1. Chapter 3- Cellular Level of Organization

2. Plasma Membrane F(x): 1. Physical Isolation conditions inside & outside the cell constant to preserve homeostasis 2. Regulation of Exchange with the Environment controls the entry of ions & nutrients, the elimination of wastes, & the release of secretions 3. Sensitivity to the Environment contains variety of receptors that allow the cell to recognize & respond to specific molecules in its environment 4. Structural Support specialized connections b/w plasma membrane or b/w membrane & extracellular materials

3. Phospholipid Bilayer Regulate movement of molecules in/out, semi-permeable Hydrophilic phosphate heads & Hydrophobic lipid tails Cholesterol: large steroid/lipid -helps maintain structure

4. Membrane Proteins: Anchoring- attach plasma membrane to other structures & stabilize its position Recognition- allows immune system cells to recognize “self” vs “nonself” Enzymes- catalyze reactions in cytosol or extracellular fluid Receptors- sensitive to extracellular molecules > ligands Carrier- binds solutes & transport them across membrane (some require ATP) Channels- movement of H2O & small solutes

5. Membrane Carbs: Proteoglycans Glycoproteins Glycolipids Make up layer called Glycocalyx F(x): lubrication & protection Anchoring & locomotion Specificity in binding-alters property of cell’s surface Recognition- “self” vs “nonself”

6. Organelles Outline sheet Section 3-2 : Read pages 68-77

7. Organelles Cytoplasm- contains cytosol & organelles Nucleus- control of metabolism, storage & processing of genetic information, control of protein synthesis Rough ER- modifies & packages newly synthesized proteins Ribosomes- protein synthesis Smooth ER- synthesizes lipids & carbohydrates

8. Golgi body with vesicles- modifies & packages secretions for release through exocytosis, renews or modifies the plasma membrane, packages special enzymes within vesicles for use in the cytoplasm Lysosome- intracellular removal of damaged organelles or pathogens Peroxisome- catabolism of fats & other organic compounds, neutralization of toxic compounds generated in the process

9. Proteasomes- breakdown & recycling of damaged or abnormal intracellular proteins Mitochondria- produces 95% of ATP required by the cell Centrioles- found during cell division, form spindle apparatus Cilia- move fluids/secretions across the cell surface

10. Cytoskeleton- metabolic organization, internal protein framework, gives cytoplasm strength & flexibility Microfilaments- anchor cytoskeleton to integral proteins of plasma membrane, determines consistency of cytoplasm, movement of cell Intermediate filaments- strengthen cell & help maintain its shape, stabilize the positions of organelles, stabilize position of cell to surrounding cells Microtubules- cell strength & rigidity, position of organelles, assist in movement, spindle apparatus, structural components Thick filaments- composed of myosin, interact with actin filaments to produce powerful contractions

11. Nucleus Controls metabolism, storage, & processing of genetic info, control of protein synthesis Contains DNA & enzymes to control cellular activities Genetic code: DNA set of instructions 3 letter word = codon > specific amino acid chains DNA > RNA > proteins The Inner Life of the Cell

12. Diffusion- passive transport Movement of molecules from areas of high concentration to low Down concentration gradient Through phospholipids/ channel proteins

13. Osmosis- diffusion of water Isotonic- equal Hypotonic- salt outside is less = cell bursts (lysis) Hypertonic- more salt outside = water leaves = crenation (shrinking)

14. Carrier Mediated Transport (passive/active) Transportation of ions & organic substrates Characteristics: Specificity: only bind to certain things Saturation: limits to rate Regulation: hormones 1. Facilitated Transport- passive Large polar molecules & ions move across membrane 2. Active- requires E Ion pumps- exchange pumps ex: Na/K Passive vs. Active Transport

15. Vesicular Transport- ATP required 1. Endocytosis- take in using vesicles Receptor mediated target molecules Pinocytosis-liquid Phagocytosis- solids 2. Exocytosis- secretion, hormones/vesicles

16. Facilitated Diffusion vs Active Transport Similarities: Carrier proteins Transport large molecules/ions Differences: FD- w concentration gradient AT- against conc. Gradient AT- requires E, FD doesn’t

17. Transmembrane Potential Charges are separated creating a potential difference Unequal charge across plasma membrane is transmembrane potential Resting potential= -10mV to -100mV, depending on cell Minus sign signifies inside of plasma membrane contains an excess of – charges compared with outside Creates potential E

18. Cell Cycle Interphase- cell increases in mass, doubles its cytoplasm & duplicates its DNA G1- cytoplasm doubles S- DNA is copied G2- proteins/enzymes required for cell division are made Mitosis Prophase- chromosomes condense Metaphase- chromosomes line up in middle Anaphase- separation Telophase- condense Cytokinesis- division into 2 daughter cells Late anaphase > telophase Marks end of cell division Cell Cycle and Mitosis

19. Regulation of Cell cycle Proteins & enzymes are responsible 1. Cyclins- family of proteins that increase and decrease in number during cell cycle, bind to kinases to activate them M cyclins- during mitosis S cyclins- during interphase 2. Kinases- Cdk (cyclin dependent kinases)-family of enzymes that drive the cell cycle, active only when bound to cyclin When damage is found, the checkpoint uses a signal mechanism either to stall the cell cycle until repairs are made or, if repairs cannot be made, to target the cell for destruction via apoptosis

20. Cancer Uncontrolled cell division- tumor growth Proto-oncogenes- naturally occurring, normally promote cell division when on Oncogene- mutated form, permanently spin cell cycle Tumor Suppressor Genes- naturally occurring, stop cell cycle

21. Formation of Cancer Starts with a mutation Genetic, virus, environment (smoking, radiation, UV) Cell becomes non-functional, not density dependent, and does not stick together = primary tumor Angiogenesis- formation of blood supply Benign-doesn’t spread Malignant- will spread Uses blood or lymphatic system to spread = Metastasis =secondary tumor Cancer Video

22. Cell Differentiation Development of specific cellular features All cells throughout the body contain the same set of chromosomes & genes, but a different set of genes has been turned off All have 46 chromosomes Liver cells don’t have genes for production of insulin turned on Stem cells- undifferentiated and can become many cell types