores -allows molecules in and out (RNA, nutrients) N ucleolus · makes ribosomes (RNA) N ucleoplasm · contains chromatin -becomes condensed into chromosomes during cell division Membranous Organelles SINGLE MEMBRANES ·Cell Membrane ·Endoplasmic Reticulum -Rough has ribosomes *transport *protein synthesis -Smooth no ribosomes *fat metabolism *detoxification *perioxisomes ·Golgi Apparatus -modifies molecules -packages vesicles -ships within & out - makes lysosomes ·Lysosomes -contain enzymes -digest food vacuoles -destroys old cells ·Vacuoles/Vesicles -big/small storage sacs DOUBLE MEMBRANES ·Mitochondria (P & A) -cristae-> inner membrane -aerobic cellular respiration ·Chloroplast (P only!) -contain chlorophyll -photosynthesis

2. Exchange Through Membranes Kinetic Energy Theory –All molecules are in a constant state of motion Solids vibrate in place Liquids move slowly but freely Gases move quickly and freely –Molecules tend to move toward a state of dynamic equilibrium (equal space in between molecules)

3. Passive Transport NO ENERGY IS USED!! Diffusion Net movement of molecules from high concentration to low concentration across a semi permeable membrane until a dynamic equilibrium is reached

4. NO ENERGY IS USED!!!!!!!!!

5. Still Passive! OSMOSIS No Energy Used Diffusion of water across a semi permeable membrane until dynamic equilibrium is reached

6. Hypertonic vs Hypotonic Hypertonic = more crowded (higher concentration of solute) Hypotonic = less crowded (lower concentration of solute) Isotonic = equal concentrations of solute on both sides of a membrane Intracellularextra cellular Semi Permeable membrane Water molecules Salt molecules Which way would the water move? Into or out of the cell?

7. The rigidity of the cell wall prevents the cell from collapsing in a plant cell. An animal cell has no such protection

8. And……. Still Passive Facilitated diffusion –No energy used –Carrier proteins Change shape –Ion channels (easy pass!) Glucose enters this way

9. Finally, Active Transport This requires energy to be used by the cell Moves molecules from low to high concentration Uses carrier proteins Example: Na ions are pumped out of the cell and K ions are pumped into the cell Carrier protein

10. More Active Transport For large particles like food to cross they are first wrapped in membrane Endocytosis : enter the cell Exocytosis: exit the cell Phagocytosis: large particles engulfed –WBC’s engulf bacteria this way Pinocytosis: liquids engulfed

11. Organize your thoughts on transport